Redis 集群模式下的数据分片机制 – 兰陵美酒郁金香的个人博客

在博客中,我介绍了 Redis 哨兵机制的搭建和Redis 主从读写分离的优势,此次分享的是Redis 数据分片集群部署

在看这篇文章之前,如果你对读写分离与哨兵机制还不够清楚的情况下,请优先查阅我前两篇文章。

Redis| 主从读写分离

Redis 哨兵

我们知道 Redis 主从读写分离它解决了在高并发场景下读数据的瓶颈,而哨兵机制解决了在主从读写分离场景下,由于主节点宕机造成不可恢复,从而立即自动选举一个从节点主动接管主节点的场景。

但是他们依然没有解决大量数据积压的问题。我们可能听过Mysql在存储大数据时的分库分表策略,其实Redis也拥有这一机制。

因此下面的内容就是向大分享这样的一个实验。

我的实验环境是 Cenots 7、Redis 6.06 版本

第一步:安装依赖

yum install -y ruby rubygems

1	yum install -y ruby rubygems

第二步:准备redis节点

由于 Redis 集群最低要求为三主三从,即 6 个节点,因此我在路径:/mnt/下创建了6个目录如下图所示

每个目录中分别存储着各自 redis.conf 配置文件 ,在实验中我将会开启Redis 7000、7001、7002、7003、7004、7005端口。

我选取目录名为 7000 下的配置文件内容如下:

# Redis configuration file example.
#
# Note that in order to read the configuration file, Redis must be
# started with the file path as first argument:
#
# ./redis-server /path/to/redis.conf

# Note on units: when memory size is needed, it is possible to specify
# it in the usual form of 1k 5GB 4M and so forth:
#
# 1k => 1000 bytes
# 1kb => 1024 bytes
# 1m => 1000000 bytes
# 1mb => 1024*1024 bytes
# 1g => 1000000000 bytes
# 1gb => 1024*1024*1024 bytes
#
# units are case insensitive so 1GB 1Gb 1gB are all the same.

################################## INCLUDES ###################################

# Include one or more other config files here.  This is useful if you
# have a standard template that goes to all Redis servers but also need
# to customize a few per-server settings.  Include files can include
# other files, so use this wisely.
#
# Notice option "include" won't be rewritten by command "CONFIG REWRITE"
# from admin or Redis Sentinel. Since Redis always uses the last processed
# line as value of a configuration directive, you'd better put includes
# at the beginning of this file to avoid overwriting config change at runtime.
#
# If instead you are interested in using includes to override configuration
# options, it is better to use include as the last line.
#
# include /path/to/local.conf
# include /path/to/other.conf

################################## MODULES #####################################

# Load modules at startup. If the server is not able to load modules
# it will abort. It is possible to use multiple loadmodule directives.
#
# loadmodule /path/to/my_module.so
# loadmodule /path/to/other_module.so

################################## NETWORK #####################################

# By default, if no "bind" configuration directive is specified, Redis listens
# for connections from all the network interfaces available on the server.
# It is possible to listen to just one or multiple selected interfaces using
# the "bind" configuration directive, followed by one or more IP addresses.
#
# Examples:
#
# bind 192.168.1.100 10.0.0.1
# bind 127.0.0.1 ::1
#
# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
# internet, binding to all the interfaces is dangerous and will expose the
# instance to everybody on the internet. So by default we uncomment the
# following bind directive, that will force Redis to listen only into
# the IPv4 loopback interface address (this means Redis will be able to
# accept connections only from clients running into the same computer it
# is running).
#
# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
# JUST COMMENT THE FOLLOWING LINE.
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bind 0.0.0.0

# Protected mode is a layer of security protection, in order to avoid that
# Redis instances left open on the internet are accessed and exploited.
#
# When protected mode is on and if:
#
# 1) The server is not binding explicitly to a set of addresses using the
#    "bind" directive.
# 2) No password is configured.
#
# The server only accepts connections from clients connecting from the
# IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from Unix domain
# sockets.
#
# By default protected mode is enabled. You should disable it only if
# you are sure you want clients from other hosts to connect to Redis
# even if no authentication is configured, nor a specific set of interfaces
# are explicitly listed using the "bind" directive.
protected-mode no

# Accept connections on the specified port, default is 6379 (IANA #815344).
# If port 0 is specified Redis will not listen on a TCP socket.
port 7000

# TCP listen() backlog.
#
# In high requests-per-second environments you need an high backlog in order
# to avoid slow clients connections issues. Note that the Linux kernel
# will silently truncate it to the value of /proc/sys/net/core/somaxconn so
# make sure to raise both the value of somaxconn and tcp_max_syn_backlog
# in order to get the desired effect.
tcp-backlog 511

# Unix socket.
#
# Specify the path for the Unix socket that will be used to listen for
# incoming connections. There is no default, so Redis will not listen
# on a unix socket when not specified.
#
# unixsocket /tmp/redis.sock
# unixsocketperm 700

# Close the connection after a client is idle for N seconds (0 to disable)
timeout 0

# TCP keepalive.
#
# If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence
# of communication. This is useful for two reasons:
#
# 1) Detect dead peers.
# 2) Take the connection alive from the point of view of network
#    equipment in the middle.
#
# On Linux, the specified value (in seconds) is the period used to send ACKs.
# Note that to close the connection the double of the time is needed.
# On other kernels the period depends on the kernel configuration.
#
# A reasonable value for this option is 300 seconds, which is the new
# Redis default starting with Redis 3.2.1.
tcp-keepalive 300

################################# TLS/SSL #####################################

# By default, TLS/SSL is disabled. To enable it, the "tls-port" configuration
# directive can be used to define TLS-listening ports. To enable TLS on the
# default port, use:
#
# port 0
# tls-port 6379

# Configure a X.509 certificate and private key to use for authenticating the
# server to connected clients, masters or cluster peers.  These files should be
# PEM formatted.
#
# tls-cert-file redis.crt
# tls-key-file redis.key

# Configure a DH parameters file to enable Diffie-Hellman (DH) key exchange:
#
# tls-dh-params-file redis.dh

# Configure a CA certificate(s) bundle or directory to authenticate TLS/SSL
# clients and peers.  Redis requires an explicit configuration of at least one
# of these, and will not implicitly use the system wide configuration.
#
# tls-ca-cert-file ca.crt
# tls-ca-cert-dir /etc/ssl/certs

# By default, clients (including replica servers) on a TLS port are required
# to authenticate using valid client side certificates.
#
# It is possible to disable authentication using this directive.
#
# tls-auth-clients no

# By default, a Redis replica does not attempt to establish a TLS connection
# with its master.
#
# Use the following directive to enable TLS on replication links.
#
# tls-replication yes

# By default, the Redis Cluster bus uses a plain TCP connection. To enable
# TLS for the bus protocol, use the following directive:
#
# tls-cluster yes

# Explicitly specify TLS versions to support. Allowed values are case insensitive
# and include "TLSv1", "TLSv1.1", "TLSv1.2", "TLSv1.3" (OpenSSL >= 1.1.1) or
# any combination. To enable only TLSv1.2 and TLSv1.3, use:
#
# tls-protocols "TLSv1.2 TLSv1.3"

# Configure allowed ciphers.  See the ciphers(1ssl) manpage for more information
# about the syntax of this string.
#
# Note: this configuration applies only to <= TLSv1.2.
#
# tls-ciphers DEFAULT:!MEDIUM

# Configure allowed TLSv1.3 ciphersuites.  See the ciphers(1ssl) manpage for more
# information about the syntax of this string, and specifically for TLSv1.3
# ciphersuites.
#
# tls-ciphersuites TLS_CHACHA20_POLY1305_SHA256

# When choosing a cipher, use the server's preference instead of the client
# preference. By default, the server follows the client's preference.
#
# tls-prefer-server-ciphers yes

# By default, TLS session caching is enabled to allow faster and less expensive
# reconnections by clients that support it. Use the following directive to disable
# caching.
#
# tls-session-caching no

# Change the default number of TLS sessions cached. A zero value sets the cache
# to unlimited size. The default size is 20480.
#
# tls-session-cache-size 5000

# Change the default timeout of cached TLS sessions. The default timeout is 300
# seconds.
#
# tls-session-cache-timeout 60

################################# GENERAL #####################################

# By default Redis does not run as a daemon. Use 'yes' if you need it.
# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
daemonize yes

# If you run Redis from upstart or systemd, Redis can interact with your
# supervision tree. Options:
#   supervised no      - no supervision interaction
#   supervised upstart - signal upstart by putting Redis into SIGSTOP mode
#   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
#   supervised auto    - detect upstart or systemd method based on
#                        UPSTART_JOB or NOTIFY_SOCKET environment variables
# Note: these supervision methods only signal "process is ready."
#       They do not enable continuous liveness pings back to your supervisor.
supervised no

# If a pid file is specified, Redis writes it where specified at startup
# and removes it at exit.
#
# When the server runs non daemonized, no pid file is created if none is
# specified in the configuration. When the server is daemonized, the pid file
# is used even if not specified, defaulting to "/var/run/redis.pid".
#
# Creating a pid file is best effort: if Redis is not able to create it
# nothing bad happens, the server will start and run normally.
pidfile "/var/run/redis_6379.pid"

# Specify the server verbosity level.
# This can be one of:
# debug (a lot of information, useful for development/testing)
# verbose (many rarely useful info, but not a mess like the debug level)
# notice (moderately verbose, what you want in production probably)
# warning (only very important / critical messages are logged)
loglevel notice

# Specify the log file name. Also the empty string can be used to force
# Redis to log on the standard output. Note that if you use standard
# output for logging but daemonize, logs will be sent to /dev/null
logfile ""

# To enable logging to the system logger, just set 'syslog-enabled' to yes,
# and optionally update the other syslog parameters to suit your needs.
# syslog-enabled no

# Specify the syslog identity.
# syslog-ident redis

# Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.
# syslog-facility local0

# Set the number of databases. The default database is DB 0, you can select
# a different one on a per-connection basis using SELECT <dbid> where
# dbid is a number between 0 and 'databases'-1
databases 16

# By default Redis shows an ASCII art logo only when started to log to the
# standard output and if the standard output is a TTY. Basically this means
# that normally a logo is displayed only in interactive sessions.
#
# However it is possible to force the pre-4.0 behavior and always show a
# ASCII art logo in startup logs by setting the following option to yes.
always-show-logo yes

################################ SNAPSHOTTING  ################################
#
# Save the DB on disk:
#
#   save <seconds> <changes>
#
#   Will save the DB if both the given number of seconds and the given
#   number of write operations against the DB occurred.
#
#   In the example below the behaviour will be to save:
#   after 900 sec (15 min) if at least 1 key changed
#   after 300 sec (5 min) if at least 10 keys changed
#   after 60 sec if at least 10000 keys changed
#
#   Note: you can disable saving completely by commenting out all "save" lines.
#
#   It is also possible to remove all the previously configured save
#   points by adding a save directive with a single empty string argument
#   like in the following example:
#
#   save ""

save 900 1
save 300 10
save 60 10000

# By default Redis will stop accepting writes if RDB snapshots are enabled
# (at least one save point) and the latest background save failed.
# This will make the user aware (in a hard way) that data is not persisting
# on disk properly, otherwise chances are that no one will notice and some
# disaster will happen.
#
# If the background saving process will start working again Redis will
# automatically allow writes again.
#
# However if you have setup your proper monitoring of the Redis server
# and persistence, you may want to disable this feature so that Redis will
# continue to work as usual even if there are problems with disk,
# permissions, and so forth.
stop-writes-on-bgsave-error yes

# Compress string objects using LZF when dump .rdb databases?
# For default that's set to 'yes' as it's almost always a win.
# If you want to save some CPU in the saving child set it to 'no' but
# the dataset will likely be bigger if you have compressible values or keys.
rdbcompression yes

# Since version 5 of RDB a CRC64 checksum is placed at the end of the file.
# This makes the format more resistant to corruption but there is a performance
# hit to pay (around 10%) when saving and loading RDB files, so you can disable it
# for maximum performances.
#
# RDB files created with checksum disabled have a checksum of zero that will
# tell the loading code to skip the check.
rdbchecksum yes

# The filename where to dump the DB
dbfilename "dump-7000.rdb"

# Remove RDB files used by replication in instances without persistence
# enabled. By default this option is disabled, however there are environments
# where for regulations or other security concerns, RDB files persisted on
# disk by masters in order to feed replicas, or stored on disk by replicas
# in order to load them for the initial synchronization, should be deleted
# ASAP. Note that this option ONLY WORKS in instances that have both AOF
# and RDB persistence disabled, otherwise is completely ignored.
#
# An alternative (and sometimes better) way to obtain the same effect is
# to use diskless replication on both master and replicas instances. However
# in the case of replicas, diskless is not always an option.
rdb-del-sync-files no

# The working directory.
#
# The DB will be written inside this directory, with the filename specified
# above using the 'dbfilename' configuration directive.
#
# The Append Only File will also be created inside this directory.
#
# Note that you must specify a directory here, not a file name.
dir "/mnt/7000"

################################# REPLICATION #################################

# Master-Replica replication. Use replicaof to make a Redis instance a copy of
# another Redis server. A few things to understand ASAP about Redis replication.
#
#   +------------------+      +---------------+
#   |      Master      | ---> |    Replica    |
#   | (receive writes) |      |  (exact copy) |
#   +------------------+      +---------------+
#
# 1) Redis replication is asynchronous, but you can configure a master to
#    stop accepting writes if it appears to be not connected with at least
#    a given number of replicas.
# 2) Redis replicas are able to perform a partial resynchronization with the
#    master if the replication link is lost for a relatively small amount of
#    time. You may want to configure the replication backlog size (see the next
#    sections of this file) with a sensible value depending on your needs.
# 3) Replication is automatic and does not need user intervention. After a
#    network partition replicas automatically try to reconnect to masters
#    and resynchronize with them.
#
# replicaof <masterip> <masterport>

# If the master is password protected (using the "requirepass" configuration
# directive below) it is possible to tell the replica to authenticate before
# starting the replication synchronization process, otherwise the master will
# refuse the replica request.
#
# masterauth <master-password>
#
# However this is not enough if you are using Redis ACLs (for Redis version
# 6 or greater), and the default user is not capable of running the PSYNC
# command and/or other commands needed for replication. In this case it's
# better to configure a special user to use with replication, and specify the
# masteruser configuration as such:
#
# masteruser <username>
#
# When masteruser is specified, the replica will authenticate against its
# master using the new AUTH form: AUTH <username> <password>.

# When a replica loses its connection with the master, or when the replication
# is still in progress, the replica can act in two different ways:
#
# 1) if replica-serve-stale-data is set to 'yes' (the default) the replica will
#    still reply to client requests, possibly with out of date data, or the
#    data set may just be empty if this is the first synchronization.
#
# 2) if replica-serve-stale-data is set to 'no' the replica will reply with
#    an error "SYNC with master in progress" to all the kind of commands
#    but to INFO, replicaOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG,
#    SUBSCRIBE, UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, PUBLISH, PUBSUB,
#    COMMAND, POST, HOST: and LATENCY.
#
replica-serve-stale-data yes

# You can configure a replica instance to accept writes or not. Writing against
# a replica instance may be useful to store some ephemeral data (because data
# written on a replica will be easily deleted after resync with the master) but
# may also cause problems if clients are writing to it because of a
# misconfiguration.
#
# Since Redis 2.6 by default replicas are read-only.
#
# Note: read only replicas are not designed to be exposed to untrusted clients
# on the internet. It's just a protection layer against misuse of the instance.
# Still a read only replica exports by default all the administrative commands
# such as CONFIG, DEBUG, and so forth. To a limited extent you can improve
# security of read only replicas using 'rename-command' to shadow all the
# administrative / dangerous commands.
replica-read-only yes

# Replication SYNC strategy: disk or socket.
#
# New replicas and reconnecting replicas that are not able to continue the
# replication process just receiving differences, need to do what is called a
# "full synchronization". An RDB file is transmitted from the master to the
# replicas.
#
# The transmission can happen in two different ways:
#
# 1) Disk-backed: The Redis master creates a new process that writes the RDB
#                 file on disk. Later the file is transferred by the parent
#                 process to the replicas incrementally.
# 2) Diskless: The Redis master creates a new process that directly writes the
#              RDB file to replica sockets, without touching the disk at all.
#
# With disk-backed replication, while the RDB file is generated, more replicas
# can be queued and served with the RDB file as soon as the current child
# producing the RDB file finishes its work. With diskless replication instead
# once the transfer starts, new replicas arriving will be queued and a new
# transfer will start when the current one terminates.
#
# When diskless replication is used, the master waits a configurable amount of
# time (in seconds) before starting the transfer in the hope that multiple
# replicas will arrive and the transfer can be parallelized.
#
# With slow disks and fast (large bandwidth) networks, diskless replication
# works better.
repl-diskless-sync no

# When diskless replication is enabled, it is possible to configure the delay
# the server waits in order to spawn the child that transfers the RDB via socket
# to the replicas.
#
# This is important since once the transfer starts, it is not possible to serve
# new replicas arriving, that will be queued for the next RDB transfer, so the
# server waits a delay in order to let more replicas arrive.
#
# The delay is specified in seconds, and by default is 5 seconds. To disable
# it entirely just set it to 0 seconds and the transfer will start ASAP.
repl-diskless-sync-delay 5

# -----------------------------------------------------------------------------
# WARNING: RDB diskless load is experimental. Since in this setup the replica
# does not immediately store an RDB on disk, it may cause data loss during
# failovers. RDB diskless load + Redis modules not handling I/O reads may also
# cause Redis to abort in case of I/O errors during the initial synchronization
# stage with the master. Use only if your do what you are doing.
# -----------------------------------------------------------------------------
#
# Replica can load the RDB it reads from the replication link directly from the
# socket, or store the RDB to a file and read that file after it was completely
# recived from the master.
#
# In many cases the disk is slower than the network, and storing and loading
# the RDB file may increase replication time (and even increase the master's
# Copy on Write memory and salve buffers).
# However, parsing the RDB file directly from the socket may mean that we have
# to flush the contents of the current database before the full rdb was
# received. For this reason we have the following options:
#
# "disabled"    - Don't use diskless load (store the rdb file to the disk first)
# "on-empty-db" - Use diskless load only when it is completely safe.
# "swapdb"      - Keep a copy of the current db contents in RAM while parsing
#                 the data directly from the socket. note that this requires
#                 sufficient memory, if you don't have it, you risk an OOM kill.
repl-diskless-load disabled

# Replicas send PINGs to server in a predefined interval. It's possible to
# change this interval with the repl_ping_replica_period option. The default
# value is 10 seconds.
#
# repl-ping-replica-period 10

# The following option sets the replication timeout for:
#
# 1) Bulk transfer I/O during SYNC, from the point of view of replica.
# 2) Master timeout from the point of view of replicas (data, pings).
# 3) Replica timeout from the point of view of masters (REPLCONF ACK pings).
#
# It is important to make sure that this value is greater than the value
# specified for repl-ping-replica-period otherwise a timeout will be detected
# every time there is low traffic between the master and the replica.
#
# repl-timeout 60

# Disable TCP_NODELAY on the replica socket after SYNC?
#
# If you select "yes" Redis will use a smaller number of TCP packets and
# less bandwidth to send data to replicas. But this can add a delay for
# the data to appear on the replica side, up to 40 milliseconds with
# Linux kernels using a default configuration.
#
# If you select "no" the delay for data to appear on the replica side will
# be reduced but more bandwidth will be used for replication.
#
# By default we optimize for low latency, but in very high traffic conditions
# or when the master and replicas are many hops away, turning this to "yes" may
# be a good idea.
repl-disable-tcp-nodelay no

# Set the replication backlog size. The backlog is a buffer that accumulates
# replica data when replicas are disconnected for some time, so that when a
# replica wants to reconnect again, often a full resync is not needed, but a
# partial resync is enough, just passing the portion of data the replica
# missed while disconnected.
#
# The bigger the replication backlog, the longer the time the replica can be
# disconnected and later be able to perform a partial resynchronization.
#
# The backlog is only allocated once there is at least a replica connected.
#
# repl-backlog-size 1mb

# After a master has no longer connected replicas for some time, the backlog
# will be freed. The following option configures the amount of seconds that
# need to elapse, starting from the time the last replica disconnected, for
# the backlog buffer to be freed.
#
# Note that replicas never free the backlog for timeout, since they may be
# promoted to masters later, and should be able to correctly "partially
# resynchronize" with the replicas: hence they should always accumulate backlog.
#
# A value of 0 means to never release the backlog.
#
# repl-backlog-ttl 3600

# The replica priority is an integer number published by Redis in the INFO
# output. It is used by Redis Sentinel in order to select a replica to promote
# into a master if the master is no longer working correctly.
#
# A replica with a low priority number is considered better for promotion, so
# for instance if there are three replicas with priority 10, 100, 25 Sentinel
# will pick the one with priority 10, that is the lowest.
#
# However a special priority of 0 marks the replica as not able to perform the
# role of master, so a replica with priority of 0 will never be selected by
# Redis Sentinel for promotion.
#
# By default the priority is 100.
replica-priority 100

# It is possible for a master to stop accepting writes if there are less than
# N replicas connected, having a lag less or equal than M seconds.
#
# The N replicas need to be in "online" state.
#
# The lag in seconds, that must be <= the specified value, is calculated from
# the last ping received from the replica, that is usually sent every second.
#
# This option does not GUARANTEE that N replicas will accept the write, but
# will limit the window of exposure for lost writes in case not enough replicas
# are available, to the specified number of seconds.
#
# For example to require at least 3 replicas with a lag <= 10 seconds use:
#
# min-replicas-to-write 3
# min-replicas-max-lag 10
#
# Setting one or the other to 0 disables the feature.
#
# By default min-replicas-to-write is set to 0 (feature disabled) and
# min-replicas-max-lag is set to 10.

# A Redis master is able to list the address and port of the attached
# replicas in different ways. For example the "INFO replication" section
# offers this information, which is used, among other tools, by
# Redis Sentinel in order to discover replica instances.
# Another place where this info is available is in the output of the
# "ROLE" command of a master.
#
# The listed IP and address normally reported by a replica is obtained
# in the following way:
#
#   IP: The address is auto detected by checking the peer address
#   of the socket used by the replica to connect with the master.
#
#   Port: The port is communicated by the replica during the replication
#   handshake, and is normally the port that the replica is using to
#   listen for connections.
#
# However when port forwarding or Network Address Translation (NAT) is
# used, the replica may be actually reachable via different IP and port
# pairs. The following two options can be used by a replica in order to
# report to its master a specific set of IP and port, so that both INFO
# and ROLE will report those values.
#
# There is no need to use both the options if you need to override just
# the port or the IP address.
#
# replica-announce-ip 5.5.5.5
# replica-announce-port 1234

############################### KEYS TRACKING #################################

# Redis implements server assisted support for client side caching of values.
# This is implemented using an invalidation table that remembers, using
# 16 millions of slots, what clients may have certain subsets of keys. In turn
# this is used in order to send invalidation messages to clients. Please
# to understand more about the feature check this page:
#
#   https://redis.io/topics/client-side-caching
#
# When tracking is enabled for a client, all the read only queries are assumed
# to be cached: this will force Redis to store information in the invalidation
# table. When keys are modified, such information is flushed away, and
# invalidation messages are sent to the clients. However if the workload is
# heavily dominated by reads, Redis could use more and more memory in order
# to track the keys fetched by many clients.
#
# For this reason it is possible to configure a maximum fill value for the
# invalidation table. By default it is set to 1M of keys, and once this limit
# is reached, Redis will start to evict keys in the invalidation table
# even if they were not modified, just to reclaim memory: this will in turn
# force the clients to invalidate the cached values. Basically the table
# maximum size is a trade off between the memory you want to spend server
# side to track information about who cached what, and the ability of clients
# to retain cached objects in memory.
#
# If you set the value to 0, it means there are no limits, and Redis will
# retain as many keys as needed in the invalidation table.
# In the "stats" INFO section, you can find information about the number of
# keys in the invalidation table at every given moment.
#
# Note: when key tracking is used in broadcasting mode, no memory is used
# in the server side so this setting is useless.
#
# tracking-table-max-keys 1000000

################################## SECURITY ###################################

# Warning: since Redis is pretty fast an outside user can try up to
# 1 million passwords per second against a modern box. This means that you
# should use very strong passwords, otherwise they will be very easy to break.
# Note that because the password is really a shared secret between the client
# and the server, and should not be memorized by any human, the password
# can be easily a long string from /dev/urandom or whatever, so by using a
# long and unguessable password no brute force attack will be possible.

# Redis ACL users are defined in the following format:
#
#   user <username> ... acl rules ...
#
# For example:
#
#   user worker +@list +@connection ~jobs:* on >ffa9203c493aa99
#
# The special username "default" is used for new connections. If this user
# has the "nopass" rule, then new connections will be immediately authenticated
# as the "default" user without the need of any password provided via the
# AUTH command. Otherwise if the "default" user is not flagged with "nopass"
# the connections will start in not authenticated state, and will require
# AUTH (or the HELLO command AUTH option) in order to be authenticated and
# start to work.
#
# The ACL rules that describe what an user can do are the following:
#
#  on           Enable the user: it is possible to authenticate as this user.
#  off          Disable the user: it's no longer possible to authenticate
#               with this user, however the already authenticated connections
#               will still work.
#  +<command>   Allow the execution of that command
#  -<command>   Disallow the execution of that command
#  +@<category> Allow the execution of all the commands in such category
#               with valid categories are like @admin, @set, @sortedset, ...
#               and so forth, see the full list in the server.c file where
#               the Redis command table is described and defined.
#               The special category @all means all the commands, but currently
#               present in the server, and that will be loaded in the future
#               via modules.
#  +<command>|subcommand    Allow a specific subcommand of an otherwise
#                           disabled command. Note that this form is not
#                           allowed as negative like -DEBUG|SEGFAULT, but
#                           only additive starting with "+".
#  allcommands  Alias for +@all. Note that it implies the ability to execute
#               all the future commands loaded via the modules system.
#  nocommands   Alias for -@all.
#  ~<pattern>   Add a pattern of keys that can be mentioned as part of
#               commands. For instance ~* allows all the keys. The pattern
#               is a glob-style pattern like the one of KEYS.
#               It is possible to specify multiple patterns.
#  allkeys      Alias for ~*
#  resetkeys    Flush the list of allowed keys patterns.
#  ><password>  Add this passowrd to the list of valid password for the user.
#               For example >mypass will add "mypass" to the list.
#               This directive clears the "nopass" flag (see later).
#  <<password>  Remove this password from the list of valid passwords.
#  nopass       All the set passwords of the user are removed, and the user
#               is flagged as requiring no password: it means that every
#               password will work against this user. If this directive is
#               used for the default user, every new connection will be
#               immediately authenticated with the default user without
#               any explicit AUTH command required. Note that the "resetpass"
#               directive will clear this condition.
#  resetpass    Flush the list of allowed passwords. Moreover removes the
#               "nopass" status. After "resetpass" the user has no associated
#               passwords and there is no way to authenticate without adding
#               some password (or setting it as "nopass" later).
#  reset        Performs the following actions: resetpass, resetkeys, off,
#               -@all. The user returns to the same state it has immediately
#               after its creation.
#
# ACL rules can be specified in any order: for instance you can start with
# passwords, then flags, or key patterns. However note that the additive
# and subtractive rules will CHANGE MEANING depending on the ordering.
# For instance see the following example:
#
#   user alice on +@all -DEBUG ~* >somepassword
#
# This will allow "alice" to use all the commands with the exception of the
# DEBUG command, since +@all added all the commands to the set of the commands
# alice can use, and later DEBUG was removed. However if we invert the order
# of two ACL rules the result will be different:
#
#   user alice on -DEBUG +@all ~* >somepassword
#
# Now DEBUG was removed when alice had yet no commands in the set of allowed
# commands, later all the commands are added, so the user will be able to
# execute everything.
#
# Basically ACL rules are processed left-to-right.
#
# For more information about ACL configuration please refer to
# the Redis web site at https://redis.io/topics/acl

# ACL LOG
#
# The ACL Log tracks failed commands and authentication events associated
# with ACLs. The ACL Log is useful to troubleshoot failed commands blocked
# by ACLs. The ACL Log is stored in memory. You can reclaim memory with
# ACL LOG RESET. Define the maximum entry length of the ACL Log below.
acllog-max-len 128

# Using an external ACL file
#
# Instead of configuring users here in this file, it is possible to use
# a stand-alone file just listing users. The two methods cannot be mixed:
# if you configure users here and at the same time you activate the exteranl
# ACL file, the server will refuse to start.
#
# The format of the external ACL user file is exactly the same as the
# format that is used inside redis.conf to describe users.
#
# aclfile /etc/redis/users.acl

# IMPORTANT NOTE: starting with Redis 6 "requirepass" is just a compatiblity
# layer on top of the new ACL system. The option effect will be just setting
# the password for the default user. Clients will still authenticate using
# AUTH <password> as usually, or more explicitly with AUTH default <password>
# if they follow the new protocol: both will work.
#
# requirepass foobared

# Command renaming (DEPRECATED).
#
# ------------------------------------------------------------------------
# WARNING: avoid using this option if possible. Instead use ACLs to remove
# commands from the default user, and put them only in some admin user you
# create for administrative purposes.
# ------------------------------------------------------------------------
#
# It is possible to change the name of dangerous commands in a shared
# environment. For instance the CONFIG command may be renamed into something
# hard to guess so that it will still be available for internal-use tools
# but not available for general clients.
#
# Example:
#
# rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
#
# It is also possible to completely kill a command by renaming it into
# an empty string:
#
# rename-command CONFIG ""
#
# Please note that changing the name of commands that are logged into the
# AOF file or transmitted to replicas may cause problems.

################################### CLIENTS ####################################

# Set the max number of connected clients at the same time. By default
# this limit is set to 10000 clients, however if the Redis server is not
# able to configure the process file limit to allow for the specified limit
# the max number of allowed clients is set to the current file limit
# minus 32 (as Redis reserves a few file descriptors for internal uses).
#
# Once the limit is reached Redis will close all the new connections sending
# an error 'max number of clients reached'.
#
# IMPORTANT: When Redis Cluster is used, the max number of connections is also
# shared with the cluster bus: every node in the cluster will use two
# connections, one incoming and another outgoing. It is important to size the
# limit accordingly in case of very large clusters.
#
# maxclients 10000

############################## MEMORY MANAGEMENT ################################

# Set a memory usage limit to the specified amount of bytes.
# When the memory limit is reached Redis will try to remove keys
# according to the eviction policy selected (see maxmemory-policy).
#
# If Redis can't remove keys according to the policy, or if the policy is
# set to 'noeviction', Redis will start to reply with errors to commands
# that would use more memory, like SET, LPUSH, and so on, and will continue
# to reply to read-only commands like GET.
#
# This option is usually useful when using Redis as an LRU or LFU cache, or to
# set a hard memory limit for an instance (using the 'noeviction' policy).
#
# WARNING: If you have replicas attached to an instance with maxmemory on,
# the size of the output buffers needed to feed the replicas are subtracted
# from the used memory count, so that network problems / resyncs will
# not trigger a loop where keys are evicted, and in turn the output
# buffer of replicas is full with DELs of keys evicted triggering the deletion
# of more keys, and so forth until the database is completely emptied.
#
# In short... if you have replicas attached it is suggested that you set a lower
# limit for maxmemory so that there is some free RAM on the system for replica
# output buffers (but this is not needed if the policy is 'noeviction').
#
# maxmemory <bytes>

# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
# is reached. You can select one from the following behaviors:
#
# volatile-lru -> Evict using approximated LRU, only keys with an expire set.
# allkeys-lru -> Evict any key using approximated LRU.
# volatile-lfu -> Evict using approximated LFU, only keys with an expire set.
# allkeys-lfu -> Evict any key using approximated LFU.
# volatile-random -> Remove a random key having an expire set.
# allkeys-random -> Remove a random key, any key.
# volatile-ttl -> Remove the key with the nearest expire time (minor TTL)
# noeviction -> Don't evict anything, just return an error on write operations.
#
# LRU means Least Recently Used
# LFU means Least Frequently Used
#
# Both LRU, LFU and volatile-ttl are implemented using approximated
# randomized algorithms.
#
# Note: with any of the above policies, Redis will return an error on write
#       operations, when there are no suitable keys for eviction.
#
#       At the date of writing these commands are: set setnx setex append
#       incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd
#       sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby
#       zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby
#       getset mset msetnx exec sort
#
# The default is:
#
# maxmemory-policy noeviction

# LRU, LFU and minimal TTL algorithms are not precise algorithms but approximated
# algorithms (in order to save memory), so you can tune it for speed or
# accuracy. For default Redis will check five keys and pick the one that was
# used less recently, you can change the sample size using the following
# configuration directive.
#
# The default of 5 produces good enough results. 10 Approximates very closely
# true LRU but costs more CPU. 3 is faster but not very accurate.
#
# maxmemory-samples 5

# Starting from Redis 5, by default a replica will ignore its maxmemory setting
# (unless it is promoted to master after a failover or manually). It means
# that the eviction of keys will be just handled by the master, sending the
# DEL commands to the replica as keys evict in the master side.
#
# This behavior ensures that masters and replicas stay consistent, and is usually
# what you want, however if your replica is writable, or you want the replica
# to have a different memory setting, and you are sure all the writes performed
# to the replica are idempotent, then you may change this default (but be sure
# to understand what you are doing).
#
# Note that since the replica by default does not evict, it may end using more
# memory than the one set via maxmemory (there are certain buffers that may
# be larger on the replica, or data structures may sometimes take more memory
# and so forth). So make sure you monitor your replicas and make sure they
# have enough memory to never hit a real out-of-memory condition before the
# master hits the configured maxmemory setting.
#
# replica-ignore-maxmemory yes

# Redis reclaims expired keys in two ways: upon access when those keys are
# found to be expired, and also in background, in what is called the
# "active expire key". The key space is slowly and interactively scanned
# looking for expired keys to reclaim, so that it is possible to free memory
# of keys that are expired and will never be accessed again in a short time.
#
# The default effort of the expire cycle will try to avoid having more than
# ten percent of expired keys still in memory, and will try to avoid consuming
# more than 25% of total memory and to add latency to the system. However
# it is possible to increase the expire "effort" that is normally set to
# "1", to a greater value, up to the value "10". At its maximum value the
# system will use more CPU, longer cycles (and technically may introduce
# more latency), and will tollerate less already expired keys still present
# in the system. It's a tradeoff betweeen memory, CPU and latecy.
#
# active-expire-effort 1

############################# LAZY FREEING ####################################

# Redis has two primitives to delete keys. One is called DEL and is a blocking
# deletion of the object. It means that the server stops processing new commands
# in order to reclaim all the memory associated with an object in a synchronous
# way. If the key deleted is associated with a small object, the time needed
# in order to execute the DEL command is very small and comparable to most other
# O(1) or O(log_N) commands in Redis. However if the key is associated with an
# aggregated value containing millions of elements, the server can block for
# a long time (even seconds) in order to complete the operation.
#
# For the above reasons Redis also offers non blocking deletion primitives
# such as UNLINK (non blocking DEL) and the ASYNC option of FLUSHALL and
# FLUSHDB commands, in order to reclaim memory in background. Those commands
# are executed in constant time. Another thread will incrementally free the
# object in the background as fast as possible.
#
# DEL, UNLINK and ASYNC option of FLUSHALL and FLUSHDB are user-controlled.
# It's up to the design of the application to understand when it is a good
# idea to use one or the other. However the Redis server sometimes has to
# delete keys or flush the whole database as a side effect of other operations.
# Specifically Redis deletes objects independently of a user call in the
# following scenarios:
#
# 1) On eviction, because of the maxmemory and maxmemory policy configurations,
#    in order to make room for new data, without going over the specified
#    memory limit.
# 2) Because of expire: when a key with an associated time to live (see the
#    EXPIRE command) must be deleted from memory.
# 3) Because of a side effect of a command that stores data on a key that may
#    already exist. For example the RENAME command may delete the old key
#    content when it is replaced with another one. Similarly SUNIONSTORE
#    or SORT with STORE option may delete existing keys. The SET command
#    itself removes any old content of the specified key in order to replace
#    it with the specified string.
# 4) During replication, when a replica performs a full resynchronization with
#    its master, the content of the whole database is removed in order to
#    load the RDB file just transferred.
#
# In all the above cases the default is to delete objects in a blocking way,
# like if DEL was called. However you can configure each case specifically
# in order to instead release memory in a non-blocking way like if UNLINK
# was called, using the following configuration directives.

lazyfree-lazy-eviction no
lazyfree-lazy-expire no
lazyfree-lazy-server-del no
replica-lazy-flush no

# It is also possible, for the case when to replace the user code DEL calls
# with UNLINK calls is not easy, to modify the default behavior of the DEL
# command to act exactly like UNLINK, using the following configuration
# directive:

lazyfree-lazy-user-del no

################################ THREADED I/O #################################

# Redis is mostly single threaded, however there are certain threaded
# operations such as UNLINK, slow I/O accesses and other things that are
# performed on side threads.
#
# Now it is also possible to handle Redis clients socket reads and writes
# in different I/O threads. Since especially writing is so slow, normally
# Redis users use pipelining in order to speedup the Redis performances per
# core, and spawn multiple instances in order to scale more. Using I/O
# threads it is possible to easily speedup two times Redis without resorting
# to pipelining nor sharding of the instance.
#
# By default threading is disabled, we suggest enabling it only in machines
# that have at least 4 or more cores, leaving at least one spare core.
# Using more than 8 threads is unlikely to help much. We also recommend using
# threaded I/O only if you actually have performance problems, with Redis
# instances being able to use a quite big percentage of CPU time, otherwise
# there is no point in using this feature.
#
# So for instance if you have a four cores boxes, try to use 2 or 3 I/O
# threads, if you have a 8 cores, try to use 6 threads. In order to
# enable I/O threads use the following configuration directive:
#
# io-threads 4
#
# Setting io-threads to 1 will just use the main thread as usually.
# When I/O threads are enabled, we only use threads for writes, that is
# to thread the write(2) syscall and transfer the client buffers to the
# socket. However it is also possible to enable threading of reads and
# protocol parsing using the following configuration directive, by setting
# it to yes:
#
# io-threads-do-reads no
#
# Usually threading reads doesn't help much.
#
# NOTE 1: This configuration directive cannot be changed at runtime via
# CONFIG SET. Aso this feature currently does not work when SSL is
# enabled.
#
# NOTE 2: If you want to test the Redis speedup using redis-benchmark, make
# sure you also run the benchmark itself in threaded mode, using the
# --threads option to match the number of Redis theads, otherwise you'll not
# be able to notice the improvements.

############################## APPEND ONLY MODE ###############################

# By default Redis asynchronously dumps the dataset on disk. This mode is
# good enough in many applications, but an issue with the Redis process or
# a power outage may result into a few minutes of writes lost (depending on
# the configured save points).
#
# The Append Only File is an alternative persistence mode that provides
# much better durability. For instance using the default data fsync policy
# (see later in the config file) Redis can lose just one second of writes in a
# dramatic event like a server power outage, or a single write if something
# wrong with the Redis process itself happens, but the operating system is
# still running correctly.
#
# AOF and RDB persistence can be enabled at the same time without problems.
# If the AOF is enabled on startup Redis will load the AOF, that is the file
# with the better durability guarantees.
#
# Please check http://redis.io/topics/persistence for more information.

appendonly no

# The name of the append only file (default: "appendonly.aof")

appendfilename "appendonly-7000.aof"

# The fsync() call tells the Operating System to actually write data on disk
# instead of waiting for more data in the output buffer. Some OS will really flush
# data on disk, some other OS will just try to do it ASAP.
#
# Redis supports three different modes:
#
# no: don't fsync, just let the OS flush the data when it wants. Faster.
# always: fsync after every write to the append only log. Slow, Safest.
# everysec: fsync only one time every second. Compromise.
#
# The default is "everysec", as that's usually the right compromise between
# speed and data safety. It's up to you to understand if you can relax this to
# "no" that will let the operating system flush the output buffer when
# it wants, for better performances (but if you can live with the idea of
# some data loss consider the default persistence mode that's snapshotting),
# or on the contrary, use "always" that's very slow but a bit safer than
# everysec.
#
# More details please check the following article:
# http://antirez.com/post/redis-persistence-demystified.html
#
# If unsure, use "everysec".

# appendfsync always
appendfsync everysec
# appendfsync no

# When the AOF fsync policy is set to always or everysec, and a background
# saving process (a background save or AOF log background rewriting) is
# performing a lot of I/O against the disk, in some Linux configurations
# Redis may block too long on the fsync() call. Note that there is no fix for
# this currently, as even performing fsync in a different thread will block
# our synchronous write(2) call.
#
# In order to mitigate this problem it's possible to use the following option
# that will prevent fsync() from being called in the main process while a
# BGSAVE or BGREWRITEAOF is in progress.
#
# This means that while another child is saving, the durability of Redis is
# the same as "appendfsync none". In practical terms, this means that it is
# possible to lose up to 30 seconds of log in the worst scenario (with the
# default Linux settings).
#
# If you have latency problems turn this to "yes". Otherwise leave it as
# "no" that is the safest pick from the point of view of durability.

no-appendfsync-on-rewrite no

# Automatic rewrite of the append only file.
# Redis is able to automatically rewrite the log file implicitly calling
# BGREWRITEAOF when the AOF log size grows by the specified percentage.
#
# This is how it works: Redis remembers the size of the AOF file after the
# latest rewrite (if no rewrite has happened since the restart, the size of
# the AOF at startup is used).
#
# This base size is compared to the current size. If the current size is
# bigger than the specified percentage, the rewrite is triggered. Also
# you need to specify a minimal size for the AOF file to be rewritten, this
# is useful to avoid rewriting the AOF file even if the percentage increase
# is reached but it is still pretty small.
#
# Specify a percentage of zero in order to disable the automatic AOF
# rewrite feature.

auto-aof-rewrite-percentage 100
auto-aof-rewrite-min-size 64mb

# An AOF file may be found to be truncated at the end during the Redis
# startup process, when the AOF data gets loaded back into memory.
# This may happen when the system where Redis is running
# crashes, especially when an ext4 filesystem is mounted without the
# data=ordered option (however this can't happen when Redis itself
# crashes or aborts but the operating system still works correctly).
#
# Redis can either exit with an error when this happens, or load as much
# data as possible (the default now) and start if the AOF file is found
# to be truncated at the end. The following option controls this behavior.
#
# If aof-load-truncated is set to yes, a truncated AOF file is loaded and
# the Redis server starts emitting a log to inform the user of the event.
# Otherwise if the option is set to no, the server aborts with an error
# and refuses to start. When the option is set to no, the user requires
# to fix the AOF file using the "redis-check-aof" utility before to restart
# the server.
#
# Note that if the AOF file will be found to be corrupted in the middle
# the server will still exit with an error. This option only applies when
# Redis will try to read more data from the AOF file but not enough bytes
# will be found.
aof-load-truncated yes

# When rewriting the AOF file, Redis is able to use an RDB preamble in the
# AOF file for faster rewrites and recoveries. When this option is turned
# on the rewritten AOF file is composed of two different stanzas:
#
#   [RDB file][AOF tail]
#
# When loading Redis recognizes that the AOF file starts with the "REDIS"
# string and loads the prefixed RDB file, and continues loading the AOF
# tail.
aof-use-rdb-preamble yes

################################ LUA SCRIPTING  ###############################

# Max execution time of a Lua script in milliseconds.
#
# If the maximum execution time is reached Redis will log that a script is
# still in execution after the maximum allowed time and will start to
# reply to queries with an error.
#
# When a long running script exceeds the maximum execution time only the
# SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be
# used to stop a script that did not yet called write commands. The second
# is the only way to shut down the server in the case a write command was
# already issued by the script but the user doesn't want to wait for the natural
# termination of the script.
#
# Set it to 0 or a negative value for unlimited execution without warnings.
lua-time-limit 5000

################################ REDIS CLUSTER  ###############################

# Normal Redis instances can't be part of a Redis Cluster; only nodes that are
# started as cluster nodes can. In order to start a Redis instance as a
# cluster node enable the cluster support uncommenting the following:
#
 cluster-enabled yes

# Every cluster node has a cluster configuration file. This file is not
# intended to be edited by hand. It is created and updated by Redis nodes.
# Every Redis Cluster node requires a different cluster configuration file.
# Make sure that instances running in the same system do not have
# overlapping cluster configuration file names.
#
cluster-config-file nodes-7000.conf

# Cluster node timeout is the amount of milliseconds a node must be unreachable
# for it to be considered in failure state.
# Most other internal time limits are multiple of the node timeout.
#
 cluster-node-timeout 5000

# A replica of a failing master will avoid to start a failover if its data
# looks too old.
#
# There is no simple way for a replica to actually have an exact measure of
# its "data age", so the following two checks are performed:
#
# 1) If there are multiple replicas able to failover, they exchange messages
#    in order to try to give an advantage to the replica with the best
#    replication offset (more data from the master processed).
#    Replicas will try to get their rank by offset, and apply to the start
#    of the failover a delay proportional to their rank.
#
# 2) Every single replica computes the time of the last interaction with
#    its master. This can be the last ping or command received (if the master
#    is still in the "connected" state), or the time that elapsed since the
#    disconnection with the master (if the replication link is currently down).
#    If the last interaction is too old, the replica will not try to failover
#    at all.
#
# The point "2" can be tuned by user. Specifically a replica will not perform
# the failover if, since the last interaction with the master, the time
# elapsed is greater than:
#
#   (node-timeout * replica-validity-factor) + repl-ping-replica-period
#
# So for example if node-timeout is 30 seconds, and the replica-validity-factor
# is 10, and assuming a default repl-ping-replica-period of 10 seconds, the
# replica will not try to failover if it was not able to talk with the master
# for longer than 310 seconds.
#
# A large replica-validity-factor may allow replicas with too old data to failover
# a master, while a too small value may prevent the cluster from being able to
# elect a replica at all.
#
# For maximum availability, it is possible to set the replica-validity-factor
# to a value of 0, which means, that replicas will always try to failover the
# master regardless of the last time they interacted with the master.
# (However they'll always try to apply a delay proportional to their
# offset rank).
#
# Zero is the only value able to guarantee that when all the partitions heal
# the cluster will always be able to continue.
#
# cluster-replica-validity-factor 10

# Cluster replicas are able to migrate to orphaned masters, that are masters
# that are left without working replicas. This improves the cluster ability
# to resist to failures as otherwise an orphaned master can't be failed over
# in case of failure if it has no working replicas.
#
# Replicas migrate to orphaned masters only if there are still at least a
# given number of other working replicas for their old master. This number
# is the "migration barrier". A migration barrier of 1 means that a replica
# will migrate only if there is at least 1 other working replica for its master
# and so forth. It usually reflects the number of replicas you want for every
# master in your cluster.
#
# Default is 1 (replicas migrate only if their masters remain with at least
# one replica). To disable migration just set it to a very large value.
# A value of 0 can be set but is useful only for debugging and dangerous
# in production.
#
# cluster-migration-barrier 1

# By default Redis Cluster nodes stop accepting queries if they detect there
# is at least an hash slot uncovered (no available node is serving it).
# This way if the cluster is partially down (for example a range of hash slots
# are no longer covered) all the cluster becomes, eventually, unavailable.
# It automatically returns available as soon as all the slots are covered again.
#
# However sometimes you want the subset of the cluster which is working,
# to continue to accept queries for the part of the key space that is still
# covered. In order to do so, just set the cluster-require-full-coverage
# option to no.
#
# cluster-require-full-coverage yes

# This option, when set to yes, prevents replicas from trying to failover its
# master during master failures. However the master can still perform a
# manual failover, if forced to do so.
#
# This is useful in different scenarios, especially in the case of multiple
# data center operations, where we want one side to never be promoted if not
# in the case of a total DC failure.
#
# cluster-replica-no-failover no

# This option, when set to yes, allows nodes to serve read traffic while the
# the cluster is in a down state, as long as it believes it owns the slots.
#
# This is useful for two cases.  The first case is for when an application
# doesn't require consistency of data during node failures or network partitions.
# One example of this is a cache, where as long as the node has the data it
# should be able to serve it.
#
# The second use case is for configurations that don't meet the recommended
# three shards but want to enable cluster mode and scale later. A
# master outage in a 1 or 2 shard configuration causes a read/write outage to the
# entire cluster without this option set, with it set there is only a write outage.
# Without a quorum of masters, slot ownership will not change automatically.
#
# cluster-allow-reads-when-down no

# In order to setup your cluster make sure to read the documentation
# available at http://redis.io web site.

########################## CLUSTER DOCKER/NAT support  ########################

# In certain deployments, Redis Cluster nodes address discovery fails, because
# addresses are NAT-ted or because ports are forwarded (the typical case is
# Docker and other containers).
#
# In order to make Redis Cluster working in such environments, a static
# configuration where each node knows its public address is needed. The
# following two options are used for this scope, and are:
#
# * cluster-announce-ip
# * cluster-announce-port
# * cluster-announce-bus-port
#
# Each instruct the node about its address, client port, and cluster message
# bus port. The information is then published in the header of the bus packets
# so that other nodes will be able to correctly map the address of the node
# publishing the information.
#
# If the above options are not used, the normal Redis Cluster auto-detection
# will be used instead.
#
# Note that when remapped, the bus port may not be at the fixed offset of
# clients port + 10000, so you can specify any port and bus-port depending
# on how they get remapped. If the bus-port is not set, a fixed offset of
# 10000 will be used as usually.
#
# Example:
#
# cluster-announce-ip 10.1.1.5
# cluster-announce-port 6379
# cluster-announce-bus-port 6380

################################## SLOW LOG ###################################

# The Redis Slow Log is a system to log queries that exceeded a specified
# execution time. The execution time does not include the I/O operations
# like talking with the client, sending the reply and so forth,
# but just the time needed to actually execute the command (this is the only
# stage of command execution where the thread is blocked and can not serve
# other requests in the meantime).
#
# You can configure the slow log with two parameters: one tells Redis
# what is the execution time, in microseconds, to exceed in order for the
# command to get logged, and the other parameter is the length of the
# slow log. When a new command is logged the oldest one is removed from the
# queue of logged commands.

# The following time is expressed in microseconds, so 1000000 is equivalent
# to one second. Note that a negative number disables the slow log, while
# a value of zero forces the logging of every command.
slowlog-log-slower-than 10000

# There is no limit to this length. Just be aware that it will consume memory.
# You can reclaim memory used by the slow log with SLOWLOG RESET.
slowlog-max-len 128

################################ LATENCY MONITOR ##############################

# The Redis latency monitoring subsystem samples different operations
# at runtime in order to collect data related to possible sources of
# latency of a Redis instance.
#
# Via the LATENCY command this information is available to the user that can
# print graphs and obtain reports.
#
# The system only logs operations that were performed in a time equal or
# greater than the amount of milliseconds specified via the
# latency-monitor-threshold configuration directive. When its value is set
# to zero, the latency monitor is turned off.
#
# By default latency monitoring is disabled since it is mostly not needed
# if you don't have latency issues, and collecting data has a performance
# impact, that while very small, can be measured under big load. Latency
# monitoring can easily be enabled at runtime using the command
# "CONFIG SET latency-monitor-threshold <milliseconds>" if needed.
latency-monitor-threshold 0

############################# EVENT NOTIFICATION ##############################

# Redis can notify Pub/Sub clients about events happening in the key space.
# This feature is documented at http://redis.io/topics/notifications
#
# For instance if keyspace events notification is enabled, and a client
# performs a DEL operation on key "foo" stored in the Database 0, two
# messages will be published via Pub/Sub:
#
# PUBLISH __keyspace@0__:foo del
# PUBLISH __keyevent@0__:del foo
#
# It is possible to select the events that Redis will notify among a set
# of classes. Every class is identified by a single character:
#
#  K     Keyspace events, published with __keyspace@<db>__ prefix.
#  E     Keyevent events, published with __keyevent@<db>__ prefix.
#  g     Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ...
#  $     String commands
#  l     List commands
#  s     Set commands
#  h     Hash commands
#  z     Sorted set commands
#  x     Expired events (events generated every time a key expires)
#  e     Evicted events (events generated when a key is evicted for maxmemory)
#  t     Stream commands
#  m     Key-miss events (Note: It is not included in the 'A' class)
#  A     Alias for g$lshzxet, so that the "AKE" string means all the events
#        (Except key-miss events which are excluded from 'A' due to their
#         unique nature).
#
#  The "notify-keyspace-events" takes as argument a string that is composed
#  of zero or multiple characters. The empty string means that notifications
#  are disabled.
#
#  Example: to enable list and generic events, from the point of view of the
#           event name, use:
#
#  notify-keyspace-events Elg
#
#  Example 2: to get the stream of the expired keys subscribing to channel
#             name __keyevent@0__:expired use:
#
#  notify-keyspace-events Ex
#
#  By default all notifications are disabled because most users don't need
#  this feature and the feature has some overhead. Note that if you don't
#  specify at least one of K or E, no events will be delivered.
notify-keyspace-events ""

############################### GOPHER SERVER #################################

# Redis contains an implementation of the Gopher protocol, as specified in
# the RFC 1436 (https://www.ietf.org/rfc/rfc1436.txt).
#
# The Gopher protocol was very popular in the late '90s. It is an alternative
# to the web, and the implementation both server and client side is so simple
# that the Redis server has just 100 lines of code in order to implement this
# support.
#
# What do you do with Gopher nowadays? Well Gopher never *really* died, and
# lately there is a movement in order for the Gopher more hierarchical content
# composed of just plain text documents to be resurrected. Some want a simpler
# internet, others believe that the mainstream internet became too much
# controlled, and it's cool to create an alternative space for people that
# want a bit of fresh air.
#
# Anyway for the 10nth birthday of the Redis, we gave it the Gopher protocol
# as a gift.
#
# --- HOW IT WORKS? ---
#
# The Redis Gopher support uses the inline protocol of Redis, and specifically
# two kind of inline requests that were anyway illegal: an empty request
# or any request that starts with "/" (there are no Redis commands starting
# with such a slash). Normal RESP2/RESP3 requests are completely out of the
# path of the Gopher protocol implementation and are served as usually as well.
#
# If you open a connection to Redis when Gopher is enabled and send it
# a string like "/foo", if there is a key named "/foo" it is served via the
# Gopher protocol.
#
# In order to create a real Gopher "hole" (the name of a Gopher site in Gopher
# talking), you likely need a script like the following:
#
#   https://github.com/antirez/gopher2redis
#
# --- SECURITY WARNING ---
#
# If you plan to put Redis on the internet in a publicly accessible address
# to server Gopher pages MAKE SURE TO SET A PASSWORD to the instance.
# Once a password is set:
#
#   1. The Gopher server (when enabled, not by default) will still serve
#      content via Gopher.
#   2. However other commands cannot be called before the client will
#      authenticate.
#
# So use the 'requirepass' option to protect your instance.
#
# To enable Gopher support uncomment the following line and set
# the option from no (the default) to yes.
#
# gopher-enabled no

############################### ADVANCED CONFIG ###############################

# Hashes are encoded using a memory efficient data structure when they have a
# small number of entries, and the biggest entry does not exceed a given
# threshold. These thresholds can be configured using the following directives.
hash-max-ziplist-entries 512
hash-max-ziplist-value 64

# Lists are also encoded in a special way to save a lot of space.
# The number of entries allowed per internal list node can be specified
# as a fixed maximum size or a maximum number of elements.
# For a fixed maximum size, use -5 through -1, meaning:
# -5: max size: 64 Kb  <-- not recommended for normal workloads
# -4: max size: 32 Kb  <-- not recommended
# -3: max size: 16 Kb  <-- probably not recommended
# -2: max size: 8 Kb   <-- good
# -1: max size: 4 Kb   <-- good
# Positive numbers mean store up to _exactly_ that number of elements
# per list node.
# The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size),
# but if your use case is unique, adjust the settings as necessary.
list-max-ziplist-size -2

# Lists may also be compressed.
# Compress depth is the number of quicklist ziplist nodes from *each* side of
# the list to *exclude* from compression.  The head and tail of the list
# are always uncompressed for fast push/pop operations.  Settings are:
# 0: disable all list compression
# 1: depth 1 means "don't start compressing until after 1 node into the list,
#    going from either the head or tail"
#    So: [head]->node->node->...->node->[tail]
#    [head], [tail] will always be uncompressed; inner nodes will compress.
# 2: [head]->[next]->node->node->...->node->[prev]->[tail]
#    2 here means: don't compress head or head->next or tail->prev or tail,
#    but compress all nodes between them.
# 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail]
# etc.
list-compress-depth 0

# Sets have a special encoding in just one case: when a set is composed
# of just strings that happen to be integers in radix 10 in the range
# of 64 bit signed integers.
# The following configuration setting sets the limit in the size of the
# set in order to use this special memory saving encoding.
set-max-intset-entries 512

# Similarly to hashes and lists, sorted sets are also specially encoded in
# order to save a lot of space. This encoding is only used when the length and
# elements of a sorted set are below the following limits:
zset-max-ziplist-entries 128
zset-max-ziplist-value 64

# HyperLogLog sparse representation bytes limit. The limit includes the
# 16 bytes header. When an HyperLogLog using the sparse representation crosses
# this limit, it is converted into the dense representation.
#
# A value greater than 16000 is totally useless, since at that point the
# dense representation is more memory efficient.
#
# The suggested value is ~ 3000 in order to have the benefits of
# the space efficient encoding without slowing down too much PFADD,
# which is O(N) with the sparse encoding. The value can be raised to
# ~ 10000 when CPU is not a concern, but space is, and the data set is
# composed of many HyperLogLogs with cardinality in the 0 - 15000 range.
hll-sparse-max-bytes 3000

# Streams macro node max size / items. The stream data structure is a radix
# tree of big nodes that encode multiple items inside. Using this configuration
# it is possible to configure how big a single node can be in bytes, and the
# maximum number of items it may contain before switching to a new node when
# appending new stream entries. If any of the following settings are set to
# zero, the limit is ignored, so for instance it is possible to set just a
# max entires limit by setting max-bytes to 0 and max-entries to the desired
# value.
stream-node-max-bytes 4kb
stream-node-max-entries 100

# Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in
# order to help rehashing the main Redis hash table (the one mapping top-level
# keys to values). The hash table implementation Redis uses (see dict.c)
# performs a lazy rehashing: the more operation you run into a hash table
# that is rehashing, the more rehashing "steps" are performed, so if the
# server is idle the rehashing is never complete and some more memory is used
# by the hash table.
#
# The default is to use this millisecond 10 times every second in order to
# actively rehash the main dictionaries, freeing memory when possible.
#
# If unsure:
# use "activerehashing no" if you have hard latency requirements and it is
# not a good thing in your environment that Redis can reply from time to time
# to queries with 2 milliseconds delay.
#
# use "activerehashing yes" if you don't have such hard requirements but
# want to free memory asap when possible.
activerehashing yes

# The client output buffer limits can be used to force disconnection of clients
# that are not reading data from the server fast enough for some reason (a
# common reason is that a Pub/Sub client can't consume messages as fast as the
# publisher can produce them).
#
# The limit can be set differently for the three different classes of clients:
#
# normal -> normal clients including MONITOR clients
# replica  -> replica clients
# pubsub -> clients subscribed to at least one pubsub channel or pattern
#
# The syntax of every client-output-buffer-limit directive is the following:
#
# client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds>
#
# A client is immediately disconnected once the hard limit is reached, or if
# the soft limit is reached and remains reached for the specified number of
# seconds (continuously).
# So for instance if the hard limit is 32 megabytes and the soft limit is
# 16 megabytes / 10 seconds, the client will get disconnected immediately
# if the size of the output buffers reach 32 megabytes, but will also get
# disconnected if the client reaches 16 megabytes and continuously overcomes
# the limit for 10 seconds.
#
# By default normal clients are not limited because they don't receive data
# without asking (in a push way), but just after a request, so only
# asynchronous clients may create a scenario where data is requested faster
# than it can read.
#
# Instead there is a default limit for pubsub and replica clients, since
# subscribers and replicas receive data in a push fashion.
#
# Both the hard or the soft limit can be disabled by setting them to zero.
client-output-buffer-limit normal 0 0 0
client-output-buffer-limit replica 256mb 64mb 60
client-output-buffer-limit pubsub 32mb 8mb 60

# Client query buffers accumulate new commands. They are limited to a fixed
# amount by default in order to avoid that a protocol desynchronization (for
# instance due to a bug in the client) will lead to unbound memory usage in
# the query buffer. However you can configure it here if you have very special
# needs, such us huge multi/exec requests or alike.
#
# client-query-buffer-limit 1gb

# In the Redis protocol, bulk requests, that are, elements representing single
# strings, are normally limited ot 512 mb. However you can change this limit
# here.
#
# proto-max-bulk-len 512mb

# Redis calls an internal function to perform many background tasks, like
# closing connections of clients in timeout, purging expired keys that are
# never requested, and so forth.
#
# Not all tasks are performed with the same frequency, but Redis checks for
# tasks to perform according to the specified "hz" value.
#
# By default "hz" is set to 10. Raising the value will use more CPU when
# Redis is idle, but at the same time will make Redis more responsive when
# there are many keys expiring at the same time, and timeouts may be
# handled with more precision.
#
# The range is between 1 and 500, however a value over 100 is usually not
# a good idea. Most users should use the default of 10 and raise this up to
# 100 only in environments where very low latency is required.
hz 10

# Normally it is useful to have an HZ value which is proportional to the
# number of clients connected. This is useful in order, for instance, to
# avoid too many clients are processed for each background task invocation
# in order to avoid latency spikes.
#
# Since the default HZ value by default is conservatively set to 10, Redis
# offers, and enables by default, the ability to use an adaptive HZ value
# which will temporary raise when there are many connected clients.
#
# When dynamic HZ is enabled, the actual configured HZ will be used
# as a baseline, but multiples of the configured HZ value will be actually
# used as needed once more clients are connected. In this way an idle
# instance will use very little CPU time while a busy instance will be
# more responsive.
dynamic-hz yes

# When a child rewrites the AOF file, if the following option is enabled
# the file will be fsync-ed every 32 MB of data generated. This is useful
# in order to commit the file to the disk more incrementally and avoid
# big latency spikes.
aof-rewrite-incremental-fsync yes

# When redis saves RDB file, if the following option is enabled
# the file will be fsync-ed every 32 MB of data generated. This is useful
# in order to commit the file to the disk more incrementally and avoid
# big latency spikes.
rdb-save-incremental-fsync yes

# Redis LFU eviction (see maxmemory setting) can be tuned. However it is a good
# idea to start with the default settings and only change them after investigating
# how to improve the performances and how the keys LFU change over time, which
# is possible to inspect via the OBJECT FREQ command.
#
# There are two tunable parameters in the Redis LFU implementation: the
# counter logarithm factor and the counter decay time. It is important to
# understand what the two parameters mean before changing them.
#
# The LFU counter is just 8 bits per key, it's maximum value is 255, so Redis
# uses a probabilistic increment with logarithmic behavior. Given the value
# of the old counter, when a key is accessed, the counter is incremented in
# this way:
#
# 1. A random number R between 0 and 1 is extracted.
# 2. A probability P is calculated as 1/(old_value*lfu_log_factor+1).
# 3. The counter is incremented only if R < P.
#
# The default lfu-log-factor is 10. This is a table of how the frequency
# counter changes with a different number of accesses with different
# logarithmic factors:
#
# +--------+------------+------------+------------+------------+------------+
# | factor | 100 hits   | 1000 hits  | 100K hits  | 1M hits    | 10M hits   |
# +--------+------------+------------+------------+------------+------------+
# | 0      | 104        | 255        | 255        | 255        | 255        |
# +--------+------------+------------+------------+------------+------------+
# | 1      | 18         | 49         | 255        | 255        | 255        |
# +--------+------------+------------+------------+------------+------------+
# | 10     | 10         | 18         | 142        | 255        | 255        |
# +--------+------------+------------+------------+------------+------------+
# | 100    | 8          | 11         | 49         | 143        | 255        |
# +--------+------------+------------+------------+------------+------------+
#
# NOTE: The above table was obtained by running the following commands:
#
#   redis-benchmark -n 1000000 incr foo
#   redis-cli object freq foo
#
# NOTE 2: The counter initial value is 5 in order to give new objects a chance
# to accumulate hits.
#
# The counter decay time is the time, in minutes, that must elapse in order
# for the key counter to be divided by two (or decremented if it has a value
# less <= 10).
#
# The default value for the lfu-decay-time is 1. A Special value of 0 means to
# decay the counter every time it happens to be scanned.
#
# lfu-log-factor 10
# lfu-decay-time 1

########################### ACTIVE DEFRAGMENTATION #######################
#
# What is active defragmentation?
# -------------------------------
#
# Active (online) defragmentation allows a Redis server to compact the
# spaces left between small allocations and deallocations of data in memory,
# thus allowing to reclaim back memory.
#
# Fragmentation is a natural process that happens with every allocator (but
# less so with Jemalloc, fortunately) and certain workloads. Normally a server
# restart is needed in order to lower the fragmentation, or at least to flush
# away all the data and create it again. However thanks to this feature
# implemented by Oran Agra for Redis 4.0 this process can happen at runtime
# in an "hot" way, while the server is running.
#
# Basically when the fragmentation is over a certain level (see the
# configuration options below) Redis will start to create new copies of the
# values in contiguous memory regions by exploiting certain specific Jemalloc
# features (in order to understand if an allocation is causing fragmentation
# and to allocate it in a better place), and at the same time, will release the
# old copies of the data. This process, repeated incrementally for all the keys
# will cause the fragmentation to drop back to normal values.
#
# Important things to understand:
#
# 1. This feature is disabled by default, and only works if you compiled Redis
#    to use the copy of Jemalloc we ship with the source code of Redis.
#    This is the default with Linux builds.
#
# 2. You never need to enable this feature if you don't have fragmentation
#    issues.
#
# 3. Once you experience fragmentation, you can enable this feature when
#    needed with the command "CONFIG SET activedefrag yes".
#
# The configuration parameters are able to fine tune the behavior of the
# defragmentation process. If you are not sure about what they mean it is
# a good idea to leave the defaults untouched.

# Enabled active defragmentation
# activedefrag no

# Minimum amount of fragmentation waste to start active defrag
# active-defrag-ignore-bytes 100mb

# Minimum percentage of fragmentation to start active defrag
# active-defrag-threshold-lower 10

# Maximum percentage of fragmentation at which we use maximum effort
# active-defrag-threshold-upper 100

# Minimal effort for defrag in CPU percentage, to be used when the lower
# threshold is reached
# active-defrag-cycle-min 1

# Maximal effort for defrag in CPU percentage, to be used when the upper
# threshold is reached
# active-defrag-cycle-max 25

# Maximum number of set/hash/zset/list fields that will be processed from
# the main dictionary scan
# active-defrag-max-scan-fields 1000

# Jemalloc background thread for purging will be enabled by default
jemalloc-bg-thread yes

# It is possible to pin different threads and processes of Redis to specific
# CPUs in your system, in order to maximize the performances of the server.
# This is useful both in order to pin different Redis threads in different
# CPUs, but also in order to make sure that multiple Redis instances running
# in the same host will be pinned to different CPUs.
#
# Normally you can do this using the "taskset" command, however it is also
# possible to this via Redis configuration directly, both in Linux and FreeBSD.
#
# You can pin the server/IO threads, bio threads, aof rewrite child process, and
# the bgsave child process. The syntax to specify the cpu list is the same as
# the taskset command:
#
# Set redis server/io threads to cpu affinity 0,2,4,6:
# server_cpulist 0-7:2
#
# Set bio threads to cpu affinity 1,3:
# bio_cpulist 1,3
#
# Set aof rewrite child process to cpu affinity 8,9,10,11:
# aof_rewrite_cpulist 8-11
#
# Set bgsave child process to cpu affinity 1,10,11
# bgsave_cpulist 1,10-11
# Generated by CONFIG REWRITE
user default on nopass ~* +@all

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

635

636

637

638

639

640

641

642

643

644

645

646

647

648

649

650

651

652

653

654

655

656

657

658

659

660

661

662

663

664

665

666

667

668

669

670

671

672

673

674

675

676

677

678

679

680

681

682

683

684

685

686

687

688

689

690

691

692

693

694

695

696

697

698

699

700

701

702

703

704

705

706

707

708

709

710

711

712

713

714

715

716

717

718

719

720

721

722

723

724

725

726

727

728

729

730

731

732

733

734

735

736

737

738

739

740

741

742

743

744

745

746

747

748

749

750

751

752

753

754

755

756

757

758

759

760

761

762

763

764

765

766

767

768

769

770

771

772

773

774

775

776

777

778

779

780

781

782

783

784

785

786

787

788

789

790

791

792

793

794

795

796

797

798

799

800

801

802

803

804

805

806

807

808

809

810

811

812

813

814

815

816

817

818

819

820

821

822

823

824

825

826

827

828

829

830

831

832

833

834

835

836

837

838

839

840

841

842

843

844

845

846

847

848

849

850

851

852

853

854

855

856

857

858

859

860

861

862

863

864

865

866

867

868

869

870

871

872

873

874

875

876

877

878

879

880

881

882

883

884

885

886

887

888

889

890

891

892

893

894

895

896

897

898

899

900

901

902

903

904

905

906

907

908

909

910

911

912

913

914

915

916

917

918

919

920

921

922

923

924

925

926

927

928

929

930

931

932

933

934

935

936

937

938

939

940

941

942

943

944

945

946

947

948

949

950

951

952

953

954

955

956

957

958

959

960

961

962

963

964

965

966

967

968

969

970

971

972

973

974

975

976

977

978

979

980

981

982

983

984

985

986

987

988

989

990

991

992

993

994

995

996

997

998

999

1000

1001

1002

1003

1004

1005

1006

1007

1008

1009

1010

1011

1012

1013

1014

1015

1016

1017

1018

1019

1020

1021

1022

1023

1024

1025

1026

1027

1028

1029

1030

1031

1032

1033

1034

1035

1036

1037

1038

1039

1040

1041

1042

1043

1044

1045

1046

1047

1048

1049

1050

1051

1052

1053

1054

1055

1056

1057

1058

1059

1060

1061

1062

1063

1064

1065

1066

1067

1068

1069

1070

1071

1072

1073

1074

1075

1076

1077

1078

1079

1080

1081

1082

1083

1084

1085

1086

1087

1088

1089

1090

1091

1092

1093

1094

1095

1096

1097

1098

1099

1100

1101

1102

1103

1104

1105

1106

1107

1108

1109

1110

1111

1112

1113

1114

1115

1116

1117

1118

1119

1120

1121

1122

1123

1124

1125

1126

1127

1128

1129

1130

1131

1132

1133

1134

1135

1136

1137

1138

1139

1140

1141

1142

1143

1144

1145

1146

1147

1148

1149

1150

1151

1152

1153

1154

1155

1156

1157

1158

1159

1160

1161

1162

1163

1164

1165

1166

1167

1168

1169

1170

1171

1172

1173

1174

1175

1176

1177

1178

1179

1180

1181

1182

1183

1184

1185

1186

1187

1188

1189

1190

1191

1192

1193

1194

1195

1196

1197

1198

1199

1200

1201

1202

1203

1204

1205

1206

1207

1208

1209

1210

1211

1212

1213

1214

1215

1216

1217

1218

1219

1220

1221

1222

1223

1224

1225

1226

1227

1228

1229

1230

1231

1232

1233

1234

1235

1236

1237

1238

1239

1240

1241

1242

1243

1244

1245

1246

1247

1248

1249

1250

1251

1252

1253

1254

1255

1256

1257

1258

1259

1260

1261

1262

1263

1264

1265

1266

1267

1268

1269

1270

1271

1272

1273

1274

1275

1276

1277

1278

1279

1280

1281

1282

1283

1284

1285

1286

1287

1288

1289

1290

1291

1292

1293

1294

1295

1296

1297

1298

1299

1300

1301

1302

1303

1304

1305

1306

1307

1308

1309

1310

1311

1312

1313

1314

1315

1316

1317

1318

1319

1320

1321

1322

1323

1324

1325

1326

1327

1328

1329

1330

1331

1332

1333

1334

1335

1336

1337

1338

1339

1340

1341

1342

1343

1344

1345

1346

1347

1348

1349

1350

1351

1352

1353

1354

1355

1356

1357

1358

1359

1360

1361

1362

1363

1364

1365

1366

1367

1368

1369

1370

1371

1372

1373

1374

1375

1376

1377

1378

1379

1380

1381

1382

1383

1384

1385

1386

1387

1388

1389

1390

1391

1392

1393

1394

1395

1396

1397

1398

1399

1400

1401

1402

1403

1404

1405

1406

1407

1408

1409

1410

1411

1412

1413

1414

1415

1416

1417

1418

1419

1420

1421

1422

1423

1424

1425

1426

1427

1428

1429

1430

1431

1432

1433

1434

1435

1436

1437

1438

1439

1440

1441

1442

1443

1444

1445

1446

1447

1448

1449

1450

1451

1452

1453

1454

1455

1456

1457

1458

1459

1460

1461

1462

1463

1464

1465

1466

1467

1468

1469

1470

1471

1472

1473

1474

1475

1476

1477

1478

1479

1480

1481

1482

1483

1484

1485

1486

1487

1488

1489

1490

1491

1492

1493

1494

1495

1496

1497

1498

1499

1500

1501

1502

1503

1504

1505

1506

1507

1508

1509

1510

1511

1512

1513

1514

1515

1516

1517

1518

1519

1520

1521

1522

1523

1524

1525

1526

1527

1528

1529

1530

1531

1532

1533

1534

1535

1536

1537

1538

1539

1540

1541

1542

1543

1544

1545

1546

1547

1548

1549

1550

1551

1552

1553

1554

1555

1556

1557

1558

1559

1560

1561

1562

1563

1564

1565

1566

1567

1568

1569

1570

1571

1572

1573

1574

1575

1576

1577

1578

1579

1580

1581

1582

1583

1584

1585

1586

1587

1588

1589

1590

1591

1592

1593

1594

1595

1596

1597

1598

1599

1600

1601

1602

1603

1604

1605

1606

1607

1608

1609

1610

1611

1612

1613

1614

1615

1616

1617

1618

1619

1620

1621

1622

1623

1624

1625

1626

1627

1628

1629

1630

1631

1632

1633

1634

1635

1636

1637

1638

1639

1640

1641

1642

1643

1644

1645

1646

1647

1648

1649

1650

1651

1652

1653

1654

1655

1656

1657

1658

1659

1660

1661

1662

1663

1664

1665

1666

1667

1668

1669

1670

1671

1672

1673

1674

1675

1676

1677

1678

1679

1680

1681

1682

1683

1684

1685

1686

1687

1688

1689

1690

1691

1692

1693

1694

1695

1696

1697

1698

1699

1700

1701

1702

1703

1704

1705

1706

1707

1708

1709

1710

1711

1712

1713

1714

1715

1716

1717

1718

1719

1720

1721

1722

1723

1724

1725

1726

1727

1728

1729

1730

1731

1732

1733

1734

1735

1736

1737

1738

1739

1740

1741

1742

1743

1744

1745

1746

1747

1748

1749

1750

1751

1752

1753

1754

1755

1756

1757

1758

1759

1760

1761

1762

1763

1764

1765

1766

1767

1768

1769

1770

1771

1772

1773

1774

1775

1776

1777

1778

1779

1780

1781

1782

1783

1784

1785

1786

1787

1788

1789

1790

1791

1792

1793

1794

1795

1796

1797

1798

1799

1800

1801

1802

1803

1804

1805

1806

1807

1808

1809

1810

1811

1812

1813

1814

1815

1816

1817

1818

1819

1820

1821

1822

1823

1824

1825

1826

1827

1828

1829

1830

1831

1832

1833

1834

1835

1836

# Redis configuration file example.

# Note that in order to read the configuration file, Redis must be

# started with the file path as first argument:

# ./redis-server /path/to/redis.conf

# Note on units: when memory size is needed, it is possible to specify

# it in the usual form of 1k 5GB 4M and so forth:

# 1k => 1000 bytes

# 1kb => 1024 bytes

# 1m => 1000000 bytes

# 1mb => 1024*1024 bytes

# 1g => 1000000000 bytes

# 1gb => 1024*1024*1024 bytes

# units are case insensitive so 1GB 1Gb 1gB are all the same.

################################## INCLUDES ###################################

# Include one or more other config files here. This is useful if you

# have a standard template that goes to all Redis servers but also need

# to customize a few per-server settings. Include files can include

# other files, so use this wisely.

# Notice option "include" won't be rewritten by command "CONFIG REWRITE"

# from admin or Redis Sentinel. Since Redis always uses the last processed

# line as value of a configuration directive, you'd better put includes

# at the beginning of this file to avoid overwriting config change at runtime.

# If instead you are interested in using includes to override configuration

# options, it is better to use include as the last line.

# include /path/to/local.conf

# include /path/to/other.conf

################################## MODULES #####################################

# Load modules at startup. If the server is not able to load modules

# it will abort. It is possible to use multiple loadmodule directives.

# loadmodule /path/to/my_module.so

# loadmodule /path/to/other_module.so

################################## NETWORK #####################################

# By default, if no "bind" configuration directive is specified, Redis listens

# for connections from all the network interfaces available on the server.

# It is possible to listen to just one or multiple selected interfaces using

# the "bind" configuration directive, followed by one or more IP addresses.

# Examples:

# bind 192.168.1.100 10.0.0.1

# bind 127.0.0.1 ::1

# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the

# internet, binding to all the interfaces is dangerous and will expose the

# instance to everybody on the internet. So by default we uncomment the

# following bind directive, that will force Redis to listen only into

# the IPv4 loopback interface address (this means Redis will be able to

# accept connections only from clients running into the same computer it

# is running).

# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES

# JUST COMMENT THE FOLLOWING LINE.

# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

bind 0.0.0.0

# Protected mode is a layer of security protection, in order to avoid that

# Redis instances left open on the internet are accessed and exploited.

# When protected mode is on and if:

# 1) The server is not binding explicitly to a set of addresses using the

# "bind" directive.

# 2) No password is configured.

# The server only accepts connections from clients connecting from the

# IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from Unix domain

# sockets.

# By default protected mode is enabled. You should disable it only if

# you are sure you want clients from other hosts to connect to Redis

# even if no authentication is configured, nor a specific set of interfaces

# are explicitly listed using the "bind" directive.

protected-mode no

# Accept connections on the specified port, default is 6379 (IANA #815344).

# If port 0 is specified Redis will not listen on a TCP socket.

port 7000

# TCP listen() backlog.

# In high requests-per-second environments you need an high backlog in order

# to avoid slow clients connections issues. Note that the Linux kernel

# will silently truncate it to the value of /proc/sys/net/core/somaxconn so

# make sure to raise both the value of somaxconn and tcp_max_syn_backlog

# in order to get the desired effect.

tcp-backlog 511

# Unix socket.

# Specify the path for the Unix socket that will be used to listen for

# incoming connections. There is no default, so Redis will not listen

# on a unix socket when not specified.

# unixsocket /tmp/redis.sock

# unixsocketperm 700

# Close the connection after a client is idle for N seconds (0 to disable)

timeout 0

# TCP keepalive.

# If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence

# of communication. This is useful for two reasons:

# 1) Detect dead peers.

# 2) Take the connection alive from the point of view of network

# equipment in the middle.

# On Linux, the specified value (in seconds) is the period used to send ACKs.

# Note that to close the connection the double of the time is needed.

# On other kernels the period depends on the kernel configuration.

# A reasonable value for this option is 300 seconds, which is the new

# Redis default starting with Redis 3.2.1.

tcp-keepalive 300

################################# TLS/SSL #####################################

# By default, TLS/SSL is disabled. To enable it, the "tls-port" configuration

# directive can be used to define TLS-listening ports. To enable TLS on the

# default port, use:

# port 0

# tls-port 6379

# Configure a X.509 certificate and private key to use for authenticating the

# server to connected clients, masters or cluster peers. These files should be

# PEM formatted.

# tls-cert-file redis.crt

# tls-key-file redis.key

# Configure a DH parameters file to enable Diffie-Hellman (DH) key exchange:

# tls-dh-params-file redis.dh

# Configure a CA certificate(s) bundle or directory to authenticate TLS/SSL

# clients and peers. Redis requires an explicit configuration of at least one

# of these, and will not implicitly use the system wide configuration.

# tls-ca-cert-file ca.crt

# tls-ca-cert-dir /etc/ssl/certs

# By default, clients (including replica servers) on a TLS port are required

# to authenticate using valid client side certificates.

# It is possible to disable authentication using this directive.

# tls-auth-clients no

# By default, a Redis replica does not attempt to establish a TLS connection

# with its master.

# Use the following directive to enable TLS on replication links.

# tls-replication yes

# By default, the Redis Cluster bus uses a plain TCP connection. To enable

# TLS for the bus protocol, use the following directive:

# tls-cluster yes

# Explicitly specify TLS versions to support. Allowed values are case insensitive

# and include "TLSv1", "TLSv1.1", "TLSv1.2", "TLSv1.3" (OpenSSL >= 1.1.1) or

# any combination. To enable only TLSv1.2 and TLSv1.3, use:

# tls-protocols "TLSv1.2 TLSv1.3"

# Configure allowed ciphers. See the ciphers(1ssl) manpage for more information

# about the syntax of this string.

# Note: this configuration applies only to <= TLSv1.2.

# tls-ciphers DEFAULT:!MEDIUM

# Configure allowed TLSv1.3 ciphersuites. See the ciphers(1ssl) manpage for more

# information about the syntax of this string, and specifically for TLSv1.3

# ciphersuites.

# tls-ciphersuites TLS_CHACHA20_POLY1305_SHA256

# When choosing a cipher, use the server's preference instead of the client

# preference. By default, the server follows the client's preference.

# tls-prefer-server-ciphers yes

# By default, TLS session caching is enabled to allow faster and less expensive

# reconnections by clients that support it. Use the following directive to disable

# caching.

# tls-session-caching no

# Change the default number of TLS sessions cached. A zero value sets the cache

# to unlimited size. The default size is 20480.

# tls-session-cache-size 5000

# Change the default timeout of cached TLS sessions. The default timeout is 300

# seconds.

# tls-session-cache-timeout 60

################################# GENERAL #####################################

# By default Redis does not run as a daemon. Use 'yes' if you need it.

# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.

daemonize yes

# If you run Redis from upstart or systemd, Redis can interact with your

# supervision tree. Options:

# supervised no - no supervision interaction

# supervised upstart - signal upstart by putting Redis into SIGSTOP mode

# supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET

# supervised auto - detect upstart or systemd method based on

# UPSTART_JOB or NOTIFY_SOCKET environment variables

# Note: these supervision methods only signal "process is ready."

# They do not enable continuous liveness pings back to your supervisor.

supervised no

# If a pid file is specified, Redis writes it where specified at startup

# and removes it at exit.

# When the server runs non daemonized, no pid file is created if none is

# specified in the configuration. When the server is daemonized, the pid file

# is used even if not specified, defaulting to "/var/run/redis.pid".

# Creating a pid file is best effort: if Redis is not able to create it

# nothing bad happens, the server will start and run normally.

pidfile "/var/run/redis_6379.pid"

# Specify the server verbosity level.

# This can be one of:

# debug (a lot of information, useful for development/testing)

# verbose (many rarely useful info, but not a mess like the debug level)

# notice (moderately verbose, what you want in production probably)

# warning (only very important / critical messages are logged)

loglevel notice

# Specify the log file name. Also the empty string can be used to force

# Redis to log on the standard output. Note that if you use standard

# output for logging but daemonize, logs will be sent to /dev/null

logfile ""

# To enable logging to the system logger, just set 'syslog-enabled' to yes,

# and optionally update the other syslog parameters to suit your needs.

# syslog-enabled no

# Specify the syslog identity.

# syslog-ident redis

# Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.

# syslog-facility local0

# Set the number of databases. The default database is DB 0, you can select

# a different one on a per-connection basis using SELECT <dbid> where

# dbid is a number between 0 and 'databases'-1

databases 16

# By default Redis shows an ASCII art logo only when started to log to the

# standard output and if the standard output is a TTY. Basically this means

# that normally a logo is displayed only in interactive sessions.

# However it is possible to force the pre-4.0 behavior and always show a

# ASCII art logo in startup logs by setting the following option to yes.

always-show-logo yes

################################ SNAPSHOTTING ################################

# Save the DB on disk:

# save <seconds> <changes>

# Will save the DB if both the given number of seconds and the given

# number of write operations against the DB occurred.

# In the example below the behaviour will be to save:

# after 900 sec (15 min) if at least 1 key changed

# after 300 sec (5 min) if at least 10 keys changed

# after 60 sec if at least 10000 keys changed

# Note: you can disable saving completely by commenting out all "save" lines.

# It is also possible to remove all the previously configured save

# points by adding a save directive with a single empty string argument

# like in the following example:

# save ""

save 900 1

save 300 10

save 60 10000

# By default Redis will stop accepting writes if RDB snapshots are enabled

# (at least one save point) and the latest background save failed.

# This will make the user aware (in a hard way) that data is not persisting

# on disk properly, otherwise chances are that no one will notice and some

# disaster will happen.

# If the background saving process will start working again Redis will

# automatically allow writes again.

# However if you have setup your proper monitoring of the Redis server

# and persistence, you may want to disable this feature so that Redis will

# continue to work as usual even if there are problems with disk,

# permissions, and so forth.

stop-writes-on-bgsave-error yes

# Compress string objects using LZF when dump .rdb databases?

# For default that's set to 'yes' as it's almost always a win.

# If you want to save some CPU in the saving child set it to 'no' but

# the dataset will likely be bigger if you have compressible values or keys.

rdbcompression yes

# Since version 5 of RDB a CRC64 checksum is placed at the end of the file.

# This makes the format more resistant to corruption but there is a performance

# hit to pay (around 10%) when saving and loading RDB files, so you can disable it

# for maximum performances.

# RDB files created with checksum disabled have a checksum of zero that will

# tell the loading code to skip the check.

rdbchecksum yes

# The filename where to dump the DB

dbfilename "dump-7000.rdb"

# Remove RDB files used by replication in instances without persistence

# enabled. By default this option is disabled, however there are environments

# where for regulations or other security concerns, RDB files persisted on

# disk by masters in order to feed replicas, or stored on disk by replicas

# in order to load them for the initial synchronization, should be deleted

# ASAP. Note that this option ONLY WORKS in instances that have both AOF

# and RDB persistence disabled, otherwise is completely ignored.

# An alternative (and sometimes better) way to obtain the same effect is

# to use diskless replication on both master and replicas instances. However

# in the case of replicas, diskless is not always an option.

rdb-del-sync-files no

# The working directory.

# The DB will be written inside this directory, with the filename specified

# above using the 'dbfilename' configuration directive.

# The Append Only File will also be created inside this directory.

# Note that you must specify a directory here, not a file name.

dir "/mnt/7000"

################################# REPLICATION #################################

# Master-Replica replication. Use replicaof to make a Redis instance a copy of

# another Redis server. A few things to understand ASAP about Redis replication.

# +------------------+ +---------------+

# | Master | ---> | Replica |

# | (receive writes) | | (exact copy) |

# +------------------+ +---------------+

# 1) Redis replication is asynchronous, but you can configure a master to

# stop accepting writes if it appears to be not connected with at least

# a given number of replicas.

# 2) Redis replicas are able to perform a partial resynchronization with the

# master if the replication link is lost for a relatively small amount of

# time. You may want to configure the replication backlog size (see the next

# sections of this file) with a sensible value depending on your needs.

# 3) Replication is automatic and does not need user intervention. After a

# network partition replicas automatically try to reconnect to masters

# and resynchronize with them.

# replicaof <masterip> <masterport>

# If the master is password protected (using the "requirepass" configuration

# directive below) it is possible to tell the replica to authenticate before

# starting the replication synchronization process, otherwise the master will

# refuse the replica request.

# masterauth <master-password>

# However this is not enough if you are using Redis ACLs (for Redis version

# 6 or greater), and the default user is not capable of running the PSYNC

# command and/or other commands needed for replication. In this case it's

# better to configure a special user to use with replication, and specify the

# masteruser configuration as such:

# masteruser <username>

# When masteruser is specified, the replica will authenticate against its

# master using the new AUTH form: AUTH <username> <password>.

# When a replica loses its connection with the master, or when the replication

# is still in progress, the replica can act in two different ways:

# 1) if replica-serve-stale-data is set to 'yes' (the default) the replica will

# still reply to client requests, possibly with out of date data, or the

# data set may just be empty if this is the first synchronization.

# 2) if replica-serve-stale-data is set to 'no' the replica will reply with

# an error "SYNC with master in progress" to all the kind of commands

# but to INFO, replicaOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG,

# SUBSCRIBE, UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, PUBLISH, PUBSUB,

# COMMAND, POST, HOST: and LATENCY.

replica-serve-stale-data yes

# You can configure a replica instance to accept writes or not. Writing against

# a replica instance may be useful to store some ephemeral data (because data

# written on a replica will be easily deleted after resync with the master) but

# may also cause problems if clients are writing to it because of a

# misconfiguration.

# Since Redis 2.6 by default replicas are read-only.

# Note: read only replicas are not designed to be exposed to untrusted clients

# on the internet. It's just a protection layer against misuse of the instance.

# Still a read only replica exports by default all the administrative commands

# such as CONFIG, DEBUG, and so forth. To a limited extent you can improve

# security of read only replicas using 'rename-command' to shadow all the

# administrative / dangerous commands.

replica-read-only yes

# Replication SYNC strategy: disk or socket.

# New replicas and reconnecting replicas that are not able to continue the

# replication process just receiving differences, need to do what is called a

# "full synchronization". An RDB file is transmitted from the master to the

# replicas.

# The transmission can happen in two different ways:

# 1) Disk-backed: The Redis master creates a new process that writes the RDB

# file on disk. Later the file is transferred by the parent

# process to the replicas incrementally.

# 2) Diskless: The Redis master creates a new process that directly writes the

# RDB file to replica sockets, without touching the disk at all.

# With disk-backed replication, while the RDB file is generated, more replicas

# can be queued and served with the RDB file as soon as the current child

# producing the RDB file finishes its work. With diskless replication instead

# once the transfer starts, new replicas arriving will be queued and a new

# transfer will start when the current one terminates.

# When diskless replication is used, the master waits a configurable amount of

# time (in seconds) before starting the transfer in the hope that multiple

# replicas will arrive and the transfer can be parallelized.

# With slow disks and fast (large bandwidth) networks, diskless replication

# works better.

repl-diskless-sync no

# When diskless replication is enabled, it is possible to configure the delay

# the server waits in order to spawn the child that transfers the RDB via socket

# to the replicas.

# This is important since once the transfer starts, it is not possible to serve

# new replicas arriving, that will be queued for the next RDB transfer, so the

# server waits a delay in order to let more replicas arrive.

# The delay is specified in seconds, and by default is 5 seconds. To disable

# it entirely just set it to 0 seconds and the transfer will start ASAP.

repl-diskless-sync-delay 5

# -----------------------------------------------------------------------------

# WARNING: RDB diskless load is experimental. Since in this setup the replica

# does not immediately store an RDB on disk, it may cause data loss during

# failovers. RDB diskless load + Redis modules not handling I/O reads may also

# cause Redis to abort in case of I/O errors during the initial synchronization

# stage with the master. Use only if your do what you are doing.

# -----------------------------------------------------------------------------

# Replica can load the RDB it reads from the replication link directly from the

# socket, or store the RDB to a file and read that file after it was completely

# recived from the master.

# In many cases the disk is slower than the network, and storing and loading

# the RDB file may increase replication time (and even increase the master's

# Copy on Write memory and salve buffers).

# However, parsing the RDB file directly from the socket may mean that we have

# to flush the contents of the current database before the full rdb was

# received. For this reason we have the following options:

# "disabled" - Don't use diskless load (store the rdb file to the disk first)

# "on-empty-db" - Use diskless load only when it is completely safe.

# "swapdb" - Keep a copy of the current db contents in RAM while parsing

# the data directly from the socket. note that this requires

# sufficient memory, if you don't have it, you risk an OOM kill.

repl-diskless-load disabled

# Replicas send PINGs to server in a predefined interval. It's possible to

# change this interval with the repl_ping_replica_period option. The default

# value is 10 seconds.

# repl-ping-replica-period 10

# The following option sets the replication timeout for:

# 1) Bulk transfer I/O during SYNC, from the point of view of replica.

# 2) Master timeout from the point of view of replicas (data, pings).

# 3) Replica timeout from the point of view of masters (REPLCONF ACK pings).

# It is important to make sure that this value is greater than the value

# specified for repl-ping-replica-period otherwise a timeout will be detected

# every time there is low traffic between the master and the replica.

# repl-timeout 60

# Disable TCP_NODELAY on the replica socket after SYNC?

# If you select "yes" Redis will use a smaller number of TCP packets and

# less bandwidth to send data to replicas. But this can add a delay for

# the data to appear on the replica side, up to 40 milliseconds with

# Linux kernels using a default configuration.

# If you select "no" the delay for data to appear on the replica side will

# be reduced but more bandwidth will be used for replication.

# By default we optimize for low latency, but in very high traffic conditions

# or when the master and replicas are many hops away, turning this to "yes" may

# be a good idea.

repl-disable-tcp-nodelay no

# Set the replication backlog size. The backlog is a buffer that accumulates

# replica data when replicas are disconnected for some time, so that when a

# replica wants to reconnect again, often a full resync is not needed, but a

# partial resync is enough, just passing the portion of data the replica

# missed while disconnected.

# The bigger the replication backlog, the longer the time the replica can be

# disconnected and later be able to perform a partial resynchronization.

# The backlog is only allocated once there is at least a replica connected.

# repl-backlog-size 1mb

# After a master has no longer connected replicas for some time, the backlog

# will be freed. The following option configures the amount of seconds that

# need to elapse, starting from the time the last replica disconnected, for

# the backlog buffer to be freed.

# Note that replicas never free the backlog for timeout, since they may be

# promoted to masters later, and should be able to correctly "partially

# resynchronize" with the replicas: hence they should always accumulate backlog.

# A value of 0 means to never release the backlog.

# repl-backlog-ttl 3600

# The replica priority is an integer number published by Redis in the INFO

# output. It is used by Redis Sentinel in order to select a replica to promote

# into a master if the master is no longer working correctly.

# A replica with a low priority number is considered better for promotion, so

# for instance if there are three replicas with priority 10, 100, 25 Sentinel

# will pick the one with priority 10, that is the lowest.

# However a special priority of 0 marks the replica as not able to perform the

# role of master, so a replica with priority of 0 will never be selected by

# Redis Sentinel for promotion.

# By default the priority is 100.

replica-priority 100

# It is possible for a master to stop accepting writes if there are less than

# N replicas connected, having a lag less or equal than M seconds.

# The N replicas need to be in "online" state.

# The lag in seconds, that must be <= the specified value, is calculated from

# the last ping received from the replica, that is usually sent every second.

# This option does not GUARANTEE that N replicas will accept the write, but

# will limit the window of exposure for lost writes in case not enough replicas

# are available, to the specified number of seconds.

# For example to require at least 3 replicas with a lag <= 10 seconds use:

# min-replicas-to-write 3

# min-replicas-max-lag 10

# Setting one or the other to 0 disables the feature.

# By default min-replicas-to-write is set to 0 (feature disabled) and

# min-replicas-max-lag is set to 10.

# A Redis master is able to list the address and port of the attached

# replicas in different ways. For example the "INFO replication" section

# offers this information, which is used, among other tools, by

# Redis Sentinel in order to discover replica instances.

# Another place where this info is available is in the output of the

# "ROLE" command of a master.

# The listed IP and address normally reported by a replica is obtained

# in the following way:

# IP: The address is auto detected by checking the peer address

# of the socket used by the replica to connect with the master.

# Port: The port is communicated by the replica during the replication

# handshake, and is normally the port that the replica is using to

# listen for connections.

# However when port forwarding or Network Address Translation (NAT) is

# used, the replica may be actually reachable via different IP and port

# pairs. The following two options can be used by a replica in order to

# report to its master a specific set of IP and port, so that both INFO

# and ROLE will report those values.

# There is no need to use both the options if you need to override just

# the port or the IP address.

# replica-announce-ip 5.5.5.5

# replica-announce-port 1234

############################### KEYS TRACKING #################################

# Redis implements server assisted support for client side caching of values.

# This is implemented using an invalidation table that remembers, using

# 16 millions of slots, what clients may have certain subsets of keys. In turn

# this is used in order to send invalidation messages to clients. Please

# to understand more about the feature check this page:

# https://redis.io/topics/client-side-caching

# When tracking is enabled for a client, all the read only queries are assumed

# to be cached: this will force Redis to store information in the invalidation

# table. When keys are modified, such information is flushed away, and

# invalidation messages are sent to the clients. However if the workload is

# heavily dominated by reads, Redis could use more and more memory in order

# to track the keys fetched by many clients.

# For this reason it is possible to configure a maximum fill value for the

# invalidation table. By default it is set to 1M of keys, and once this limit

# is reached, Redis will start to evict keys in the invalidation table

# even if they were not modified, just to reclaim memory: this will in turn

# force the clients to invalidate the cached values. Basically the table

# maximum size is a trade off between the memory you want to spend server

# side to track information about who cached what, and the ability of clients

# to retain cached objects in memory.

# If you set the value to 0, it means there are no limits, and Redis will

# retain as many keys as needed in the invalidation table.

# In the "stats" INFO section, you can find information about the number of

# keys in the invalidation table at every given moment.

# Note: when key tracking is used in broadcasting mode, no memory is used

# in the server side so this setting is useless.

# tracking-table-max-keys 1000000

################################## SECURITY ###################################

# Warning: since Redis is pretty fast an outside user can try up to

# 1 million passwords per second against a modern box. This means that you

# should use very strong passwords, otherwise they will be very easy to break.

# Note that because the password is really a shared secret between the client

# and the server, and should not be memorized by any human, the password

# can be easily a long string from /dev/urandom or whatever, so by using a

# long and unguessable password no brute force attack will be possible.

# Redis ACL users are defined in the following format:

# user <username> ... acl rules ...

# For example:

# user worker +@list +@connection ~jobs:* on >ffa9203c493aa99

# The special username "default" is used for new connections. If this user

# has the "nopass" rule, then new connections will be immediately authenticated

# as the "default" user without the need of any password provided via the

# AUTH command. Otherwise if the "default" user is not flagged with "nopass"

# the connections will start in not authenticated state, and will require

# AUTH (or the HELLO command AUTH option) in order to be authenticated and

# start to work.

# The ACL rules that describe what an user can do are the following:

# on Enable the user: it is possible to authenticate as this user.

# off Disable the user: it's no longer possible to authenticate

# with this user, however the already authenticated connections

# will still work.

# +<command> Allow the execution of that command

# -<command> Disallow the execution of that command

# +@<category> Allow the execution of all the commands in such category

# with valid categories are like @admin, @set, @sortedset, ...

# and so forth, see the full list in the server.c file where

# the Redis command table is described and defined.

# The special category @all means all the commands, but currently

# present in the server, and that will be loaded in the future

# via modules.

# +<command>|subcommand Allow a specific subcommand of an otherwise

# disabled command. Note that this form is not

# allowed as negative like -DEBUG|SEGFAULT, but

# only additive starting with "+".

# allcommands Alias for +@all. Note that it implies the ability to execute

# all the future commands loaded via the modules system.

# nocommands Alias for -@all.

# ~<pattern> Add a pattern of keys that can be mentioned as part of

# commands. For instance ~* allows all the keys. The pattern

# is a glob-style pattern like the one of KEYS.

# It is possible to specify multiple patterns.

# allkeys Alias for ~*

# resetkeys Flush the list of allowed keys patterns.

# ><password> Add this passowrd to the list of valid password for the user.

# For example >mypass will add "mypass" to the list.

# This directive clears the "nopass" flag (see later).

# <<password> Remove this password from the list of valid passwords.

# nopass All the set passwords of the user are removed, and the user

# is flagged as requiring no password: it means that every

# password will work against this user. If this directive is

# used for the default user, every new connection will be

# immediately authenticated with the default user without

# any explicit AUTH command required. Note that the "resetpass"

# directive will clear this condition.

# resetpass Flush the list of allowed passwords. Moreover removes the

# "nopass" status. After "resetpass" the user has no associated

# passwords and there is no way to authenticate without adding

# some password (or setting it as "nopass" later).

# reset Performs the following actions: resetpass, resetkeys, off,

# -@all. The user returns to the same state it has immediately

# after its creation.

# ACL rules can be specified in any order: for instance you can start with

# passwords, then flags, or key patterns. However note that the additive

# and subtractive rules will CHANGE MEANING depending on the ordering.

# For instance see the following example:

# user alice on +@all -DEBUG ~* >somepassword

# This will allow "alice" to use all the commands with the exception of the

# DEBUG command, since +@all added all the commands to the set of the commands

# alice can use, and later DEBUG was removed. However if we invert the order

# of two ACL rules the result will be different:

# user alice on -DEBUG +@all ~* >somepassword

# Now DEBUG was removed when alice had yet no commands in the set of allowed

# commands, later all the commands are added, so the user will be able to

# execute everything.

# Basically ACL rules are processed left-to-right.

# For more information about ACL configuration please refer to

# the Redis web site at https://redis.io/topics/acl

# ACL LOG

# The ACL Log tracks failed commands and authentication events associated

# with ACLs. The ACL Log is useful to troubleshoot failed commands blocked

# by ACLs. The ACL Log is stored in memory. You can reclaim memory with

# ACL LOG RESET. Define the maximum entry length of the ACL Log below.

acllog-max-len 128

# Using an external ACL file

# Instead of configuring users here in this file, it is possible to use

# a stand-alone file just listing users. The two methods cannot be mixed:

# if you configure users here and at the same time you activate the exteranl

# ACL file, the server will refuse to start.

# The format of the external ACL user file is exactly the same as the

# format that is used inside redis.conf to describe users.

# aclfile /etc/redis/users.acl

# IMPORTANT NOTE: starting with Redis 6 "requirepass" is just a compatiblity

# layer on top of the new ACL system. The option effect will be just setting

# the password for the default user. Clients will still authenticate using

# AUTH <password> as usually, or more explicitly with AUTH default <password>

# if they follow the new protocol: both will work.

# requirepass foobared

# Command renaming (DEPRECATED).

# ------------------------------------------------------------------------

# WARNING: avoid using this option if possible. Instead use ACLs to remove

# commands from the default user, and put them only in some admin user you

# create for administrative purposes.

# ------------------------------------------------------------------------

# It is possible to change the name of dangerous commands in a shared

# environment. For instance the CONFIG command may be renamed into something

# hard to guess so that it will still be available for internal-use tools

# but not available for general clients.

# Example:

# rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52

# It is also possible to completely kill a command by renaming it into

# an empty string:

# rename-command CONFIG ""

# Please note that changing the name of commands that are logged into the

# AOF file or transmitted to replicas may cause problems.

################################### CLIENTS ####################################

# Set the max number of connected clients at the same time. By default

# this limit is set to 10000 clients, however if the Redis server is not

# able to configure the process file limit to allow for the specified limit

# the max number of allowed clients is set to the current file limit

# minus 32 (as Redis reserves a few file descriptors for internal uses).

# Once the limit is reached Redis will close all the new connections sending

# an error 'max number of clients reached'.

# IMPORTANT: When Redis Cluster is used, the max number of connections is also

# shared with the cluster bus: every node in the cluster will use two

# connections, one incoming and another outgoing. It is important to size the

# limit accordingly in case of very large clusters.

# maxclients 10000

############################## MEMORY MANAGEMENT ################################

# Set a memory usage limit to the specified amount of bytes.

# When the memory limit is reached Redis will try to remove keys

# according to the eviction policy selected (see maxmemory-policy).

# If Redis can't remove keys according to the policy, or if the policy is

# set to 'noeviction', Redis will start to reply with errors to commands

# that would use more memory, like SET, LPUSH, and so on, and will continue

# to reply to read-only commands like GET.

# This option is usually useful when using Redis as an LRU or LFU cache, or to

# set a hard memory limit for an instance (using the 'noeviction' policy).

# WARNING: If you have replicas attached to an instance with maxmemory on,

# the size of the output buffers needed to feed the replicas are subtracted

# from the used memory count, so that network problems / resyncs will

# not trigger a loop where keys are evicted, and in turn the output

# buffer of replicas is full with DELs of keys evicted triggering the deletion

# of more keys, and so forth until the database is completely emptied.

# In short... if you have replicas attached it is suggested that you set a lower

# limit for maxmemory so that there is some free RAM on the system for replica

# output buffers (but this is not needed if the policy is 'noeviction').

# maxmemory <bytes>

# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory

# is reached. You can select one from the following behaviors:

# volatile-lru -> Evict using approximated LRU, only keys with an expire set.

# allkeys-lru -> Evict any key using approximated LRU.

# volatile-lfu -> Evict using approximated LFU, only keys with an expire set.

# allkeys-lfu -> Evict any key using approximated LFU.

# volatile-random -> Remove a random key having an expire set.

# allkeys-random -> Remove a random key, any key.

# volatile-ttl -> Remove the key with the nearest expire time (minor TTL)

# noeviction -> Don't evict anything, just return an error on write operations.

# LRU means Least Recently Used

# LFU means Least Frequently Used

# Both LRU, LFU and volatile-ttl are implemented using approximated

# randomized algorithms.

# Note: with any of the above policies, Redis will return an error on write

# operations, when there are no suitable keys for eviction.

# At the date of writing these commands are: set setnx setex append

# incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd

# sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby

# zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby

# getset mset msetnx exec sort

# The default is:

# maxmemory-policy noeviction

# LRU, LFU and minimal TTL algorithms are not precise algorithms but approximated

# algorithms (in order to save memory), so you can tune it for speed or

# accuracy. For default Redis will check five keys and pick the one that was

# used less recently, you can change the sample size using the following

# configuration directive.

# The default of 5 produces good enough results. 10 Approximates very closely

# true LRU but costs more CPU. 3 is faster but not very accurate.

# maxmemory-samples 5

# Starting from Redis 5, by default a replica will ignore its maxmemory setting

# (unless it is promoted to master after a failover or manually). It means

# that the eviction of keys will be just handled by the master, sending the

# DEL commands to the replica as keys evict in the master side.

# This behavior ensures that masters and replicas stay consistent, and is usually

# what you want, however if your replica is writable, or you want the replica

# to have a different memory setting, and you are sure all the writes performed

# to the replica are idempotent, then you may change this default (but be sure

# to understand what you are doing).

# Note that since the replica by default does not evict, it may end using more

# memory than the one set via maxmemory (there are certain buffers that may

# be larger on the replica, or data structures may sometimes take more memory

# and so forth). So make sure you monitor your replicas and make sure they

# have enough memory to never hit a real out-of-memory condition before the

# master hits the configured maxmemory setting.

# replica-ignore-maxmemory yes

# Redis reclaims expired keys in two ways: upon access when those keys are

# found to be expired, and also in background, in what is called the

# "active expire key". The key space is slowly and interactively scanned

# looking for expired keys to reclaim, so that it is possible to free memory

# of keys that are expired and will never be accessed again in a short time.

# The default effort of the expire cycle will try to avoid having more than

# ten percent of expired keys still in memory, and will try to avoid consuming

# more than 25% of total memory and to add latency to the system. However

# it is possible to increase the expire "effort" that is normally set to

# "1", to a greater value, up to the value "10". At its maximum value the

# system will use more CPU, longer cycles (and technically may introduce

# more latency), and will tollerate less already expired keys still present

# in the system. It's a tradeoff betweeen memory, CPU and latecy.

# active-expire-effort 1

############################# LAZY FREEING ####################################

# Redis has two primitives to delete keys. One is called DEL and is a blocking

# deletion of the object. It means that the server stops processing new commands

# in order to reclaim all the memory associated with an object in a synchronous

# way. If the key deleted is associated with a small object, the time needed

# in order to execute the DEL command is very small and comparable to most other

# O(1) or O(log_N) commands in Redis. However if the key is associated with an

# aggregated value containing millions of elements, the server can block for

# a long time (even seconds) in order to complete the operation.

# For the above reasons Redis also offers non blocking deletion primitives

# such as UNLINK (non blocking DEL) and the ASYNC option of FLUSHALL and

# FLUSHDB commands, in order to reclaim memory in background. Those commands

# are executed in constant time. Another thread will incrementally free the

# object in the background as fast as possible.

# DEL, UNLINK and ASYNC option of FLUSHALL and FLUSHDB are user-controlled.

# It's up to the design of the application to understand when it is a good

# idea to use one or the other. However the Redis server sometimes has to

# delete keys or flush the whole database as a side effect of other operations.

# Specifically Redis deletes objects independently of a user call in the

# following scenarios:

# 1) On eviction, because of the maxmemory and maxmemory policy configurations,

# in order to make room for new data, without going over the specified

# memory limit.

# 2) Because of expire: when a key with an associated time to live (see the

# EXPIRE command) must be deleted from memory.

# 3) Because of a side effect of a command that stores data on a key that may

# already exist. For example the RENAME command may delete the old key

# content when it is replaced with another one. Similarly SUNIONSTORE

# or SORT with STORE option may delete existing keys. The SET command

# itself removes any old content of the specified key in order to replace

# it with the specified string.

# 4) During replication, when a replica performs a full resynchronization with

# its master, the content of the whole database is removed in order to

# load the RDB file just transferred.

# In all the above cases the default is to delete objects in a blocking way,

# like if DEL was called. However you can configure each case specifically

# in order to instead release memory in a non-blocking way like if UNLINK

# was called, using the following configuration directives.

lazyfree-lazy-eviction no

lazyfree-lazy-expire no

lazyfree-lazy-server-del no

replica-lazy-flush no

# It is also possible, for the case when to replace the user code DEL calls

# with UNLINK calls is not easy, to modify the default behavior of the DEL

# command to act exactly like UNLINK, using the following configuration

# directive:

lazyfree-lazy-user-del no

################################ THREADED I/O #################################

# Redis is mostly single threaded, however there are certain threaded

# operations such as UNLINK, slow I/O accesses and other things that are

# performed on side threads.

# Now it is also possible to handle Redis clients socket reads and writes

# in different I/O threads. Since especially writing is so slow, normally

# Redis users use pipelining in order to speedup the Redis performances per

# core, and spawn multiple instances in order to scale more. Using I/O

# threads it is possible to easily speedup two times Redis without resorting

# to pipelining nor sharding of the instance.

# By default threading is disabled, we suggest enabling it only in machines

# that have at least 4 or more cores, leaving at least one spare core.

# Using more than 8 threads is unlikely to help much. We also recommend using

# threaded I/O only if you actually have performance problems, with Redis

# instances being able to use a quite big percentage of CPU time, otherwise

# there is no point in using this feature.

# So for instance if you have a four cores boxes, try to use 2 or 3 I/O

# threads, if you have a 8 cores, try to use 6 threads. In order to

# enable I/O threads use the following configuration directive:

# io-threads 4

# Setting io-threads to 1 will just use the main thread as usually.

# When I/O threads are enabled, we only use threads for writes, that is

# to thread the write(2) syscall and transfer the client buffers to the

# socket. However it is also possible to enable threading of reads and

# protocol parsing using the following configuration directive, by setting

# it to yes:

# io-threads-do-reads no

# Usually threading reads doesn't help much.

# NOTE 1: This configuration directive cannot be changed at runtime via

# CONFIG SET. Aso this feature currently does not work when SSL is

# enabled.

# NOTE 2: If you want to test the Redis speedup using redis-benchmark, make

# sure you also run the benchmark itself in threaded mode, using the

# --threads option to match the number of Redis theads, otherwise you'll not

# be able to notice the improvements.

############################## APPEND ONLY MODE ###############################

# By default Redis asynchronously dumps the dataset on disk. This mode is

# good enough in many applications, but an issue with the Redis process or

# a power outage may result into a few minutes of writes lost (depending on

# the configured save points).

# The Append Only File is an alternative persistence mode that provides

# much better durability. For instance using the default data fsync policy

# (see later in the config file) Redis can lose just one second of writes in a

# dramatic event like a server power outage, or a single write if something

# wrong with the Redis process itself happens, but the operating system is

# still running correctly.

# AOF and RDB persistence can be enabled at the same time without problems.

# If the AOF is enabled on startup Redis will load the AOF, that is the file

# with the better durability guarantees.

# Please check http://redis.io/topics/persistence for more information.

appendonly no

# The name of the append only file (default: "appendonly.aof")

appendfilename "appendonly-7000.aof"

# The fsync() call tells the Operating System to actually write data on disk

# instead of waiting for more data in the output buffer. Some OS will really flush

# data on disk, some other OS will just try to do it ASAP.

# Redis supports three different modes:

# no: don't fsync, just let the OS flush the data when it wants. Faster.

# always: fsync after every write to the append only log. Slow, Safest.

# everysec: fsync only one time every second. Compromise.

# The default is "everysec", as that's usually the right compromise between

# speed and data safety. It's up to you to understand if you can relax this to

# "no" that will let the operating system flush the output buffer when

# it wants, for better performances (but if you can live with the idea of

# some data loss consider the default persistence mode that's snapshotting),

# or on the contrary, use "always" that's very slow but a bit safer than

# everysec.

# More details please check the following article:

# http://antirez.com/post/redis-persistence-demystified.html

# If unsure, use "everysec".

# appendfsync always

appendfsync everysec

# appendfsync no

# When the AOF fsync policy is set to always or everysec, and a background

# saving process (a background save or AOF log background rewriting) is

# performing a lot of I/O against the disk, in some Linux configurations

# Redis may block too long on the fsync() call. Note that there is no fix for

# this currently, as even performing fsync in a different thread will block

# our synchronous write(2) call.

# In order to mitigate this problem it's possible to use the following option

# that will prevent fsync() from being called in the main process while a

# BGSAVE or BGREWRITEAOF is in progress.

# This means that while another child is saving, the durability of Redis is

# the same as "appendfsync none". In practical terms, this means that it is

# possible to lose up to 30 seconds of log in the worst scenario (with the

# default Linux settings).

# If you have latency problems turn this to "yes". Otherwise leave it as

# "no" that is the safest pick from the point of view of durability.

no-appendfsync-on-rewrite no

# Automatic rewrite of the append only file.

# Redis is able to automatically rewrite the log file implicitly calling

# BGREWRITEAOF when the AOF log size grows by the specified percentage.

# This is how it works: Redis remembers the size of the AOF file after the

# latest rewrite (if no rewrite has happened since the restart, the size of

# the AOF at startup is used).

# This base size is compared to the current size. If the current size is

# bigger than the specified percentage, the rewrite is triggered. Also

# you need to specify a minimal size for the AOF file to be rewritten, this

# is useful to avoid rewriting the AOF file even if the percentage increase

# is reached but it is still pretty small.

# Specify a percentage of zero in order to disable the automatic AOF

# rewrite feature.

auto-aof-rewrite-percentage 100

auto-aof-rewrite-min-size 64mb

# An AOF file may be found to be truncated at the end during the Redis

# startup process, when the AOF data gets loaded back into memory.

# This may happen when the system where Redis is running

# crashes, especially when an ext4 filesystem is mounted without the

# data=ordered option (however this can't happen when Redis itself

# crashes or aborts but the operating system still works correctly).

# Redis can either exit with an error when this happens, or load as much

# data as possible (the default now) and start if the AOF file is found

# to be truncated at the end. The following option controls this behavior.

# If aof-load-truncated is set to yes, a truncated AOF file is loaded and

# the Redis server starts emitting a log to inform the user of the event.

# Otherwise if the option is set to no, the server aborts with an error

# and refuses to start. When the option is set to no, the user requires

# to fix the AOF file using the "redis-check-aof" utility before to restart

# the server.

# Note that if the AOF file will be found to be corrupted in the middle

# the server will still exit with an error. This option only applies when

# Redis will try to read more data from the AOF file but not enough bytes

# will be found.

aof-load-truncated yes

# When rewriting the AOF file, Redis is able to use an RDB preamble in the

# AOF file for faster rewrites and recoveries. When this option is turned

# on the rewritten AOF file is composed of two different stanzas:

# [RDB file][AOF tail]

# When loading Redis recognizes that the AOF file starts with the "REDIS"

# string and loads the prefixed RDB file, and continues loading the AOF

# tail.

aof-use-rdb-preamble yes

################################ LUA SCRIPTING ###############################

# Max execution time of a Lua script in milliseconds.

# If the maximum execution time is reached Redis will log that a script is

# still in execution after the maximum allowed time and will start to

# reply to queries with an error.

# When a long running script exceeds the maximum execution time only the

# SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be

# used to stop a script that did not yet called write commands. The second

# is the only way to shut down the server in the case a write command was

# already issued by the script but the user doesn't want to wait for the natural

# termination of the script.

# Set it to 0 or a negative value for unlimited execution without warnings.

lua-time-limit 5000

################################ REDIS CLUSTER ###############################

# Normal Redis instances can't be part of a Redis Cluster; only nodes that are

# started as cluster nodes can. In order to start a Redis instance as a

# cluster node enable the cluster support uncommenting the following:

cluster-enabled yes

# Every cluster node has a cluster configuration file. This file is not

# intended to be edited by hand. It is created and updated by Redis nodes.

# Every Redis Cluster node requires a different cluster configuration file.

# Make sure that instances running in the same system do not have

# overlapping cluster configuration file names.

cluster-config-file nodes-7000.conf

# Cluster node timeout is the amount of milliseconds a node must be unreachable

# for it to be considered in failure state.

# Most other internal time limits are multiple of the node timeout.

cluster-node-timeout 5000

# A replica of a failing master will avoid to start a failover if its data

# looks too old.

# There is no simple way for a replica to actually have an exact measure of

# its "data age", so the following two checks are performed:

# 1) If there are multiple replicas able to failover, they exchange messages

# in order to try to give an advantage to the replica with the best

# replication offset (more data from the master processed).

# Replicas will try to get their rank by offset, and apply to the start

# of the failover a delay proportional to their rank.

# 2) Every single replica computes the time of the last interaction with

# its master. This can be the last ping or command received (if the master

# is still in the "connected" state), or the time that elapsed since the

# disconnection with the master (if the replication link is currently down).

# If the last interaction is too old, the replica will not try to failover

# at all.

# The point "2" can be tuned by user. Specifically a replica will not perform

# the failover if, since the last interaction with the master, the time

# elapsed is greater than:

# (node-timeout * replica-validity-factor) + repl-ping-replica-period

# So for example if node-timeout is 30 seconds, and the replica-validity-factor

# is 10, and assuming a default repl-ping-replica-period of 10 seconds, the

# replica will not try to failover if it was not able to talk with the master

# for longer than 310 seconds.

# A large replica-validity-factor may allow replicas with too old data to failover

# a master, while a too small value may prevent the cluster from being able to

# elect a replica at all.

# For maximum availability, it is possible to set the replica-validity-factor

# to a value of 0, which means, that replicas will always try to failover the

# master regardless of the last time they interacted with the master.

# (However they'll always try to apply a delay proportional to their

# offset rank).

# Zero is the only value able to guarantee that when all the partitions heal

# the cluster will always be able to continue.

# cluster-replica-validity-factor 10

# Cluster replicas are able to migrate to orphaned masters, that are masters

# that are left without working replicas. This improves the cluster ability

# to resist to failures as otherwise an orphaned master can't be failed over

# in case of failure if it has no working replicas.

# Replicas migrate to orphaned masters only if there are still at least a

# given number of other working replicas for their old master. This number

# is the "migration barrier". A migration barrier of 1 means that a replica

# will migrate only if there is at least 1 other working replica for its master

# and so forth. It usually reflects the number of replicas you want for every

# master in your cluster.

# Default is 1 (replicas migrate only if their masters remain with at least

# one replica). To disable migration just set it to a very large value.

# A value of 0 can be set but is useful only for debugging and dangerous

# in production.

# cluster-migration-barrier 1

# By default Redis Cluster nodes stop accepting queries if they detect there

# is at least an hash slot uncovered (no available node is serving it).

# This way if the cluster is partially down (for example a range of hash slots

# are no longer covered) all the cluster becomes, eventually, unavailable.

# It automatically returns available as soon as all the slots are covered again.

# However sometimes you want the subset of the cluster which is working,

# to continue to accept queries for the part of the key space that is still

# covered. In order to do so, just set the cluster-require-full-coverage

# option to no.

# cluster-require-full-coverage yes

# This option, when set to yes, prevents replicas from trying to failover its

# master during master failures. However the master can still perform a

# manual failover, if forced to do so.

# This is useful in different scenarios, especially in the case of multiple

# data center operations, where we want one side to never be promoted if not

# in the case of a total DC failure.

# cluster-replica-no-failover no

# This option, when set to yes, allows nodes to serve read traffic while the

# the cluster is in a down state, as long as it believes it owns the slots.

# This is useful for two cases. The first case is for when an application

# doesn't require consistency of data during node failures or network partitions.

# One example of this is a cache, where as long as the node has the data it

# should be able to serve it.

# The second use case is for configurations that don't meet the recommended

# three shards but want to enable cluster mode and scale later. A

# master outage in a 1 or 2 shard configuration causes a read/write outage to the

# entire cluster without this option set, with it set there is only a write outage.

# Without a quorum of masters, slot ownership will not change automatically.

# cluster-allow-reads-when-down no

# In order to setup your cluster make sure to read the documentation

# available at http://redis.io web site.

########################## CLUSTER DOCKER/NAT support ########################

# In certain deployments, Redis Cluster nodes address discovery fails, because

# addresses are NAT-ted or because ports are forwarded (the typical case is

# Docker and other containers).

# In order to make Redis Cluster working in such environments, a static

# configuration where each node knows its public address is needed. The

# following two options are used for this scope, and are:

# * cluster-announce-ip

# * cluster-announce-port

# * cluster-announce-bus-port

# Each instruct the node about its address, client port, and cluster message

# bus port. The information is then published in the header of the bus packets

# so that other nodes will be able to correctly map the address of the node

# publishing the information.

# If the above options are not used, the normal Redis Cluster auto-detection

# will be used instead.

# Note that when remapped, the bus port may not be at the fixed offset of

# clients port + 10000, so you can specify any port and bus-port depending

# on how they get remapped. If the bus-port is not set, a fixed offset of

# 10000 will be used as usually.

# Example:

# cluster-announce-ip 10.1.1.5

# cluster-announce-port 6379

# cluster-announce-bus-port 6380

################################## SLOW LOG ###################################

# The Redis Slow Log is a system to log queries that exceeded a specified

# execution time. The execution time does not include the I/O operations

# like talking with the client, sending the reply and so forth,

# but just the time needed to actually execute the command (this is the only

# stage of command execution where the thread is blocked and can not serve

# other requests in the meantime).

# You can configure the slow log with two parameters: one tells Redis

# what is the execution time, in microseconds, to exceed in order for the

# command to get logged, and the other parameter is the length of the

# slow log. When a new command is logged the oldest one is removed from the

# queue of logged commands.

# The following time is expressed in microseconds, so 1000000 is equivalent

# to one second. Note that a negative number disables the slow log, while

# a value of zero forces the logging of every command.

slowlog-log-slower-than 10000

# There is no limit to this length. Just be aware that it will consume memory.

# You can reclaim memory used by the slow log with SLOWLOG RESET.

slowlog-max-len 128

################################ LATENCY MONITOR ##############################

# The Redis latency monitoring subsystem samples different operations

# at runtime in order to collect data related to possible sources of

# latency of a Redis instance.

# Via the LATENCY command this information is available to the user that can

# print graphs and obtain reports.

# The system only logs operations that were performed in a time equal or

# greater than the amount of milliseconds specified via the

# latency-monitor-threshold configuration directive. When its value is set

# to zero, the latency monitor is turned off.

# By default latency monitoring is disabled since it is mostly not needed

# if you don't have latency issues, and collecting data has a performance

# impact, that while very small, can be measured under big load. Latency

# monitoring can easily be enabled at runtime using the command

# "CONFIG SET latency-monitor-threshold <milliseconds>" if needed.

latency-monitor-threshold 0

############################# EVENT NOTIFICATION ##############################

# Redis can notify Pub/Sub clients about events happening in the key space.

# This feature is documented at http://redis.io/topics/notifications

# For instance if keyspace events notification is enabled, and a client

# performs a DEL operation on key "foo" stored in the Database 0, two

# messages will be published via Pub/Sub:

# PUBLISH __keyspace@0__:foo del

# PUBLISH __keyevent@0__:del foo

# It is possible to select the events that Redis will notify among a set

# of classes. Every class is identified by a single character:

# K Keyspace events, published with __keyspace@<db>__ prefix.

# E Keyevent events, published with __keyevent@<db>__ prefix.

# g Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ...

# $ String commands

# l List commands

# s Set commands

# h Hash commands

# z Sorted set commands

# x Expired events (events generated every time a key expires)

# e Evicted events (events generated when a key is evicted for maxmemory)

# t Stream commands

# m Key-miss events (Note: It is not included in the 'A' class)

# A Alias for g$lshzxet, so that the "AKE" string means all the events

# (Except key-miss events which are excluded from 'A' due to their

# unique nature).

# The "notify-keyspace-events" takes as argument a string that is composed

# of zero or multiple characters. The empty string means that notifications

# are disabled.

# Example: to enable list and generic events, from the point of view of the

# event name, use:

# notify-keyspace-events Elg

# Example 2: to get the stream of the expired keys subscribing to channel

# name __keyevent@0__:expired use:

# notify-keyspace-events Ex

# By default all notifications are disabled because most users don't need

# this feature and the feature has some overhead. Note that if you don't

# specify at least one of K or E, no events will be delivered.

notify-keyspace-events ""

############################### GOPHER SERVER #################################

# Redis contains an implementation of the Gopher protocol, as specified in

# the RFC 1436 (https://www.ietf.org/rfc/rfc1436.txt).

# The Gopher protocol was very popular in the late '90s. It is an alternative

# to the web, and the implementation both server and client side is so simple

# that the Redis server has just 100 lines of code in order to implement this

# support.

# What do you do with Gopher nowadays? Well Gopher never *really* died, and

# lately there is a movement in order for the Gopher more hierarchical content

# composed of just plain text documents to be resurrected. Some want a simpler

# internet, others believe that the mainstream internet became too much

# controlled, and it's cool to create an alternative space for people that

# want a bit of fresh air.

# Anyway for the 10nth birthday of the Redis, we gave it the Gopher protocol

# as a gift.

# --- HOW IT WORKS? ---

# The Redis Gopher support uses the inline protocol of Redis, and specifically

# two kind of inline requests that were anyway illegal: an empty request

# or any request that starts with "/" (there are no Redis commands starting

# with such a slash). Normal RESP2/RESP3 requests are completely out of the

# path of the Gopher protocol implementation and are served as usually as well.

# If you open a connection to Redis when Gopher is enabled and send it

# a string like "/foo", if there is a key named "/foo" it is served via the

# Gopher protocol.

# In order to create a real Gopher "hole" (the name of a Gopher site in Gopher

# talking), you likely need a script like the following:

# https://github.com/antirez/gopher2redis

# --- SECURITY WARNING ---

# If you plan to put Redis on the internet in a publicly accessible address

# to server Gopher pages MAKE SURE TO SET A PASSWORD to the instance.

# Once a password is set:

# 1. The Gopher server (when enabled, not by default) will still serve

# content via Gopher.

# 2. However other commands cannot be called before the client will

# authenticate.

# So use the 'requirepass' option to protect your instance.

# To enable Gopher support uncomment the following line and set

# the option from no (the default) to yes.

# gopher-enabled no

############################### ADVANCED CONFIG ###############################

# Hashes are encoded using a memory efficient data structure when they have a

# small number of entries, and the biggest entry does not exceed a given

# threshold. These thresholds can be configured using the following directives.

hash-max-ziplist-entries 512

hash-max-ziplist-value 64

# Lists are also encoded in a special way to save a lot of space.

# The number of entries allowed per internal list node can be specified

# as a fixed maximum size or a maximum number of elements.

# For a fixed maximum size, use -5 through -1, meaning:

# -5: max size: 64 Kb <-- not recommended for normal workloads

# -4: max size: 32 Kb <-- not recommended

# -3: max size: 16 Kb <-- probably not recommended

# -2: max size: 8 Kb <-- good

# -1: max size: 4 Kb <-- good

# Positive numbers mean store up to _exactly_ that number of elements

# per list node.

# The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size),

# but if your use case is unique, adjust the settings as necessary.

list-max-ziplist-size -2

# Lists may also be compressed.

# Compress depth is the number of quicklist ziplist nodes from *each* side of

# the list to *exclude* from compression. The head and tail of the list

# are always uncompressed for fast push/pop operations. Settings are:

# 0: disable all list compression

# 1: depth 1 means "don't start compressing until after 1 node into the list,

# going from either the head or tail"

# So: [head]->node->node->...->node->[tail]

# [head], [tail] will always be uncompressed; inner nodes will compress.

# 2: [head]->[next]->node->node->...->node->[prev]->[tail]

# 2 here means: don't compress head or head->next or tail->prev or tail,

# but compress all nodes between them.

# 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail]

# etc.

list-compress-depth 0

# Sets have a special encoding in just one case: when a set is composed

# of just strings that happen to be integers in radix 10 in the range

# of 64 bit signed integers.

# The following configuration setting sets the limit in the size of the

# set in order to use this special memory saving encoding.

set-max-intset-entries 512

# Similarly to hashes and lists, sorted sets are also specially encoded in

# order to save a lot of space. This encoding is only used when the length and

# elements of a sorted set are below the following limits:

zset-max-ziplist-entries 128

zset-max-ziplist-value 64

# HyperLogLog sparse representation bytes limit. The limit includes the

# 16 bytes header. When an HyperLogLog using the sparse representation crosses

# this limit, it is converted into the dense representation.

# A value greater than 16000 is totally useless, since at that point the

# dense representation is more memory efficient.

# The suggested value is ~ 3000 in order to have the benefits of

# the space efficient encoding without slowing down too much PFADD,

# which is O(N) with the sparse encoding. The value can be raised to

# ~ 10000 when CPU is not a concern, but space is, and the data set is

# composed of many HyperLogLogs with cardinality in the 0 - 15000 range.

hll-sparse-max-bytes 3000

# Streams macro node max size / items. The stream data structure is a radix

# tree of big nodes that encode multiple items inside. Using this configuration

# it is possible to configure how big a single node can be in bytes, and the

# maximum number of items it may contain before switching to a new node when

# appending new stream entries. If any of the following settings are set to

# zero, the limit is ignored, so for instance it is possible to set just a

# max entires limit by setting max-bytes to 0 and max-entries to the desired

# value.

stream-node-max-bytes 4kb

stream-node-max-entries 100

# Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in

# order to help rehashing the main Redis hash table (the one mapping top-level

# keys to values). The hash table implementation Redis uses (see dict.c)

# performs a lazy rehashing: the more operation you run into a hash table

# that is rehashing, the more rehashing "steps" are performed, so if the

# server is idle the rehashing is never complete and some more memory is used

# by the hash table.

# The default is to use this millisecond 10 times every second in order to

# actively rehash the main dictionaries, freeing memory when possible.

# If unsure:

# use "activerehashing no" if you have hard latency requirements and it is

# not a good thing in your environment that Redis can reply from time to time

# to queries with 2 milliseconds delay.

# use "activerehashing yes" if you don't have such hard requirements but

# want to free memory asap when possible.

activerehashing yes

# The client output buffer limits can be used to force disconnection of clients

# that are not reading data from the server fast enough for some reason (a

# common reason is that a Pub/Sub client can't consume messages as fast as the

# publisher can produce them).

# The limit can be set differently for the three different classes of clients:

# normal -> normal clients including MONITOR clients

# replica -> replica clients

# pubsub -> clients subscribed to at least one pubsub channel or pattern

# The syntax of every client-output-buffer-limit directive is the following:

# client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds>

# A client is immediately disconnected once the hard limit is reached, or if

# the soft limit is reached and remains reached for the specified number of

# seconds (continuously).

# So for instance if the hard limit is 32 megabytes and the soft limit is

# 16 megabytes / 10 seconds, the client will get disconnected immediately

# if the size of the output buffers reach 32 megabytes, but will also get

# disconnected if the client reaches 16 megabytes and continuously overcomes

# the limit for 10 seconds.

# By default normal clients are not limited because they don't receive data

# without asking (in a push way), but just after a request, so only

# asynchronous clients may create a scenario where data is requested faster

# than it can read.

# Instead there is a default limit for pubsub and replica clients, since

# subscribers and replicas receive data in a push fashion.

# Both the hard or the soft limit can be disabled by setting them to zero.

client-output-buffer-limit normal 0 0 0

client-output-buffer-limit replica 256mb 64mb 60

client-output-buffer-limit pubsub 32mb 8mb 60

# Client query buffers accumulate new commands. They are limited to a fixed

# amount by default in order to avoid that a protocol desynchronization (for

# instance due to a bug in the client) will lead to unbound memory usage in

# the query buffer. However you can configure it here if you have very special

# needs, such us huge multi/exec requests or alike.

# client-query-buffer-limit 1gb

# In the Redis protocol, bulk requests, that are, elements representing single

# strings, are normally limited ot 512 mb. However you can change this limit

# here.

# proto-max-bulk-len 512mb

# Redis calls an internal function to perform many background tasks, like

# closing connections of clients in timeout, purging expired keys that are

# never requested, and so forth.

# Not all tasks are performed with the same frequency, but Redis checks for

# tasks to perform according to the specified "hz" value.

# By default "hz" is set to 10. Raising the value will use more CPU when

# Redis is idle, but at the same time will make Redis more responsive when

# there are many keys expiring at the same time, and timeouts may be

# handled with more precision.

# The range is between 1 and 500, however a value over 100 is usually not

# a good idea. Most users should use the default of 10 and raise this up to

# 100 only in environments where very low latency is required.

hz 10

# Normally it is useful to have an HZ value which is proportional to the

# number of clients connected. This is useful in order, for instance, to

# avoid too many clients are processed for each background task invocation

# in order to avoid latency spikes.

# Since the default HZ value by default is conservatively set to 10, Redis

# offers, and enables by default, the ability to use an adaptive HZ value

# which will temporary raise when there are many connected clients.

# When dynamic HZ is enabled, the actual configured HZ will be used

# as a baseline, but multiples of the configured HZ value will be actually

# used as needed once more clients are connected. In this way an idle

# instance will use very little CPU time while a busy instance will be

# more responsive.

dynamic-hz yes

# When a child rewrites the AOF file, if the following option is enabled

# the file will be fsync-ed every 32 MB of data generated. This is useful

# in order to commit the file to the disk more incrementally and avoid

# big latency spikes.

aof-rewrite-incremental-fsync yes

# When redis saves RDB file, if the following option is enabled

# the file will be fsync-ed every 32 MB of data generated. This is useful

# in order to commit the file to the disk more incrementally and avoid

# big latency spikes.

rdb-save-incremental-fsync yes

# Redis LFU eviction (see maxmemory setting) can be tuned. However it is a good

# idea to start with the default settings and only change them after investigating

# how to improve the performances and how the keys LFU change over time, which

# is possible to inspect via the OBJECT FREQ command.

# There are two tunable parameters in the Redis LFU implementation: the

# counter logarithm factor and the counter decay time. It is important to

# understand what the two parameters mean before changing them.

# The LFU counter is just 8 bits per key, it's maximum value is 255, so Redis

# uses a probabilistic increment with logarithmic behavior. Given the value

# of the old counter, when a key is accessed, the counter is incremented in

# this way:

# 1. A random number R between 0 and 1 is extracted.

# 2. A probability P is calculated as 1/(old_value*lfu_log_factor+1).

# 3. The counter is incremented only if R < P.

# The default lfu-log-factor is 10. This is a table of how the frequency

# counter changes with a different number of accesses with different

# logarithmic factors:

# +--------+------------+------------+------------+------------+------------+

# +--------+------------+------------+------------+------------+------------+

# | 0 | 104 | 255 | 255 | 255 | 255 |

# +--------+------------+------------+------------+------------+------------+

# | 1 | 18 | 49 | 255 | 255 | 255 |

# +--------+------------+------------+------------+------------+------------+

# | 10 | 10 | 18 | 142 | 255 | 255 |

# +--------+------------+------------+------------+------------+------------+

# | 100 | 8 | 11 | 49 | 143 | 255 |

# +--------+------------+------------+------------+------------+------------+

# NOTE: The above table was obtained by running the following commands:

# redis-benchmark -n 1000000 incr foo

# redis-cli object freq foo

# NOTE 2: The counter initial value is 5 in order to give new objects a chance

# to accumulate hits.

# The counter decay time is the time, in minutes, that must elapse in order

# for the key counter to be divided by two (or decremented if it has a value

# less <= 10).

# The default value for the lfu-decay-time is 1. A Special value of 0 means to

# decay the counter every time it happens to be scanned.

# lfu-log-factor 10

# lfu-decay-time 1

########################### ACTIVE DEFRAGMENTATION #######################

# What is active defragmentation?

# -------------------------------

# Active (online) defragmentation allows a Redis server to compact the

# spaces left between small allocations and deallocations of data in memory,

# thus allowing to reclaim back memory.

# Fragmentation is a natural process that happens with every allocator (but

# less so with Jemalloc, fortunately) and certain workloads. Normally a server

# restart is needed in order to lower the fragmentation, or at least to flush

# away all the data and create it again. However thanks to this feature

# implemented by Oran Agra for Redis 4.0 this process can happen at runtime

# in an "hot" way, while the server is running.

# Basically when the fragmentation is over a certain level (see the

# configuration options below) Redis will start to create new copies of the

# values in contiguous memory regions by exploiting certain specific Jemalloc

# features (in order to understand if an allocation is causing fragmentation

# and to allocate it in a better place), and at the same time, will release the

# old copies of the data. This process, repeated incrementally for all the keys

# will cause the fragmentation to drop back to normal values.

# Important things to understand:

# 1. This feature is disabled by default, and only works if you compiled Redis

# to use the copy of Jemalloc we ship with the source code of Redis.

# This is the default with Linux builds.

# 2. You never need to enable this feature if you don't have fragmentation

# issues.

# 3. Once you experience fragmentation, you can enable this feature when

# needed with the command "CONFIG SET activedefrag yes".

# The configuration parameters are able to fine tune the behavior of the

# defragmentation process. If you are not sure about what they mean it is

# a good idea to leave the defaults untouched.

# Enabled active defragmentation

# activedefrag no

# Minimum amount of fragmentation waste to start active defrag

# active-defrag-ignore-bytes 100mb

# Minimum percentage of fragmentation to start active defrag

# active-defrag-threshold-lower 10

# Maximum percentage of fragmentation at which we use maximum effort

# active-defrag-threshold-upper 100

# Minimal effort for defrag in CPU percentage, to be used when the lower

# threshold is reached

# active-defrag-cycle-min 1

# Maximal effort for defrag in CPU percentage, to be used when the upper

# threshold is reached

# active-defrag-cycle-max 25

# Maximum number of set/hash/zset/list fields that will be processed from

# the main dictionary scan

# active-defrag-max-scan-fields 1000

# Jemalloc background thread for purging will be enabled by default

jemalloc-bg-thread yes

# It is possible to pin different threads and processes of Redis to specific

# CPUs in your system, in order to maximize the performances of the server.

# This is useful both in order to pin different Redis threads in different

# CPUs, but also in order to make sure that multiple Redis instances running

# in the same host will be pinned to different CPUs.

# Normally you can do this using the "taskset" command, however it is also

# possible to this via Redis configuration directly, both in Linux and FreeBSD.

# You can pin the server/IO threads, bio threads, aof rewrite child process, and

# the bgsave child process. The syntax to specify the cpu list is the same as

# the taskset command:

# Set redis server/io threads to cpu affinity 0,2,4,6:

# server_cpulist 0-7:2

# Set bio threads to cpu affinity 1,3:

# bio_cpulist 1,3

# Set aof rewrite child process to cpu affinity 8,9,10,11:

# aof_rewrite_cpulist 8-11

# Set bgsave child process to cpu affinity 1,10,11

# bgsave_cpulist 1,10-11

# Generated by CONFIG REWRITE

user default on nopass ~* +@all

其它目录端口一样,只是进行了一次全局替换将配置文件中的7000替换为7001、7002....罢了。

抽取上面的配置,我主要只是修改了如下的配置信息:


cluster-enabled yes # 开启集群

bind 0.0.0.0 # 允许所有用户访问

port 7000 # redis启动的端口

dbfilename "dump-7000.rdb" # 由于集群下有许多 redis 节点,因此存储文件也需要不同


pidfile "/var/run/redis_7000.pid" # 修改进程文件

appendonly yes # 开启 aof 持久化

appendfilename "appendonly-7000.aof" # aof 持久化名称

cluster-config-file nodes-7000.conf # 修改集群配置

cluster-node-timeout 5000 # 修改集群超时时间 5秒

cluster-enabled yes # 开启集群

bind 0.0.0.0 # 允许所有用户访问

port 7000 # redis启动的端口

dbfilename "dump-7000.rdb" # 由于集群下有许多 redis 节点,因此存储文件也需要不同

pidfile "/var/run/redis_7000.pid" # 修改进程文件

appendonly yes # 开启 aof 持久化

appendfilename "appendonly-7000.aof" # aof 持久化名称

cluster-config-file nodes-7000.conf # 修改集群配置

cluster-node-timeout 5000 # 修改集群超时时间 5秒

第三步:启动这 6 个 redis 节点

/usr/local/redis/redis-server ./redis.conf

1	/usr/local/redis/redis-server ./redis.conf

第四步:执行命令,启动集群模式

启动集群模式需要使用 redis-cli 命令,如下所示

redis-cli --cluster create 192.168.0.81:7000 192.168.0.81:7001 192.168.0.81:7002 192.168.0.81:7003 192.168.0.81:7004 192.168.0.81:7005 --cluster-replicas 1

1	redis-cli --cluster create 192.168.0.81:7000 192.168.0.81:7001 192.168.0.81:7002 192.168.0.81:7003 192.168.0.81:7004 192.168.0.81:7005 --cluster-replicas 1

其中参数 --cluster-replicas 表示集群主节点需要多少个从节点,由于我们这里是三主三从的形式,因此参数的值为 1 ,代表每个主节点主需要一个从节点即可。

执行完毕后我们就能看到如下的界面

如上图所示,左边的M代表主节点,S代表从节点,且每个主节点时命令自动为你规划的,我们可以通过上图标注的红线看到,每一个主节点都有各自分配的从节点。

并且图中的 slots:[0-5460] 、slots:[5461-10922]、slots:[10923-16383] 代表着主节点各自分配到的 hash 槽。

这里请注意了,有且仅有主节点才能被分配到 hash 槽,redis 集群下,hash槽一共为16384个,它会近乎平均的分配给每个主节点。(注:从节点是没有 hash 槽的)

当客户端向 Redis 写入一条数据时,该命令的 key 会经过 hash 计算,且计算的结果永远落在0-16384 这个区间内。例如一条 Redis 命令计算出来的结果为 5467 ,那么它的记录将会存储在第二台 Master 节点中,并且同步给它的从节点。有点类似于哈希表算法的感觉。

因此,我们只需要在命令行中输入 yes 使用它默认给我们分配的集群模式即可。

执行完 yes 后,我们能看到如下界面就代表集群搭建成功了

在此大功告成,我们来测试一下~

实验(一)、往 slave 从节点写入数据会发生什么

我们随便连接一个节点,这里我选取的是 slave 从节点,端口号为7003,并向从节点写入一条数据。

./redis-cli -p  7003 -c # -c 参数代表集群模式,必加
set name hahahah

1 2	./redis-cli -p 7003 -c # -c 参数代表集群模式,必加 set name hahahah

我们可以知道 slave 从节点不允许被写入数据,但是它这条命令被重定向到自己的主节点7001上了。因此该条数据写入成功。

实验(二)、切换节点再次查看是否有上面设置的这条数据

此时,我登录 7002端口的节点 (注:7002 的从节点是 7005,而我刚才是往 7003 中写的数据,并且该条数据被重定向到 7001上执行了) ,此时我执行这条 get name 命令,它又重定向到 7001中。如下图所示:

实现(三)、杀死 7000 端口主节点

我找到了7000所在的端口,并 kill 了这个进程,想测试它是否能升级自己的 slave 节点为主节点。(注:我们可以在redis 客户端模式下使用命令:cluster nodes 来查看节点信息)

没杀死7000端口的进程前,7000端口为主节点,7003为从节点。如下图所示:

当我杀死7000端口的主节点后,7003自动转换为主节点,如下图所示:

当我再次在目录名为 7000 下执行以下命令,重启曾今的主节点

 /usr/local/redis/redis-server ./redis.conf

1	/usr/local/redis/redis-server ./redis.conf

此时曾今的 7000端口主节点已经沦为 7003 的从节点了,如下图所示:

当我们如果看到这一幕就代表着 Redis 集群确实已经搭建好了。并且确实拥有着高可用的特性。

总结:当客户端执行的一条命令,它会进行自动数据分片,通过 hash 计算散落在集群中的某个主从节点下,当查询数据时也是如此,通过hash计算,去某个主从节点下获取数据。

在集群模式下,我们并不需要手动配置哨兵,他也能做到自动的心跳监测。当主节点宕机,当仁不让的将从节点升级为新的注节点。然而老的主节点修复重启后,将会沦为从节点,为我们的应用系统保驾护航。

暂无

兰陵美酒郁金香

大道至简 Simplicity is the ultimate form of sophistication.

文章评论（0）

你必须登录才能发表评论