（四）、Redis配置文件

Redis配置文件几大构成

Untis单位

# Redis configuration file example.

# 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.

配置了大小单位，定义了基本度量单位，只支持bytes、不支持bit，对大小写不敏感

INCLUDES包含

################################## 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.
#
# Note that 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

redis.conf可以作为总配置文件，包含其他配置文件

GENEGAL通用

################################# 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.
# When Redis is supervised by upstart or systemd, this parameter has no impact.
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
#                        requires "expect stop" in your upstart job config
#   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
#                        on startup, and updating Redis status on a regular
#                        basis.
#   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 pings back to your supervisor.
#
# The default is "no". To run under upstart/systemd, you can simply uncomment
# the line below:
#
# supervised auto

# 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.
#
# Note that on modern Linux systems "/run/redis.pid" is more conforming
# and should be used instead.
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

# To disable the built in crash log, which will possibly produce cleaner core
# dumps when they are needed, uncomment the following:
#
# crash-log-enabled no

# To disable the fast memory check that's run as part of the crash log, which
# will possibly let redis terminate sooner, uncomment the following:
#
# crash-memcheck-enabled no

# 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 and syslog logging is
# disabled. 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 no

# By default, Redis modifies the process title (as seen in 'top' and 'ps') to
# provide some runtime information. It is possible to disable this and leave
# the process name as executed by setting the following to no.
set-proc-title yes

# When changing the process title, Redis uses the following template to construct
# the modified title.
#
# Template variables are specified in curly brackets. The following variables are
# supported:
#
# {title}           Name of process as executed if parent, or type of child process.
# {listen-addr}     Bind address or '*' followed by TCP or TLS port listening on, or
#                   Unix socket if only that's available.
# {server-mode}     Special mode, i.e. "[sentinel]" or "[cluster]".
# {port}            TCP port listening on, or 0.
# {tls-port}        TLS port listening on, or 0.
# {unixsocket}      Unix domain socket listening on, or "".
# {config-file}     Name of configuration file used.
#
proc-title-template "{title} {listen-addr} {server-mode}"

配置项
daemonize no	Redis 默认不是以守护进程的方式运行，可以通过该配置项修改，使用 yes 启用守护进程（Windows 不支持守护线程的配置为 no ）
pidfile /var/run/redis.pid	以守护进程方式运行Redis时，pid文件配置，默认是：/var/run/redis.pid
loglevel notice	日志记录等级，有4个可选值，debug（开发），verbose（默认值），notice（生产），warning（警告）
logfile ""	日志文件的位置，当指定为空字符串时，为标准输出，如果redis已守护进程模式运行，那么日志将会输出到/dev/null，若指定了路径，日志将会输出到指定文件，默认值是""
databases 16	指定数据库数量，默认是16
always-show-logo no	是否展示ASCII码logo，默认yes
set-proc-title yes	默认情况下，Redis将流程标题（如“top”和“ps”中所示）修改为提供一些运行时信息。可以禁用此功能并离开通过将以下设置为“否”执行的进程名称。
syslog-enabled no	是否启动系统日志记录
syslog-ident redis	指定系统日志身份
syslog-facility local0	指定syslog设备。必须是user或LOCAL0 ~ LOCAL7之一
supervised no	是否通过upstart或systemd管理守护进程。默认no没有服务监控，其它选项有upstart, systemd, auto

SNAPSHOTTING快照

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

# Save the DB to disk.
#
# save <seconds> <changes>
#
# Redis will save the DB if both the given number of seconds and the given
# number of write operations against the DB occurred.
#
# Snapshotting can be completely disabled with a single empty string argument
# as in following example:
#
# save ""
#
# Unless specified otherwise, by default Redis will save the DB:
#   * After 3600 seconds (an hour) if at least 1 key changed
#   * After 300 seconds (5 minutes) if at least 100 keys changed
#   * After 60 seconds if at least 10000 keys changed
#
# You can set these explicitly by uncommenting the three following lines.
#
# save 3600 1
# save 300 100
# 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.
# 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?
# By default compression is enabled 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

# Enables or disables full sanitation checks for ziplist and listpack etc when
# loading an RDB or RESTORE payload. This reduces the chances of a assertion or
# crash later on while processing commands.
# Options:
#   no         - Never perform full sanitation
#   yes        - Always perform full sanitation
#   clients    - Perform full sanitation only for user connections.
#                Excludes: RDB files, RESTORE commands received from the master
#                connection, and client connections which have the
#                skip-sanitize-payload ACL flag.
# The default should be 'clients' but since it currently affects cluster
# resharding via MIGRATE, it is temporarily set to 'no' by default.
#
# sanitize-dump-payload no

# The filename where to dump the DB
dbfilename dump.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 ./

save 900 1 900秒（15分钟）之后，且至少1次变更

save 300 10 300秒（5分钟）之后，且至少10次变更

save 60 10000 60秒之后，且至少10000次变更

配置项
stop-writes-on-bgsave-error	默认情况下，如果 redis 最后一次的后台保存失败，redis 将停止接受写操作，这样以一种强硬的方式让 用户知道数据不能正确的持久化到磁盘， 否则就会没人注意到灾难的发生。 如果后台保存进程重新启动 工作了，redis 也将自动的允许写操作。默认值是yes
rdbcompression	当dump rdb数据库的时候，要不要进行压缩，如果你想节约CPU资源，可以设置为no，但那样的话，rdb数据 集将很大。默认是yes
rdbchecksum	从Redis5之后，一个CRC64校验和就被存在rdb文件的尾部，校验可以确认rdb文件的完整性，但是 它会占用10%左右的保存或加载rdb文件的资源，如果你为了让性能最大化，你可以设置为no，默认是yes
dbfilename dump.rdb	指定rdb文件的名称，默认是dump.rdb
rdb-del-sync-files	在没有持久性的情况下删除复制中使用的RDB文件，通常情况下保持默认即可
dir ./	本地数据库存放路径，默认值为./

SECURITY安全

################################## 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.

设置密码

127.0.0.1:6379> config get requirepass
1) "requirepass"
2) ""
127.0.0.1:6379> config set requirepass "123456"
OK
127.0.0.1:6379> exit
[root@VM-4-15-centos myredis]# redis
127.0.0.1:6379> keys *
(error) NOAUTH Authentication required.
127.0.0.1:6379> auth 123456
OK

MEMORY MANAGEMENT内存管理

############################## MEMORY MANAGEMENT ################################
# 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.

# 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

MAXMEMORY POLICY支持这几种过期策略

volatile-lru -> 对设置了过期时间的keys适用LRU淘汰策略
allkeys-lru -> 对所有keys适用LRU淘汰策略
volatile-lfu -> 对设置了过期时间的keys适用LFU淘汰策略
allkeys-lfu -> 对所有keys适用LFU淘汰策略
volatile-random -> 对设置了过期时间的keys适用随机淘汰策略
allkeys-random -> 对所有keys适用随机淘汰策略
volatile-ttl -> 淘汰离过期时间最近的keys
noeviction -> 不淘汰任何key，仅对写入操作返回一个错误 永不过期
maxmemory-policy noeviction 内存策略，默认是noeviction

maxmemory-samples：5

LRU,LFU,minimal TTL 算法都不是精准的算法，这里设置抽查的样本数量，默认是5个样本

CLIENTS 客户端

################################### CLIENTS ####################################
# maxclients 10000

客户端最大连接数配置默认是10000