Redis基础之配置文件

一般情况下，Redis配置文件中提供了很多默认的选项，可以不做任何修改而直接使用，本文主要简述配置文件中常用的配置选项，仅供学习分享使用，如有不足之处，还请指正。

Redis启动方式

Redis的启动时，必须有一个配置文件与之相匹配（如：/root/myredis/redis.conf），如下所示：

[root@localhost bin]# ./redis-server /root/myredis/redis.conf 

Redis配置文件详解

Redis配置文件项，主要分为以下几个部分：

1. INCLUDES：一个配置文件，可以导入其他配置文件。
2. MODULES：启动时加载的模块。
3. NETWORK：网络相关配置。
4. TLS/SSL：安全传输相关模块。
5. GENERAL：通用配置相关。
6. SNAPSHOTTING：快照配置相关。
7. REPLICATION：主从复制相关配置项。
8. KEYS TRACKING：键的追踪相关配置项。
9. SECURITY：安全相关配置。
10. CLIENTS：客户端相关配置。
11. MEMORY MANAGEMENT：内存管理相关配置项。
12. LAZY FREEING：延迟释放配置项。
13. THREADED I/O：多线程I/O相关配置项。
14. KERNEL OOM CONTROL：Linux内核防止内存占用过大配置选项。
15. APPEND ONLY MODE：数据持久化追加模式。
16. LUA SCRIPTING：Lua脚本相关配置项。
17. REDIS CLUSTER：Redis集群相关配置项。
18. CLUSTER DOCKER/NAT support：Docker/Nat集群支持配置项。
19. SLOW LOG：耗时日志。
20. LATENCY MONITOR：延迟监控配置相关选项。
21. EVENT NOTIFICATION：事件通知相关配置项。
22. GOPHER SERVER：Gopher服务器。
23. ADVANCED CONFIG：高级配置。
24. ACTIVE DEFRAGMENTATION：活动碎片整理相关配置。

说明：Redis配置文件，以# 开头，表示注释或者说明；如启用，则将#去掉即可。

INCLUDES

如果redis启动时有一个标准的配置模板，但是又需要自定义每一个实例的相关配置，则可以采用include 配置文件的方式导入。默认不需要导入文件，则此处是注释的。如下所示：

# include /path/to/local.conf
# include /path/to/other.conf

MODULES

启动时加载需要启动的模块，默认不需要启动，所以也是注释的。如下所示：

# loadmodule /path/to/my_module.so
# loadmodule /path/to/other_module.so

NETWORK

NETWORK主要用于配置网络相关的项，具体如下所示：

bind配置可以访问的ip地址，可以配置多个，一般建议局域网内部ip。如果是在internet下运行redis，并绑定了所有的ip地址，则是非常危险的操作。

如果需要所有ip都可以访问，则可以注释掉下面的语句。如下所示：

# Examples:
#
# bind 192.168.1.100 10.0.0.1
# bind 127.0.0.1 ::1

bind 127.0.0.1

port指定redis启动时的端口号，默认6379，不建议使用1000以下的端口号，因为容易与操作系统端口号引起冲突。如下所示：

# 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 6379

tcp-backlog配置完整连接队列的大小，默认511，但是此值一般不能大于/proc/sys/net/core/somaxconn 配置的值。如下所示：

# In high requests-per-second environments you need a high backlog in order
# to avoid slow clients connection 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

关于/proc/sys/net/core/somaxconn的值，如下所示：

[root@localhost bin]# cat /proc/sys/net/core/somaxconn
128

timeout设置超时时间，用于设置客户端多久没连接则断开连接人时间，0表示失效。如下所示：

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

tcp-keepalive设置保持连接时长，超过时间，则发送TCP ACK到客户端，如下所示：

# A reasonable value for this option is 300 seconds, which is the new
# Redis default starting with Redis 3.2.1.
tcp-keepalive 300

GENERAL

daemonize用于配置redis是否以守护进程运行，默认为no，启动时会单独启动一个窗口，当窗口关闭时，redis进程结束。所以为了让redis在后台运行，需要将此项改为yes。如下所示：

# 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

pidfile配置进程文件，当redis以守护进行启动时，会在启动时生成，关闭时删除启动文件，如下所示：

# 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

loglevel日志等级，共四种等级：debug，verbose，notice，warning默认为notice，如下所示：

# 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

logfile日志文件配置，默认为空，则不记录日志，如下所示：

# 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 ""

syslog-enabled是否记录系统日志，默认不记录，如下所示：

# 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

databases数据库个数，redis默认共有16个数据库，默认是0，如下所示：

# 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

always-show-logo设置logo是否显示，默认为yes，如下所示：

# 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

快照主要用于将内存中的数据保存到硬盘上。

save命令，配置多久保存一次，可以设置多种模式，如下所示：

# 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 behavior 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

save 900 1
save 300 10
save 60 10000

stop-writes-on-bgsave-error 当正在保存或者错误时，是否停止写入，默认为yes，如下所示：

# 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

rdbcompression 快照文件是否压缩，如果不压缩，则数据库文件将会很大，如下所示：

# 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

dbfilename数据库文件名，默认为dump.rdb。如下所示：

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

dir数据库文件的保存目录，如下所示：

# 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 ./

SECURITY

requirepass设置默认用户登录的密码，默认无密码，如下所示：

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

CLIENTS

maxclients同一时间允许连接的最大客户端数，如下所示：

# 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'.
#
# maxclients 10000

当配置redis集群时，redis连接数和集群总线共享。

Redis命令模式配置

redis除了可以通过修改配置文件的方式变更配置项，也可以通过客户端进行修改。示例如下：

config get * 用于获取所有的配置项，如下所示：

127.0.0.1:6379> config get *
  1) "rdbchecksum"
  2) "yes"
  3) "daemonize"
  4) "yes"
  5) "io-threads-do-reads"
  6) "no"
  7) "lua-replicate-commands"
  8) "yes"
  9) "always-show-logo"
 10) "yes"
 11) "protected-mode"
 12) "yes"
 13) "rdbcompression"
 14) "yes"
 15) "rdb-del-sync-files"
 16) "no"
 17) "activerehashing"
 18) "yes"
 19) "stop-writes-on-bgsave-error"
 20) "yes"
 21) "dynamic-hz"
 22) "yes"
 23) "lazyfree-lazy-eviction"
 24) "no"
 25) "lazyfree-lazy-expire"
 26) "no"
 27) "lazyfree-lazy-server-del"
 28) "no"
 29) "lazyfree-lazy-user-del"
 30) "no"
 31) "repl-disable-tcp-nodelay"
 32) "no"
 33) "repl-diskless-sync"
 34) "no"
 35) "gopher-enabled"
 36) "no"
 37) "aof-rewrite-incremental-fsync"
 38) "yes"
 39) "no-appendfsync-on-rewrite"
 40) "no"
 41) "cluster-require-full-coverage"
 42) "yes"
 43) "rdb-save-incremental-fsync"
 44) "yes"
 45) "aof-load-truncated"
 46) "yes"
 47) "aof-use-rdb-preamble"
 48) "yes"
 49) "cluster-replica-no-failover"
 50) "no"
 51) "cluster-slave-no-failover"
 52) "no"
 53) "replica-lazy-flush"
 54) "no"
 55) "slave-lazy-flush"
 56) "no"
 57) "replica-serve-stale-data"
 58) "yes"
 59) "slave-serve-stale-data"
 60) "yes"
 61) "replica-read-only"
 62) "yes"
 63) "slave-read-only"
 64) "yes"
 65) "replica-ignore-maxmemory"
 66) "yes"
 67) "slave-ignore-maxmemory"
 68) "yes"
 69) "jemalloc-bg-thread"
 70) "yes"
 71) "activedefrag"
 72) "no"
 73) "syslog-enabled"
 74) "no"
 75) "cluster-enabled"
 76) "no"
 77) "appendonly"
 78) "no"
 79) "cluster-allow-reads-when-down"
 80) "no"
 81) "oom-score-adj"
 82) "no"
 83) "aclfile"
 84) ""
 85) "unixsocket"
 86) ""
 87) "pidfile"
 88) "/var/run/redis_6379.pid"
 89) "replica-announce-ip"
 90) ""
 91) "slave-announce-ip"
 92) ""
 93) "masteruser"
 94) ""
 95) "masterauth"
 96) ""
 97) "cluster-announce-ip"
 98) ""
 99) "syslog-ident"
100) "redis"
101) "dbfilename"
102) "dump.rdb"
103) "appendfilename"
104) "appendonly.aof"
105) "server_cpulist"
106) ""
107) "bio_cpulist"
108) ""
109) "aof_rewrite_cpulist"
110) ""
111) "bgsave_cpulist"
112) ""
113) "supervised"
114) "no"
115) "syslog-facility"
116) "local0"
117) "repl-diskless-load"
118) "disabled"
119) "loglevel"
120) "notice"
121) "maxmemory-policy"
122) "noeviction"
123) "appendfsync"
124) "everysec"
125) "databases"
126) "16"
127) "port"
128) "6379"
129) "io-threads"
130) "1"
131) "auto-aof-rewrite-percentage"
132) "100"
133) "cluster-replica-validity-factor"
134) "10"
135) "cluster-slave-validity-factor"
136) "10"
137) "list-max-ziplist-size"
138) "-2"
139) "tcp-keepalive"
140) "300"
141) "cluster-migration-barrier"
142) "1"
143) "active-defrag-cycle-min"
144) "1"
145) "active-defrag-cycle-max"
146) "25"
147) "active-defrag-threshold-lower"
148) "10"
149) "active-defrag-threshold-upper"
150) "100"
151) "lfu-log-factor"
152) "10"
153) "lfu-decay-time"
154) "1"
155) "replica-priority"
156) "100"
157) "slave-priority"
158) "100"
159) "repl-diskless-sync-delay"
160) "5"
161) "maxmemory-samples"
162) "5"
163) "timeout"
164) "0"
165) "replica-announce-port"
166) "0"
167) "slave-announce-port"
168) "0"
169) "tcp-backlog"
170) "511"
171) "cluster-announce-bus-port"
172) "0"
173) "cluster-announce-port"
174) "0"
175) "repl-timeout"
176) "60"
177) "repl-ping-replica-period"
178) "10"
179) "repl-ping-slave-period"
180) "10"
181) "list-compress-depth"
182) "0"
183) "rdb-key-save-delay"
184) "0"
185) "key-load-delay"
186) "0"
187) "active-expire-effort"
188) "1"
189) "hz"
190) "10"
191) "min-replicas-to-write"
192) "0"
193) "min-slaves-to-write"
194) "0"
195) "min-replicas-max-lag"
196) "10"
197) "min-slaves-max-lag"
198) "10"
199) "maxclients"
200) "10000"
201) "active-defrag-max-scan-fields"
202) "1000"
203) "slowlog-max-len"
204) "128"
205) "acllog-max-len"
206) "128"
207) "lua-time-limit"
208) "5000"
209) "cluster-node-timeout"
210) "15000"
211) "slowlog-log-slower-than"
212) "10000"
213) "latency-monitor-threshold"
214) "0"
215) "proto-max-bulk-len"
216) "536870912"
217) "stream-node-max-entries"
218) "100"
219) "repl-backlog-size"
220) "1048576"
221) "maxmemory"
222) "0"
223) "hash-max-ziplist-entries"
224) "512"
225) "set-max-intset-entries"
226) "512"
227) "zset-max-ziplist-entries"
228) "128"
229) "active-defrag-ignore-bytes"
230) "104857600"
231) "hash-max-ziplist-value"
232) "64"
233) "stream-node-max-bytes"
234) "4096"
235) "zset-max-ziplist-value"
236) "64"
237) "hll-sparse-max-bytes"
238) "3000"
239) "tracking-table-max-keys"
240) "1000000"
241) "repl-backlog-ttl"
242) "3600"
243) "auto-aof-rewrite-min-size"
244) "67108864"
245) "logfile"
246) ""
247) "client-query-buffer-limit"
248) "1073741824"
249) "watchdog-period"
250) "0"
251) "dir"
252) "/usr/local/redis/bin"
253) "save"
254) "900 1 300 10 60 10000"
255) "client-output-buffer-limit"
256) "normal 0 0 0 slave 268435456 67108864 60 pubsub 33554432 8388608 60"
257) "unixsocketperm"
258) "0"
259) "slaveof"
260) ""
261) "notify-keyspace-events"
262) ""
263) "bind"
264) "127.0.0.1"
265) "requirepass"
266) ""
267) "oom-score-adj-values"
268) "0 200 800"

config get setting-name，获取单独的配置项，如loglevel，如下所示：

127.0.0.1:6379> config get loglevel
1) "loglevel"
2) "notice"
127.0.0.1:6379> 

 config set setting-name setting-value的格式来设置项，如下所示：

127.0.0.1:6379> config set loglevel verbose
OK
127.0.0.1:6379> config get loglevel
1) "loglevel"
2) "verbose"
127.0.0.1:6379> 

本文主要简述常见配置，更多配置，可参考菜鸟教程。

备注

洞仙歌·冰肌玉骨

朝代：宋朝|作者：苏轼

仆七岁时，见眉州老尼，姓朱，忘其名，年九十岁。自言尝随其师入蜀主孟昶宫中，一日大热，蜀主与花蕊夫人夜纳凉摩诃池上，作一词，朱具能记之。

今四十年，朱已死久矣，人无知此词者，但记其首两句，暇日寻味，岂《洞仙歌》令乎？乃为足之云。

 

冰肌玉骨，自清凉无汗。

水殿风来暗香满。

绣帘开，一点明月窥人，人未寝，欹（qī）枕钗横鬓乱。

 

起来携素手，庭户无声，时见疏星渡河汉。

试问夜如何？

夜已三更，金波淡，玉绳低转。

但屈指西风几时来，

又不道流年暗中偷换。