1 ##redis配置详解 2 3 # Redis configuration file example. 4 # 5 # Note that in order to read the configuration file, Redis must be 6 # started with the file path as first argument: 7 # 8 # ./redis-server /path/to/redis.conf 9 10 # Note on units: when memory size is needed, it is possible to specify 11 # it in the usual form of 1k 5GB 4M and so forth: 12 # 13 # 1k => 1000 bytes 14 # 1kb => 1024 bytes 15 # 1m => 1000000 bytes 16 # 1mb => 1024*1024 bytes 17 # 1g => 1000000000 bytes 18 # 1gb => 1024*1024*1024 bytes 19 # 20 # units are case insensitive so 1GB 1Gb 1gB are all the same. 21 22 ################################## INCLUDES ################################### 23 ################################## 包含 ################################### 24 25 # Include one or more other config files here. This is useful if you 26 # have a standard template that goes to all Redis servers but also need 27 # to customize a few per-server settings. Include files can include 28 # other files, so use this wisely. 29 # 30 # Notice option "include" won't be rewritten by command "CONFIG REWRITE" 31 # from admin or Redis Sentinel. Since Redis always uses the last processed 32 # line as value of a configuration directive, you'd better put includes 33 # at the beginning of this file to avoid overwriting config change at runtime. 34 # 35 # If instead you are interested in using includes to override configuration 36 # options, it is better to use include as the last line. 37 # 38 # 假如说你有一个可用于所有的 redis server 的标准配置模板， 39 # 但针对某些 server 又需要一些个性化的设置， 40 # 你可以使用 include 来包含一些其他的配置文件，这对你来说是非常有用的。 41 # 42 # 但是要注意哦，include 是不能被 config rewrite 命令改写的 43 # 由于 redis 总是以最后的加工线作为一个配置指令值，所以你最好是把 include 放在这个文件的最前面， 44 # 以避免在运行时覆盖配置的改变，相反，你就把它放在后面 45 # include /path/to/local.conf 46 # include /path/to/other.conf 47 48 ################################ GENERAL ##################################### 49 ################################ 常用 ##################################### 50 51 # By default Redis does not run as a daemon. Use 'yes' if you need it. 52 # Note that Redis will write a pid file in /var/run/redis.pid when daemonized. 53 # 默认情况下 redis 不是作为守护进程运行的，如果你想让它在后台运行，你就把它改成 yes。 54 # 当redis作为守护进程运行的时候，它会写一个 pid 到 /var/run/redis.pid 文件里面。 55 daemonize yes 56 57 # When running daemonized, Redis writes a pid file in /var/run/redis.pid by 58 # default. You can specify a custom pid file location here. 59 # 当 Redis 以守护进程的方式运行的时候，Redis 默认会把 pid 文件放在/var/run/redis.pid 60 # 可配置到其他地址，当运行多个 redis 服务时，需要指定不同的 pid 文件和端口 61 # 指定存储Redis进程号的文件路径 62 pidfile /var/run/redis.pid 63 64 # Accept connections on the specified port, default is 6379. 65 # If port 0 is specified Redis will not listen on a TCP socket. 66 # 端口，默认端口是6379，生产环境中建议更改端口号，安全性更高 67 # 如果你设为 0 ，redis 将不在 socket 上监听任何客户端连接。 68 port 9966 69 70 # TCP listen() backlog. 71 # 72 # In high requests-per-second environments you need an high backlog in order 73 # to avoid slow clients connections issues. Note that the Linux kernel 74 # will silently truncate it to the value of /proc/sys/net/core/somaxconn so 75 # make sure to raise both the value of somaxconn and tcp_max_syn_backlog 76 # in order to get the desired effect. 77 # TCP 监听的最大容纳数量 78 # 此参数确定了TCP连接中已完成队列(完成三次握手之后)的长度， 79 # 当系统并发量大并且客户端速度缓慢的时候，你需要把这个值调高以避免客户端连接缓慢的问题。 80 # Linux 内核会一声不响的把这个值缩小成 /proc/sys/net/core/somaxconn 对应的值，默认是511，而Linux的默认参数值是128。 81 # 所以可以将这二个参数一起参考设定，你以便达到你的预期。 82 # 83 tcp-backlog 511 84 85 # By default Redis listens for connections from all the network interfaces 86 # available on the server. It is possible to listen to just one or multiple 87 # interfaces using the "bind" configuration directive, followed by one or 88 # more IP addresses. 89 # 90 # Examples: 91 # 92 # bind 192.168.1.100 10.0.0.1 93 # 有时候为了安全起见，redis一般都是监听127.0.0.1 但是有时候又有同网段能连接的需求，当然可以绑定0.0.0.0 用iptables来控制访问权限，或者设置redis访问密码来保证数据安全 94 95 # 不设置将处理所有请求,建议生产环境中设置，有个误区：bind是用来限制外网IP访问的，其实不是，限制外网ip访问可以通过iptables；如：-A INPUT -s 10.10.1.0/24 -p tcp -m state --state NEW -m tcp --dport 9966 -j ACCEPT ； 96 # 实际上，bind ip 绑定的是redis所在服务器网卡的ip，当然127.0.0.1也是可以的 97 #如果绑定一个外网ip，就会报错：Creating Server TCP listening socket xxx.xxx.xxx.xxx:9966: bind: Cannot assign requested address 98 99 # bind 127.0.0.1 100 bind 127.0.0.1 10.10.1.3 101 102 # 假设绑定是以上ip，使用 netstat -anp|grep 9966 会发现，这两个ip被bind，其中10.10.1.3是服务器网卡的ip 103 # tcp 0 0 10.10.1.3:9966 0.0.0.0:* LISTEN 11188/redis-server 104 # tcp 0 0 127.0.0.1:9966 0.0.0.0:* LISTEN 11188/redis-server 105 106 107 # Specify the path for the Unix socket that will be used to listen for 108 # incoming connections. There is no default, so Redis will not listen 109 # on a unix socket when not specified. 110 # 111 # unixsocket /tmp/redis.sock 112 # unixsocketperm 700 113 114 # Close the connection after a client is idle for N seconds (0 to disable) 115 # 客户端和Redis服务端的连接超时时间，默认是0，表示永不超时。 116 timeout 0 117 118 # TCP keepalive. 119 # 120 # If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence 121 # of communication. This is useful for two reasons: 122 # 123 # 1) Detect dead peers. 124 # 2) Take the connection alive from the point of view of network 125 # equipment in the middle. 126 # 127 # On Linux, the specified value (in seconds) is the period used to send ACKs. 128 # Note that to close the connection the double of the time is needed. 129 # On other kernels the period depends on the kernel configuration. 130 # 131 # A reasonable value for this option is 60 seconds. 132 133 # tcp 心跳包。 134 # 135 # 如果设置为非零，则在与客户端缺乏通讯的时候使用 SO_KEEPALIVE 发送 tcp acks 给客户端。 136 # 这个之所有有用，主要由两个原因： 137 # 138 # 1) 防止死的 peers 139 # 2) Take the connection alive from the point of view of network 140 # equipment in the middle. 141 # 142 # 推荐一个合理的值就是60秒 143 tcp-keepalive 0 144 145 # Specify the server verbosity level. 146 # This can be one of: 147 # debug (a lot of information, useful for development/testing) 148 # verbose (many rarely useful info, but not a mess like the debug level) 149 # notice (moderately verbose, what you want in production probably) 150 # warning (only very important / critical messages are logged) 151 # 日志记录等级，4个可选值debug,verbose,notice,warning 152 # 可以是下面的这些值： 153 # debug (适用于开发或测试阶段) 154 # verbose (many rarely useful info, but not a mess like the debug level) 155 # notice (适用于生产环境) 156 # warning (仅仅一些重要的消息被记录) 157 loglevel notice 158 159 # Specify the log file name. Also the empty string can be used to force 160 # Redis to log on the standard output. Note that if you use standard 161 # output for logging but daemonize, logs will be sent to /dev/null 162 #配置 log 文件地址,默认打印在命令行终端的窗口上，也可设为/dev/null屏蔽日志、 163 logfile "/data/logs/redis/redis.log" 164 165 # To enable logging to the system logger, just set 'syslog-enabled' to yes, 166 # and optionally update the other syslog parameters to suit your needs. 167 # 要想把日志记录到系统日志，就把它改成 yes， 168 # 也可以可选择性的更新其他的syslog 参数以达到你的要求 169 # syslog-enabled no 170 171 # Specify the syslog identity. 172 # 设置 syslog 的 identity。 173 # syslog-ident redis 174 175 # Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7. 176 # syslog-facility local0 177 178 # Set the number of databases. The default database is DB 0, you can select 179 # a different one on a per-connection basis using SELECT <dbid> where 180 # dbid is a number between 0 and 'databases'-1 181 # 可用的数据库数，默认值为16，默认数据库为0，数据库范围在0-（database-1）之间 182 databases 16 183 184 ################################ SNAPSHOTTING ################################ 185 ################################ 快照 ################################ 186 # 187 # Save the DB on disk: 188 # 189 # save <seconds> <changes> 190 # 191 # Will save the DB if both the given number of seconds and the given 192 # number of write operations against the DB occurred. 193 # 194 # In the example below the behaviour will be to save: 195 # after 900 sec (15 min) if at least 1 key changed 196 # after 300 sec (5 min) if at least 10 keys changed 197 # after 60 sec if at least 10000 keys changed 198 # 199 # Note: you can disable saving completely by commenting out all "save" lines. 200 # 201 # It is also possible to remove all the previously configured save 202 # points by adding a save directive with a single empty string argument 203 # like in the following example: 204 # 205 # save "" 206 # 在 900 秒内最少有 1 个 key 被改动，或者 300 秒内最少有 10 个 key 被改动，又或者 60 秒内最少有 1000 个 key 被改动，以上三个条件随便满足一个，就触发一次保存操作。 207 208 # if(在60秒之内有10000个keys发生变化时){ 209 # 进行镜像备份 210 # }else if(在300秒之内有10个keys发生了变化){ 211 # 进行镜像备份 212 # }else if(在900秒之内有1个keys发生了变化){ 213 # 进行镜像备份 214 # } 215 216 save 900 1 217 save 300 10 218 save 60 10000 219 220 # By default Redis will stop accepting writes if RDB snapshots are enabled 221 # (at least one save point) and the latest background save failed. 222 # This will make the user aware (in a hard way) that data is not persisting 223 # on disk properly, otherwise chances are that no one will notice and some 224 #:/ disaster will happen. 225 # 226 # If the background saving process will start working again Redis will 227 # automatically allow writes again. 228 # 229 # However if you have setup your proper monitoring of the Redis server 230 # and persistence, you may want to disable this feature so that Redis will 231 # continue to work as usual even if there are problems with disk, 232 # permissions, and so forth. 233 # 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， 234 # 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， 235 # 否则就会没人注意到灾难的发生。 236 # 237 # 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。 238 # 239 # 然而你要是安装了靠谱的监控，你可能不希望 redis 这样做，那你就改成 no 好 240 stop-writes-on-bgsave-error yes 241 242 # Compress string objects using LZF when dump .rdb databases? 243 # For default that's set to 'yes' as it's almost always a win. 244 # If you want to save some CPU in the saving child set it to 'no' but 245 # the dataset will likely be bigger if you have compressible values or keys. 246 # 在进行备份时,是否进行压缩 247 # 是否在 dump .rdb 数据库的时候使用 LZF 压缩字符串 248 # 默认都设为 yes 249 # 如果你希望保存子进程节省点 cpu ，你就设置它为 no ， 250 # 不过这个数据集可能就会比较大 251 rdbcompression yes 252 253 # Since version 5 of RDB a CRC64 checksum is placed at the end of the file. 254 # This makes the format more resistant to corruption but there is a performance 255 # hit to pay (around 10%) when saving and loading RDB files, so you can disable it 256 # for maximum performances. 257 # 258 # RDB files created with checksum disabled have a checksum of zero that will 259 # tell the loading code to skip the check. 260 # 读取和写入的时候是否支持CRC64校验，默认是开启的 261 rdbchecksum yes 262 263 # The filename where to dump the DB 264 # 备份文件的文件名 265 dbfilename dump.rdb 266 267 # The working directory. 268 # 269 # The DB will be written inside this directory, with the filename specified 270 # above using the 'dbfilename' configuration directive. 271 # 272 # The Append Only File will also be created inside this directory. 273 # 274 # Note that you must specify a directory here, not a file name. 275 # 数据库备份的文件放置的路径 276 # 路径跟文件名分开配置是因为 Redis 备份时，先会将当前数据库的状态写入到一个临时文件 277 # 等备份完成时，再把该临时文件替换为上面所指定的文件 278 # 而临时文件和上面所配置的备份文件都会放在这个指定的路径当中 279 # 默认值为 ./ 280 dir /data/data/redis/ 281 282 ################################# REPLICATION ################################# 283 ################################# 主从复制 ################################# 284 # Master-Slave replication. Use slaveof to make a Redis instance a copy of 285 # another Redis server. A few things to understand ASAP about Redis replication. 286 # 287 # 1) Redis replication is asynchronous, but you can configure a master to 288 # stop accepting writes if it appears to be not connected with at least 289 # a given number of slaves. 290 # 2) Redis slaves are able to perform a partial resynchronization with the 291 # master if the replication link is lost for a relatively small amount of 292 # time. You may want to configure the replication backlog size (see the next 293 # sections of this file) with a sensible value depending on your needs. 294 # 3) Replication is automatic and does not need user intervention. After a 295 # network partition slaves automatically try to reconnect to masters 296 # and resynchronize with them. 297 # 298 # 设置该数据库为其他数据库的从数据库 299 # slaveof <masterip> <masterport> 当本机为从服务时，设置主服务的IP及端口 300 # slaveof <masterip> <masterport> 301 302 # If the master is password protected (using the "requirepass" configuration 303 # directive below) it is possible to tell the slave to authenticate before 304 # starting the replication synchronization process, otherwise the master will 305 # refuse the slave request. 306 # 307 # 指定与主数据库连接时需要的密码验证 308 # masterauth <master-password> 当本机为从服务时，设置访问master服务器的密码 309 # masterauth <master-password> 310 311 # When a slave loses its connection with the master, or when the replication 312 # is still in progress, the slave can act in two different ways: 313 # 314 # 1) if slave-serve-stale-data is set to 'yes' (the default) the slave will 315 # still reply to client requests, possibly with out of date data, or the 316 # data set may just be empty if this is the first synchronization. 317 # 318 # 2) if slave-serve-stale-data is set to 'no' the slave will reply with 319 # an error "SYNC with master in progress" to all the kind of commands 320 # but to INFO and SLAVEOF. 321 # 322 # 当slave服务器和master服务器失去连接后，或者当数据正在复制传输的时候，如果此参数值设置“yes”，slave服务器可以继续接受客户端的请求，否则，会返回给请求的客户端如下信息“SYNC with master in progress”,除了INFO，SLAVEOF这两个命令 323 slave-serve-stale-data yes 324 325 # You can configure a slave instance to accept writes or not. Writing against 326 # a slave instance may be useful to store some ephemeral data (because data 327 # written on a slave will be easily deleted after resync with the master) but 328 # may also cause problems if clients are writing to it because of a 329 # misconfiguration. 330 # 331 # Since Redis 2.6 by default slaves are read-only. 332 # 333 # Note: read only slaves are not designed to be exposed to untrusted clients 334 # on the internet. It's just a protection layer against misuse of the instance. 335 # Still a read only slave exports by default all the administrative commands 336 # such as CONFIG, DEBUG, and so forth. To a limited extent you can improve 337 # security of read only slaves using 'rename-command' to shadow all the 338 # administrative / dangerous commands. 339 # 是否允许slave服务器节点只提供读服务 340 slave-read-only yes 341 342 # Replication SYNC strategy: disk or socket. 343 # 344 # ------------------------------------------------------- 345 # WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY 346 # ------------------------------------------------------- 347 # 348 # New slaves and reconnecting slaves that are not able to continue the replication 349 # process just receiving differences, need to do what is called a "full 350 # synchronization". An RDB file is transmitted from the master to the slaves. 351 # The transmission can happen in two different ways: 352 # 353 # 1) Disk-backed: The Redis master creates a new process that writes the RDB 354 # file on disk. Later the file is transferred by the parent 355 # process to the slaves incrementally. 356 # 2) Diskless: The Redis master creates a new process that directly writes the 357 # RDB file to slave sockets, without touching the disk at all. 358 # 359 # With disk-backed replication, while the RDB file is generated, more slaves 360 # can be queued and served with the RDB file as soon as the current child producing 361 # the RDB file finishes its work. With diskless replication instead once 362 # the transfer starts, new slaves arriving will be queued and a new transfer 363 # will start when the current one terminates. 364 # 365 # When diskless replication is used, the master waits a configurable amount of 366 # time (in seconds) before starting the transfer in the hope that multiple slaves 367 # will arrive and the transfer can be parallelized. 368 # 369 # With slow disks and fast (large bandwidth) networks, diskless replication 370 # works better. 371 repl-diskless-sync no 372 373 # When diskless replication is enabled, it is possible to configure the delay 374 # the server waits in order to spawn the child that transfers the RDB via socket 375 # to the slaves. 376 # 377 # This is important since once the transfer starts, it is not possible to serve 378 # new slaves arriving, that will be queued for the next RDB transfer, so the server 379 # waits a delay in order to let more slaves arrive. 380 # 381 # The delay is specified in seconds, and by default is 5 seconds. To disable 382 # it entirely just set it to 0 seconds and the transfer will start ASAP. 383 repl-diskless-sync-delay 5 384 385 # Slaves send PINGs to server in a predefined interval. It's possible to change 386 # this interval with the repl_ping_slave_period option. The default value is 10 387 # seconds. 388 # 389 # Slaves 在一个预定义的时间间隔内发送 ping 命令到 server 。 390 # 你可以改变这个时间间隔。默认为 10 秒。 391 # repl-ping-slave-period 10 392 393 # The following option sets the replication timeout for: 394 # 395 # 1) Bulk transfer I/O during SYNC, from the point of view of slave. 396 # 2) Master timeout from the point of view of slaves (data, pings). 397 # 3) Slave timeout from the point of view of masters (REPLCONF ACK pings). 398 # 399 # It is important to make sure that this value is greater than the value 400 # specified for repl-ping-slave-period otherwise a timeout will be detected 401 # every time there is low traffic between the master and the slave. 402 # 403 # 设置主从复制过期时间 404 # 这个值一定要比 repl-ping-slave-period 大 405 # repl-timeout 60 406 407 # Disable TCP_NODELAY on the slave socket after SYNC? 408 # 409 # If you select "yes" Redis will use a smaller number of TCP packets and 410 # less bandwidth to send data to slaves. But this can add a delay for 411 # the data to appear on the slave side, up to 40 milliseconds with 412 # Linux kernels using a default configuration. 413 # 414 # If you select "no" the delay for data to appear on the slave side will 415 # be reduced but more bandwidth will be used for replication. 416 # 417 # By default we optimize for low latency, but in very high traffic conditions 418 # or when the master and slaves are many hops away, turning this to "yes" may 419 # be a good idea. 420 # 指定向slave同步数据时，是否禁用socket的NO_DELAY选 项。若配置为“yes”，则禁用NO_DELAY，则TCP协议栈会合并小包统一发送，这样可以减少主从节点间的包数量并节省带宽，但会增加数据同步到 slave的时间。若配置为“no”，表明启用NO_DELAY，则TCP协议栈不会延迟小包的发送时机，这样数据同步的延时会减少，但需要更大的带宽。 通常情况下，应该配置为no以降低同步延时，但在主从节点间网络负载已经很高的情况下，可以配置为yes。 421 repl-disable-tcp-nodelay no 422 423 # Set the replication backlog size. The backlog is a buffer that accumulates 424 # slave data when slaves are disconnected for some time, so that when a slave 425 # wants to reconnect again, often a full resync is not needed, but a partial 426 # resync is enough, just passing the portion of data the slave missed while 427 # disconnected. 428 # 429 # The bigger the replication backlog, the longer the time the slave can be 430 # disconnected and later be able to perform a partial resynchronization. 431 # 432 # The backlog is only allocated once there is at least a slave connected. 433 # 434 # 设置主从复制容量大小。这个 backlog 是一个用来在 slaves 被断开连接时 435 # 存放 slave 数据的 buffer，所以当一个 slave 想要重新连接，通常不希望全部重新同步， 436 # 只是部分同步就够了，仅仅传递 slave 在断开连接时丢失的这部分数据。 437 # 438 # The biggest the replication backlog, the longer the time the slave can be 439 # disconnected and later be able to perform a partial resynchronization. 440 # 这个值越大，salve 可以断开连接的时间就越长。 441 442 # repl-backlog-size 1mb 443 444 # After a master has no longer connected slaves for some time, the backlog 445 # will be freed. The following option configures the amount of seconds that 446 # need to elapse, starting from the time the last slave disconnected, for 447 # the backlog buffer to be freed. 448 # 449 # A value of 0 means to never release the backlog. 450 # 451 # 在某些时候，master 不再连接 slaves，backlog 将被释放。 452 # 如果设置为 0 ，意味着绝不释放 backlog 。 453 # repl-backlog-ttl 3600 454 455 # The slave priority is an integer number published by Redis in the INFO output. 456 # It is used by Redis Sentinel in order to select a slave to promote into a 457 # master if the master is no longer working correctly. 458 # 459 # A slave with a low priority number is considered better for promotion, so 460 # for instance if there are three slaves with priority 10, 100, 25 Sentinel will 461 # pick the one with priority 10, that is the lowest. 462 # 463 # However a special priority of 0 marks the slave as not able to perform the 464 # role of master, so a slave with priority of 0 will never be selected by 465 # Redis Sentinel for promotion. 466 # 467 # By default the priority is 100. 468 # 指定slave的优先级。在不只1个slave存在的部署环境下，当master宕机时，Redis 469 # Sentinel会将priority值最小的slave提升为master。 470 # 这个值越小，就越会被优先选中，需要注意的是， 471 # 若该配置项为0，则对应的slave永远不会自动提升为master。 472 slave-priority 100 473 474 # It is possible for a master to stop accepting writes if there are less than 475 # N slaves connected, having a lag less or equal than M seconds. 476 # 477 # The N slaves need to be in "online" state. 478 # 479 # The lag in seconds, that must be <= the specified value, is calculated from 480 # the last ping received from the slave, that is usually sent every second. 481 # 482 # This option does not GUARANTEE that N replicas will accept the write, but 483 # will limit the window of exposure for lost writes in case not enough slaves 484 # are available, to the specified number of seconds 485 # 486 # For example to require at least 3 slaves with a lag <= 10 seconds use: 487 # 488 # min-slaves-to-write 3 489 # min-slaves-max-lag 10 490 # 491 # Setting one or the other to 0 disables the feature. 492 # 493 # By default min-slaves-to-write is set to 0 (feature disabled) and 494 # min-slaves-max-lag is set to 10. 495 496 ################################## SECURITY ################################### 497 ################################## 安全 ################################### 498 499 # Require clients to issue AUTH <PASSWORD> before processing any other 500 # commands. This might be useful in environments in which you do not trust 501 # others with access to the host running redis-server. 502 # 503 # This should stay commented out for backward compatibility and because most 504 # people do not need auth (e.g. they run their own servers). 505 # 506 # Warning: since Redis is pretty fast an outside user can try up to 507 # 150k passwords per second against a good box. This means that you should 508 # use a very strong password otherwise it will be very easy to break. 509 # 510 # 设置连接redis的密码 511 # redis速度相当快，一个外部用户在一秒钟进行150K次密码尝试，需指定强大的密码来防止暴力破解 512 requirepass set_enough_strong_passwd 513 514 # Command renaming. 515 # 516 # It is possible to change the name of dangerous commands in a shared 517 # environment. For instance the CONFIG command may be renamed into something 518 # hard to guess so that it will still be available for internal-use tools 519 # but not available for general clients. 520 # 521 # Example: 522 # 523 # rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52 524 # 525 # It is also possible to completely kill a command by renaming it into 526 # an empty string: 527 # 528 # rename-command CONFIG "" 529 # 530 # Please note that changing the name of commands that are logged into the 531 # AOF file or transmitted to slaves may cause problems. 532 # 重命名一些高危命令，用来禁止高危命令 533 rename-command FLUSHALL ZYzv6FOBdwflW2nX 534 rename-command CONFIG aI7zwm1GDzMMrEi 535 rename-command EVAL S9UHPKEpSvUJMM 536 rename-command FLUSHDB D60FPVDJuip7gy6l 537 538 ################################### LIMITS #################################### 539 ################################### 限制 #################################### 540 541 # Set the max number of connected clients at the same time. By default 542 # this limit is set to 10000 clients, however if the Redis server is not 543 # able to configure the process file limit to allow for the specified limit 544 # the max number of allowed clients is set to the current file limit 545 # minus 32 (as Redis reserves a few file descriptors for internal uses). 546 # 547 # Once the limit is reached Redis will close all the new connections sending 548 # an error 'max number of clients reached'. 549 # 550 # 限制同时连接的客户数量,默认是10000 551 # 当连接数超过这个值时，redis 将不再接收其他连接请求，客户端尝试连接时将收到 error 信息 552 # maxclients 10000 553 554 # Don't use more memory than the specified amount of bytes. 555 # When the memory limit is reached Redis will try to remove keys 556 # according to the eviction policy selected (see maxmemory-policy). 557 # 558 # If Redis can't remove keys according to the policy, or if the policy is 559 # set to 'noeviction', Redis will start to reply with errors to commands 560 # that would use more memory, like SET, LPUSH, and so on, and will continue 561 # to reply to read-only commands like GET. 562 # 563 # This option is usually useful when using Redis as an LRU cache, or to set 564 # a hard memory limit for an instance (using the 'noeviction' policy). 565 # 566 # WARNING: If you have slaves attached to an instance with maxmemory on, 567 # the size of the output buffers needed to feed the slaves are subtracted 568 # from the used memory count, so that network problems / resyncs will 569 # not trigger a loop where keys are evicted, and in turn the output 570 # buffer of slaves is full with DELs of keys evicted triggering the deletion 571 # of more keys, and so forth until the database is completely emptied. 572 # 573 # In short... if you have slaves attached it is suggested that you set a lower 574 # limit for maxmemory so that there is some free RAM on the system for slave 575 # output buffers (but this is not needed if the policy is 'noeviction'). 576 # 577 # 设置redis能够使用的最大内存。 578 # 达到最大内存设置后，Redis会先尝试清除已到期或即将到期的Key（设置过expire信息的key） 579 # 在删除时,按照过期时间进行删除，最早将要被过期的key将最先被删除 580 # 如果已到期或即将到期的key删光，仍进行set操作，那么将返回错误 581 # 此时redis将不再接收写请求,只接收get请求。 582 # maxmemory的设置比较适合于把redis当作于类似memcached 的缓存来使用 583 # maxmemory <bytes> 584 585 # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory 586 # is reached. You can select among five behaviors: 587 # 588 # volatile-lru -> remove the key with an expire set using an LRU algorithm 589 # allkeys-lru -> remove any key according to the LRU algorithm 590 # volatile-random -> remove a random key with an expire set 591 # allkeys-random -> remove a random key, any key 592 # volatile-ttl -> remove the key with the nearest expire time (minor TTL) 593 # noeviction -> don't expire at all, just return an error on write operations 594 # 595 # Note: with any of the above policies, Redis will return an error on write 596 # operations, when there are no suitable keys for eviction. 597 # 598 # At the date of writing these commands are: set setnx setex append 599 # incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd 600 # sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby 601 # zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby 602 # getset mset msetnx exec sort 603 # 604 # The default is: 605 # 606 # maxmemory-policy noeviction 607 608 # LRU and minimal TTL algorithms are not precise algorithms but approximated 609 # algorithms (in order to save memory), so you can tune it for speed or 610 # accuracy. For default Redis will check five keys and pick the one that was 611 # used less recently, you can change the sample size using the following 612 # configuration directive. 613 # 614 # The default of 5 produces good enough results. 10 Approximates very closely 615 # true LRU but costs a bit more CPU. 3 is very fast but not very accurate. 616 # 617 # maxmemory-samples 5 618 619 ############################## APPEND ONLY MODE ############################### 620 621 # By default Redis asynchronously dumps the dataset on disk. This mode is 622 # good enough in many applications, but an issue with the Redis process or 623 # a power outage may result into a few minutes of writes lost (depending on 624 # the configured save points). 625 # 626 # The Append Only File is an alternative persistence mode that provides 627 # much better durability. For instance using the default data fsync policy 628 # (see later in the config file) Redis can lose just one second of writes in a 629 # dramatic event like a server power outage, or a single write if something 630 # wrong with the Redis process itself happens, but the operating system is 631 # still running correctly. 632 # 633 # AOF and RDB persistence can be enabled at the same time without problems. 634 # If the AOF is enabled on startup Redis will load the AOF, that is the file 635 # with the better durability guarantees. 636 # 637 # Please check http://redis.io/topics/persistence for more information. 638 639 # redis 默认每次更新操作后会在后台异步的把数据库镜像备份到磁盘，但该备份非常耗时，且备份不宜太频繁 640 # redis 同步数据文件是按上面save条件来同步的 641 # 如果发生诸如拉闸限电、拔插头等状况,那么将造成比较大范围的数据丢失 642 # 所以redis提供了另外一种更加高效的数据库备份及灾难恢复方式 643 # 开启append only 模式后,redis 将每一次写操作请求都追加到appendonly.aof 文件中 644 # redis重新启动时,会从该文件恢复出之前的状态。 645 # 但可能会造成 appendonly.aof 文件过大，所以redis支持BGREWRITEAOF 指令，对appendonly.aof重新整理,默认是不开启的。 646 647 appendonly no 648 649 # The name of the append only file (default: "appendonly.aof") 650 # 默认为appendonly.aof。 651 appendfilename "appendonly.aof" 652 653 # The fsync() call tells the Operating System to actually write data on disk 654 # instead of waiting for more data in the output buffer. Some OS will really flush 655 # data on disk, some other OS will just try to do it ASAP. 656 # 657 # Redis supports three different modes: 658 # 659 # no: don't fsync, just let the OS flush the data when it wants. Faster. 660 # always: fsync after every write to the append only log. Slow, Safest. 661 # everysec: fsync only one time every second. Compromise. 662 # 663 # The default is "everysec", as that's usually the right compromise between 664 # speed and data safety. It's up to you to understand if you can relax this to 665 # "no" that will let the operating system flush the output buffer when 666 # it wants, for better performances (but if you can live with the idea of 667 # some data loss consider the default persistence mode that's snapshotting), 668 # or on the contrary, use "always" that's very slow but a bit safer than 669 # everysec. 670 # 671 # More details please check the following article: 672 # http://antirez.com/post/redis-persistence-demystified.html 673 # 674 # If unsure, use "everysec". 675 676 # 设置对 appendonly.aof 文件进行同步的频率,有三种选择always、everysec、no，默认是everysec表示每秒同步一次。 677 # always 表示每次有写操作都进行同步,everysec 表示对写操作进行累积,每秒同步一次。 678 # no表示等操作系统进行数据缓存同步到磁盘，都进行同步,everysec 表示对写操作进行累积,每秒同步一次 679 # appendfsync always 680 # appendfsync everysec 681 # appendfsync no 682 683 # When the AOF fsync policy is set to always or everysec, and a background 684 # saving process (a background save or AOF log background rewriting) is 685 # performing a lot of I/O against the disk, in some Linux configurations 686 # Redis may block too long on the fsync() call. Note that there is no fix for 687 # this currently, as even performing fsync in a different thread will block 688 # our synchronous write(2) call. 689 # 690 # In order to mitigate this problem it's possible to use the following option 691 # that will prevent fsync() from being called in the main process while a 692 # BGSAVE or BGREWRITEAOF is in progress. 693 # 694 # This means that while another child is saving, the durability of Redis is 695 # the same as "appendfsync none". In practical terms, this means that it is 696 # possible to lose up to 30 seconds of log in the worst scenario (with the 697 # default Linux settings). 698 # 699 # If you have latency problems turn this to "yes". Otherwise leave it as 700 # "no" that is the safest pick from the point of view of durability. 701 # 指定是否在后台aof文件rewrite期间调用fsync，默认为no，表示要调用fsync（无论后台是否有子进程在刷盘）。Redis在后台写RDB文件或重写afo文件期间会存在大量磁盘IO，此时，在某些linux系统中，调用fsync可能会阻塞。 702 no-appendfsync-on-rewrite yes 703 704 # Automatic rewrite of the append only file. 705 # Redis is able to automatically rewrite the log file implicitly calling 706 # BGREWRITEAOF when the AOF log size grows by the specified percentage. 707 # 708 # This is how it works: Redis remembers the size of the AOF file after the 709 # latest rewrite (if no rewrite has happened since the restart, the size of 710 # the AOF at startup is used). 711 # 712 # This base size is compared to the current size. If the current size is 713 # bigger than the specified percentage, the rewrite is triggered. Also 714 # you need to specify a minimal size for the AOF file to be rewritten, this 715 # is useful to avoid rewriting the AOF file even if the percentage increase 716 # is reached but it is still pretty small. 717 # 718 # Specify a percentage of zero in order to disable the automatic AOF 719 # rewrite feature. 720 # 指定Redis重写aof文件的条件，默认为100，表示与上次rewrite的aof文件大小相比，当前aof文件增长量超过上次afo文件大小的100%时，就会触发background rewrite。若配置为0，则会禁用自动rewrite 721 auto-aof-rewrite-percentage 100 722 723 # 指定触发rewrite的aof文件大小。若aof文件小于该值，即使当前文件的增量比例达到auto-aof-rewrite-percentage的配置值，也不会触发自动rewrite。即这两个配置项同时满足时，才会触发rewrite。 724 auto-aof-rewrite-min-size 64mb 725 726 # An AOF file may be found to be truncated at the end during the Redis 727 # startup process, when the AOF data gets loaded back into memory. 728 # This may happen when the system where Redis is running 729 # crashes, especially when an ext4 filesystem is mounted without the 730 # data=ordered option (however this can't happen when Redis itself 731 # crashes or aborts but the operating system still works correctly). 732 # 733 # Redis can either exit with an error when this happens, or load as much 734 # data as possible (the default now) and start if the AOF file is found 735 # to be truncated at the end. The following option controls this behavior. 736 # 737 # If aof-load-truncated is set to yes, a truncated AOF file is loaded and 738 # the Redis server starts emitting a log to inform the user of the event. 739 # Otherwise if the option is set to no, the server aborts with an error 740 # and refuses to start. When the option is set to no, the user requires 741 # to fix the AOF file using the "redis-check-aof" utility before to restart 742 # the server. 743 # 744 # Note that if the AOF file will be found to be corrupted in the middle 745 # the server will still exit with an error. This option only applies when 746 # Redis will try to read more data from the AOF file but not enough bytes 747 # will be found. 748 aof-load-truncated yes 749 750 ################################ LUA SCRIPTING ############################### 751 752 # Max execution time of a Lua script in milliseconds. 753 # 754 # If the maximum execution time is reached Redis will log that a script is 755 # still in execution after the maximum allowed time and will start to 756 # reply to queries with an error. 757 # 758 # When a long running script exceeds the maximum execution time only the 759 # SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be 760 # used to stop a script that did not yet called write commands. The second 761 # is the only way to shut down the server in the case a write command was 762 # already issued by the script but the user doesn't want to wait for the natural 763 # termination of the script. 764 # 765 # Set it to 0 or a negative value for unlimited execution without warnings. 766 # 一个Lua脚本最长的执行时间，单位为毫秒，如果为0或负数表示无限执行时间，默认为5000 767 lua-time-limit 5000 768 769 ################################ REDIS CLUSTER ############################### 770 # 771 # ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 772 # WARNING EXPERIMENTAL: Redis Cluster is considered to be stable code, however 773 # in order to mark it as "mature" we need to wait for a non trivial percentage 774 # of users to deploy it in production. 775 # ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 776 # 777 # Normal Redis instances can't be part of a Redis Cluster; only nodes that are 778 # started as cluster nodes can. In order to start a Redis instance as a 779 # cluster node enable the cluster support uncommenting the following: 780 # 781 # cluster-enabled yes 782 783 # Every cluster node has a cluster configuration file. This file is not 784 # intended to be edited by hand. It is created and updated by Redis nodes. 785 # Every Redis Cluster node requires a different cluster configuration file. 786 # Make sure that instances running in the same system do not have 787 # overlapping cluster configuration file names. 788 # 789 # cluster-config-file nodes-6379.conf 790 791 # Cluster node timeout is the amount of milliseconds a node must be unreachable 792 # for it to be considered in failure state. 793 # Most other internal time limits are multiple of the node timeout. 794 # 795 # cluster-node-timeout 15000 796 797 # A slave of a failing master will avoid to start a failover if its data 798 # looks too old. 799 # 800 # There is no simple way for a slave to actually have a exact measure of 801 # its "data age", so the following two checks are performed: 802 # 803 # 1) If there are multiple slaves able to failover, they exchange messages 804 # in order to try to give an advantage to the slave with the best 805 # replication offset (more data from the master processed). 806 # Slaves will try to get their rank by offset, and apply to the start 807 # of the failover a delay proportional to their rank. 808 # 809 # 2) Every single slave computes the time of the last interaction with 810 # its master. This can be the last ping or command received (if the master 811 # is still in the "connected" state), or the time that elapsed since the 812 # disconnection with the master (if the replication link is currently down). 813 # If the last interaction is too old, the slave will not try to failover 814 # at all. 815 # 816 # The point "2" can be tuned by user. Specifically a slave will not perform 817 # the failover if, since the last interaction with the master, the time 818 # elapsed is greater than: 819 # 820 # (node-timeout * slave-validity-factor) + repl-ping-slave-period 821 # 822 # So for example if node-timeout is 30 seconds, and the slave-validity-factor 823 # is 10, and assuming a default repl-ping-slave-period of 10 seconds, the 824 # slave will not try to failover if it was not able to talk with the master 825 # for longer than 310 seconds. 826 # 827 # A large slave-validity-factor may allow slaves with too old data to failover 828 # a master, while a too small value may prevent the cluster from being able to 829 # elect a slave at all. 830 # 831 # For maximum availability, it is possible to set the slave-validity-factor 832 # to a value of 0, which means, that slaves will always try to failover the 833 # master regardless of the last time they interacted with the master. 834 # (However they'll always try to apply a delay proportional to their 835 # offset rank). 836 # 837 # Zero is the only value able to guarantee that when all the partitions heal 838 # the cluster will always be able to continue. 839 # 840 # cluster-slave-validity-factor 10 841 842 # Cluster slaves are able to migrate to orphaned masters, that are masters 843 # that are left without working slaves. This improves the cluster ability 844 # to resist to failures as otherwise an orphaned master can't be failed over 845 # in case of failure if it has no working slaves. 846 # 847 # Slaves migrate to orphaned masters only if there are still at least a 848 # given number of other working slaves for their old master. This number 849 # is the "migration barrier". A migration barrier of 1 means that a slave 850 # will migrate only if there is at least 1 other working slave for its master 851 # and so forth. It usually reflects the number of slaves you want for every 852 # master in your cluster. 853 # 854 # Default is 1 (slaves migrate only if their masters remain with at least 855 # one slave). To disable migration just set it to a very large value. 856 # A value of 0 can be set but is useful only for debugging and dangerous 857 # in production. 858 # 859 # cluster-migration-barrier 1 860 861 # By default Redis Cluster nodes stop accepting queries if they detect there 862 # is at least an hash slot uncovered (no available node is serving it). 863 # This way if the cluster is partially down (for example a range of hash slots 864 # are no longer covered) all the cluster becomes, eventually, unavailable. 865 # It automatically returns available as soon as all the slots are covered again. 866 # 867 # However sometimes you want the subset of the cluster which is working, 868 # to continue to accept queries for the part of the key space that is still 869 # covered. In order to do so, just set the cluster-require-full-coverage 870 # option to no. 871 # 872 # cluster-require-full-coverage yes 873 874 # In order to setup your cluster make sure to read the documentation 875 # available at http://redis.io web site. 876 877 ################################## SLOW LOG ################################### 878 879 # The Redis Slow Log is a system to log queries that exceeded a specified 880 # execution time. The execution time does not include the I/O operations 881 # like talking with the client, sending the reply and so forth, 882 # but just the time needed to actually execute the command (this is the only 883 # stage of command execution where the thread is blocked and can not serve 884 # other requests in the meantime). 885 # 886 # You can configure the slow log with two parameters: one tells Redis 887 # what is the execution time, in microseconds, to exceed in order for the 888 # command to get logged, and the other parameter is the length of the 889 # slow log. When a new command is logged the oldest one is removed from the 890 # queue of logged commands. 891 892 # The following time is expressed in microseconds, so 1000000 is equivalent 893 # to one second. Note that a negative number disables the slow log, while 894 # a value of zero forces the logging of every command. 895 slowlog-log-slower-than 10000 896 897 # There is no limit to this length. Just be aware that it will consume memory. 898 # You can reclaim memory used by the slow log with SLOWLOG RESET. 899 slowlog-max-len 128 900 901 ################################ LATENCY MONITOR ############################## 902 903 # The Redis latency monitoring subsystem samples different operations 904 # at runtime in order to collect data related to possible sources of 905 # latency of a Redis instance. 906 # 907 # Via the LATENCY command this information is available to the user that can 908 # print graphs and obtain reports. 909 # 910 # The system only logs operations that were performed in a time equal or 911 # greater than the amount of milliseconds specified via the 912 # latency-monitor-threshold configuration directive. When its value is set 913 # to zero, the latency monitor is turned off. 914 # 915 # By default latency monitoring is disabled since it is mostly not needed 916 # if you don't have latency issues, and collecting data has a performance 917 # impact, that while very small, can be measured under big load. Latency 918 # monitoring can easily be enabled at runtime using the command 919 # "CONFIG SET latency-monitor-threshold <milliseconds>" if needed. 920 latency-monitor-threshold 0 921 922 ############################# EVENT NOTIFICATION ############################## 923 924 # Redis can notify Pub/Sub clients about events happening in the key space. 925 # This feature is documented at http://redis.io/topics/notifications 926 # 927 # For instance if keyspace events notification is enabled, and a client 928 # performs a DEL operation on key "foo" stored in the Database 0, two 929 # messages will be published via Pub/Sub: 930 # 931 # PUBLISH __keyspace@0__:foo del 932 # PUBLISH __keyevent@0__:del foo 933 # 934 # It is possible to select the events that Redis will notify among a set 935 # of classes. Every class is identified by a single character: 936 # 937 # K Keyspace events, published with __keyspace@<db>__ prefix. 938 # E Keyevent events, published with __keyevent@<db>__ prefix. 939 # g Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ... 940 # $ String commands 941 # l List commands 942 # s Set commands 943 # h Hash commands 944 # z Sorted set commands 945 # x Expired events (events generated every time a key expires) 946 # e Evicted events (events generated when a key is evicted for maxmemory) 947 # A Alias for g$lshzxe, so that the "AKE" string means all the events. 948 # 949 # The "notify-keyspace-events" takes as argument a string that is composed 950 # of zero or multiple characters. The empty string means that notifications 951 # are disabled. 952 # 953 # Example: to enable list and generic events, from the point of view of the 954 # event name, use: 955 # 956 # notify-keyspace-events Elg 957 # 958 # Example 2: to get the stream of the expired keys subscribing to channel 959 # name __keyevent@0__:expired use: 960 # 961 # notify-keyspace-events Ex 962 # 963 # By default all notifications are disabled because most users don't need 964 # this feature and the feature has some overhead. Note that if you don't 965 # specify at least one of K or E, no events will be delivered. 966 notify-keyspace-events "" 967 968 ############################### ADVANCED CONFIG ############################### 969 970 # Hashes are encoded using a memory efficient data structure when they have a 971 # small number of entries, and the biggest entry does not exceed a given 972 # threshold. These thresholds can be configured using the following directives. 973 # 当hash中包含超过指定元素个数并且最大的元素没有超过临界时， 974 # hash将以一种特殊的编码方式（大大减少内存使用）来存储，这里可以设置这两个临界值 975 hash-max-ziplist-entries 512 976 hash-max-ziplist-value 64 977 978 # Similarly to hashes, small lists are also encoded in a special way in order 979 # to save a lot of space. The special representation is only used when 980 # you are under the following limits: 981 # list数据类型多少节点以下会采用去指针的紧凑存储格式。 982 # list数据类型节点值大小小于多少字节会采用紧凑存储格式。 983 list-max-ziplist-entries 512 984 list-max-ziplist-value 64 985 986 # Sets have a special encoding in just one case: when a set is composed 987 # of just strings that happen to be integers in radix 10 in the range 988 # of 64 bit signed integers. 989 # The following configuration setting sets the limit in the size of the 990 # set in order to use this special memory saving encoding. 991 # set数据类型内部数据如果全部是数值型，且包含多少节点以下会采用紧凑格式存储。 992 set-max-intset-entries 512 993 994 # Similarly to hashes and lists, sorted sets are also specially encoded in 995 # order to save a lot of space. This encoding is only used when the length and 996 # elements of a sorted set are below the following limits: 997 998 # zsort数据类型多少节点以下会采用去指针的紧凑存储格式。 999 # zsort数据类型节点值大小小于多少字节会采用紧凑存储格式。 1000 zset-max-ziplist-entries 128 1001 zset-max-ziplist-value 64 1002 1003 # HyperLogLog sparse representation bytes limit. The limit includes the 1004 # 16 bytes header. When an HyperLogLog using the sparse representation crosses 1005 # this limit, it is converted into the dense representation. 1006 # 1007 # A value greater than 16000 is totally useless, since at that point the 1008 # dense representation is more memory efficient. 1009 # 1010 # The suggested value is ~ 3000 in order to have the benefits of 1011 # the space efficient encoding without slowing down too much PFADD, 1012 # which is O(N) with the sparse encoding. The value can be raised to 1013 # ~ 10000 when CPU is not a concern, but space is, and the data set is 1014 # composed of many HyperLogLogs with cardinality in the 0 - 15000 range. 1015 hll-sparse-max-bytes 3000 1016 1017 # Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in 1018 # order to help rehashing the main Redis hash table (the one mapping top-level 1019 # keys to values). The hash table implementation Redis uses (see dict.c) 1020 # performs a lazy rehashing: the more operation you run into a hash table 1021 # that is rehashing, the more rehashing "steps" are performed, so if the 1022 # server is idle the rehashing is never complete and some more memory is used 1023 # by the hash table. 1024 # 1025 # The default is to use this millisecond 10 times every second in order to 1026 # actively rehash the main dictionaries, freeing memory when possible. 1027 # 1028 # If unsure: 1029 # use "activerehashing no" if you have hard latency requirements and it is 1030 # not a good thing in your environment that Redis can reply from time to time 1031 # to queries with 2 milliseconds delay. 1032 # 1033 # use "activerehashing yes" if you don't have such hard requirements but 1034 # want to free memory asap when possible. 1035 1036 # Redis将在每100毫秒时使用1毫秒的CPU时间来对redis的hash表进行重新hash，可以降低内存的使用 1037 # 当你的使用场景中，有非常严格的实时性需要，不能够接受Redis时不时的对请求有2毫秒的延迟的话，把这项配置为no。 1038 # 如果没有这么严格的实时性要求，可以设置为yes，以便能够尽可能快的释放内存 1039 activerehashing yes 1040 1041 # The client output buffer limits can be used to force disconnection of clients 1042 # that are not reading data from the server fast enough for some reason (a 1043 # common reason is that a Pub/Sub client can't consume messages as fast as the 1044 # publisher can produce them). 1045 # 1046 # The limit can be set differently for the three different classes of clients: 1047 # 1048 # normal -> normal clients including MONITOR clients 1049 # slave -> slave clients 1050 # pubsub -> clients subscribed to at least one pubsub channel or pattern 1051 # 1052 # The syntax of every client-output-buffer-limit directive is the following: 1053 # 1054 # client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds> 1055 # 1056 # A client is immediately disconnected once the hard limit is reached, or if 1057 # the soft limit is reached and remains reached for the specified number of 1058 # seconds (continuously). 1059 # So for instance if the hard limit is 32 megabytes and the soft limit is 1060 # 16 megabytes / 10 seconds, the client will get disconnected immediately 1061 # if the size of the output buffers reach 32 megabytes, but will also get 1062 # disconnected if the client reaches 16 megabytes and continuously overcomes 1063 # the limit for 10 seconds. 1064 # 1065 # By default normal clients are not limited because they don't receive data 1066 # without asking (in a push way), but just after a request, so only 1067 # asynchronous clients may create a scenario where data is requested faster 1068 # than it can read. 1069 # 1070 # Instead there is a default limit for pubsub and slave clients, since 1071 # subscribers and slaves receive data in a push fashion. 1072 # 1073 # Both the hard or the soft limit can be disabled by setting them to zero. 1074 client-output-buffer-limit normal 0 0 0 1075 client-output-buffer-limit slave 256mb 64mb 60 1076 client-output-buffer-limit pubsub 32mb 8mb 60 1077 1078 # Redis calls an internal function to perform many background tasks, like 1079 # closing connections of clients in timeout, purging expired keys that are 1080 # never requested, and so forth. 1081 # 1082 # Not all tasks are performed with the same frequency, but Redis checks for 1083 # tasks to perform according to the specified "hz" value. 1084 # 1085 # By default "hz" is set to 10. Raising the value will use more CPU when 1086 # Redis is idle, but at the same time will make Redis more responsive when 1087 # there are many keys expiring at the same time, and timeouts may be 1088 # handled with more precision. 1089 # 1090 # The range is between 1 and 500, however a value over 100 is usually not 1091 # a good idea. Most users should use the default of 10 and raise this up to 1092 # 100 only in environments where very low latency is required. 1093 hz 10 1094 1095 # When a child rewrites the AOF file, if the following option is enabled 1096 # the file will be fsync-ed every 32 MB of data generated. This is useful 1097 # in order to commit the file to the disk more incrementally and avoid 1098 # big latency spikes. 1099 # aof rewrite过程中,是否采取增量文件同步策略,默认为“yes”。 rewrite过程中,每32M数据进行一次文件同步,这样可以减少aof大文件写入对磁盘的操作次数 1100 aof-rewrite-incremental-fsync yes 1101 1102 1103 # redis数据存储 1104 redis的存储分为内存存储、磁盘存储和log文件三部分，配置文件中有三个参数对其进行配置。 1105 save seconds updates，save配置，指出在多长时间内，有多少次更新操作，就将数据同步到数据文件。可多个条件配合，默认配置了三个条件。 1106 appendonly yes/no ，appendonly配置，指出是否在每次更新操作后进行日志记录，如果不开启，可能会在断电时导致一段时间内的数据丢失。因为redis本身同步数据文件是按上面的save条件来同步的，所以有的数据会在一段时间内只存在于内存中。 1107 appendfsync no/always/everysec ，appendfsync配置，no表示等操作系统进行数据缓存同步到磁盘，always表示每次更新操作后手动调用fsync()将数据写到磁盘，everysec表示每秒同步一次。
##redis配置详解
# 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 ##################################################################### 包含 ###################################
# 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.## 假如说你有一个可用于所有的 redis server 的标准配置模板，# 但针对某些 server 又需要一些个性化的设置，# 你可以使用 include 来包含一些其他的配置文件，这对你来说是非常有用的。## 但是要注意哦，include 是不能被 config rewrite 命令改写的# 由于 redis 总是以最后的加工线作为一个配置指令值，所以你最好是把 include 放在这个文件的最前面，# 以避免在运行时覆盖配置的改变，相反，你就把它放在后面# include /path/to/local.conf# include /path/to/other.conf
################################ GENERAL ##################################################################### 常用 #####################################
# 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.# 默认情况下 redis 不是作为守护进程运行的，如果你想让它在后台运行，你就把它改成 yes。# 当redis作为守护进程运行的时候，它会写一个 pid 到 /var/run/redis.pid 文件里面。daemonize yes
# When running daemonized, Redis writes a pid file in /var/run/redis.pid by# default. You can specify a custom pid file location here.# 当 Redis 以守护进程的方式运行的时候，Redis 默认会把 pid 文件放在/var/run/redis.pid# 可配置到其他地址，当运行多个 redis 服务时，需要指定不同的 pid 文件和端口# 指定存储Redis进程号的文件路径pidfile /var/run/redis.pid
# Accept connections on the specified port, default is 6379.# If port 0 is specified Redis will not listen on a TCP socket.# 端口，默认端口是6379，生产环境中建议更改端口号，安全性更高# 如果你设为 0 ，redis 将不在 socket 上监听任何客户端连接。port 9966
# 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 监听的最大容纳数量# 此参数确定了TCP连接中已完成队列(完成三次握手之后)的长度，# 当系统并发量大并且客户端速度缓慢的时候，你需要把这个值调高以避免客户端连接缓慢的问题。# Linux 内核会一声不响的把这个值缩小成 /proc/sys/net/core/somaxconn 对应的值，默认是511，而Linux的默认参数值是128。# 所以可以将这二个参数一起参考设定，你以便达到你的预期。# tcp-backlog 511
# By default Redis listens for connections from all the network interfaces# available on the server. It is possible to listen to just one or multiple# interfaces using the "bind" configuration directive, followed by one or# more IP addresses.## Examples:## bind 192.168.1.100 10.0.0.1# 有时候为了安全起见，redis一般都是监听127.0.0.1 但是有时候又有同网段能连接的需求，当然可以绑定0.0.0.0 用iptables来控制访问权限，或者设置redis访问密码来保证数据安全
# 不设置将处理所有请求,建议生产环境中设置，有个误区：bind是用来限制外网IP访问的，其实不是，限制外网ip访问可以通过iptables；如：-A INPUT -s 10.10.1.0/24 -p tcp -m state --state NEW -m tcp --dport 9966 -j ACCEPT ；# 实际上，bind ip 绑定的是redis所在服务器网卡的ip，当然127.0.0.1也是可以的#如果绑定一个外网ip，就会报错：Creating Server TCP listening socket xxx.xxx.xxx.xxx:9966: bind: Cannot assign requested address
# bind 127.0.0.1bind 127.0.0.1 10.10.1.3
# 假设绑定是以上ip，使用 netstat -anp|grep 9966 会发现，这两个ip被bind，其中10.10.1.3是服务器网卡的ip# tcp 0 0 10.10.1.3:9966 0.0.0.0:* LISTEN 11188/redis-server # tcp 0 0 127.0.0.1:9966 0.0.0.0:* LISTEN 11188/redis-server
# 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)# 客户端和Redis服务端的连接超时时间，默认是0，表示永不超时。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 60 seconds.
# tcp 心跳包。## 如果设置为非零，则在与客户端缺乏通讯的时候使用 SO_KEEPALIVE 发送 tcp acks 给客户端。# 这个之所有有用，主要由两个原因：## 1) 防止死的 peers# 2) Take the connection alive from the point of view of network# equipment in the middle.## 推荐一个合理的值就是60秒tcp-keepalive 0
# 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)# 日志记录等级，4个可选值debug,verbose,notice,warning# 可以是下面的这些值：# debug (适用于开发或测试阶段)# verbose (many rarely useful info, but not a mess like the debug level)# notice (适用于生产环境)# warning (仅仅一些重要的消息被记录)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#配置 log 文件地址,默认打印在命令行终端的窗口上，也可设为/dev/null屏蔽日志、logfile "/data/logs/redis/redis.log"
# To enable logging to the system logger, just set 'syslog-enabled' to yes,# and optionally update the other syslog parameters to suit your needs.# 要想把日志记录到系统日志，就把它改成 yes，# 也可以可选择性的更新其他的syslog 参数以达到你的要求# syslog-enabled no
# Specify the syslog identity.# 设置 syslog 的 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# 可用的数据库数，默认值为16，默认数据库为0，数据库范围在0-（database-1）之间databases 16
################################ SNAPSHOTTING ################################################################ 快照 ################################## 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 ""# 在 900 秒内最少有 1 个 key 被改动，或者 300 秒内最少有 10 个 key 被改动，又或者 60 秒内最少有 1000 个 key 被改动，以上三个条件随便满足一个，就触发一次保存操作。
# if(在60秒之内有10000个keys发生变化时){# 进行镜像备份# }else if(在300秒之内有10个keys发生了变化){# 进行镜像备份# }else if(在900秒之内有1个keys发生了变化){# 进行镜像备份# }
save 900 1save 300 10save 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.# 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。## 然而你要是安装了靠谱的监控，你可能不希望 redis 这样做，那你就改成 no 好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.# 在进行备份时,是否进行压缩# 是否在 dump .rdb 数据库的时候使用 LZF 压缩字符串# 默认都设为 yes# 如果你希望保存子进程节省点 cpu ，你就设置它为 no ，# 不过这个数据集可能就会比较大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. # 读取和写入的时候是否支持CRC64校验，默认是开启的rdbchecksum yes
# The filename where to dump the DB# 备份文件的文件名dbfilename dump.rdb
# 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.# 数据库备份的文件放置的路径# 路径跟文件名分开配置是因为 Redis 备份时，先会将当前数据库的状态写入到一个临时文件# 等备份完成时，再把该临时文件替换为上面所指定的文件# 而临时文件和上面所配置的备份文件都会放在这个指定的路径当中# 默认值为 ./dir /data/data/redis/
################################# REPLICATION ################################################################## 主从复制 ################################## Master-Slave replication. Use slaveof to make a Redis instance a copy of# another Redis server. A few things to understand ASAP about Redis replication.## 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 slaves.# 2) Redis slaves 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 slaves automatically try to reconnect to masters# and resynchronize with them.## 设置该数据库为其他数据库的从数据库# slaveof <masterip> <masterport> 当本机为从服务时，设置主服务的IP及端口# slaveof <masterip> <masterport>
# If the master is password protected (using the "requirepass" configuration# directive below) it is possible to tell the slave to authenticate before# starting the replication synchronization process, otherwise the master will# refuse the slave request.## 指定与主数据库连接时需要的密码验证# masterauth <master-password> 当本机为从服务时，设置访问master服务器的密码# masterauth <master-password>
# When a slave loses its connection with the master, or when the replication# is still in progress, the slave can act in two different ways:## 1) if slave-serve-stale-data is set to 'yes' (the default) the slave 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 slave-serve-stale-data is set to 'no' the slave will reply with# an error "SYNC with master in progress" to all the kind of commands# but to INFO and SLAVEOF.## 当slave服务器和master服务器失去连接后，或者当数据正在复制传输的时候，如果此参数值设置“yes”，slave服务器可以继续接受客户端的请求，否则，会返回给请求的客户端如下信息“SYNC with master in progress”,除了INFO，SLAVEOF这两个命令slave-serve-stale-data yes
# You can configure a slave instance to accept writes or not. Writing against# a slave instance may be useful to store some ephemeral data (because data# written on a slave 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 slaves are read-only.## Note: read only slaves 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 slave 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 slaves using 'rename-command' to shadow all the# administrative / dangerous commands.# 是否允许slave服务器节点只提供读服务slave-read-only yes
# Replication SYNC strategy: disk or socket.## -------------------------------------------------------# WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY# -------------------------------------------------------## New slaves and reconnecting slaves 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 slaves.# 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 slaves incrementally.# 2) Diskless: The Redis master creates a new process that directly writes the# RDB file to slave sockets, without touching the disk at all.## With disk-backed replication, while the RDB file is generated, more slaves# 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 slaves 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 slaves# 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 slaves.## This is important since once the transfer starts, it is not possible to serve# new slaves arriving, that will be queued for the next RDB transfer, so the server# waits a delay in order to let more slaves 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
# Slaves send PINGs to server in a predefined interval. It's possible to change# this interval with the repl_ping_slave_period option. The default value is 10# seconds.## Slaves 在一个预定义的时间间隔内发送 ping 命令到 server 。# 你可以改变这个时间间隔。默认为 10 秒。# repl-ping-slave-period 10
# The following option sets the replication timeout for:## 1) Bulk transfer I/O during SYNC, from the point of view of slave.# 2) Master timeout from the point of view of slaves (data, pings).# 3) Slave 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-slave-period otherwise a timeout will be detected# every time there is low traffic between the master and the slave.## 设置主从复制过期时间# 这个值一定要比 repl-ping-slave-period 大# repl-timeout 60
# Disable TCP_NODELAY on the slave socket after SYNC?## If you select "yes" Redis will use a smaller number of TCP packets and# less bandwidth to send data to slaves. But this can add a delay for# the data to appear on the slave side, up to 40 milliseconds with# Linux kernels using a default configuration.## If you select "no" the delay for data to appear on the slave 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 slaves are many hops away, turning this to "yes" may# be a good idea.# 指定向slave同步数据时，是否禁用socket的NO_DELAY选 项。若配置为“yes”，则禁用NO_DELAY，则TCP协议栈会合并小包统一发送，这样可以减少主从节点间的包数量并节省带宽，但会增加数据同步到 slave的时间。若配置为“no”，表明启用NO_DELAY，则TCP协议栈不会延迟小包的发送时机，这样数据同步的延时会减少，但需要更大的带宽。 通常情况下，应该配置为no以降低同步延时，但在主从节点间网络负载已经很高的情况下，可以配置为yes。repl-disable-tcp-nodelay no
# Set the replication backlog size. The backlog is a buffer that accumulates# slave data when slaves are disconnected for some time, so that when a slave# wants to reconnect again, often a full resync is not needed, but a partial# resync is enough, just passing the portion of data the slave missed while# disconnected.## The bigger the replication backlog, the longer the time the slave can be# disconnected and later be able to perform a partial resynchronization.## The backlog is only allocated once there is at least a slave connected.## 设置主从复制容量大小。这个 backlog 是一个用来在 slaves 被断开连接时# 存放 slave 数据的 buffer，所以当一个 slave 想要重新连接，通常不希望全部重新同步，# 只是部分同步就够了，仅仅传递 slave 在断开连接时丢失的这部分数据。## The biggest the replication backlog, the longer the time the slave can be# disconnected and later be able to perform a partial resynchronization.# 这个值越大，salve 可以断开连接的时间就越长。
# repl-backlog-size 1mb
# After a master has no longer connected slaves 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 slave disconnected, for# the backlog buffer to be freed.## A value of 0 means to never release the backlog.## 在某些时候，master 不再连接 slaves，backlog 将被释放。# 如果设置为 0 ，意味着绝不释放 backlog 。# repl-backlog-ttl 3600
# The slave priority is an integer number published by Redis in the INFO output.# It is used by Redis Sentinel in order to select a slave to promote into a# master if the master is no longer working correctly.## A slave with a low priority number is considered better for promotion, so# for instance if there are three slaves 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 slave as not able to perform the# role of master, so a slave with priority of 0 will never be selected by# Redis Sentinel for promotion.## By default the priority is 100.# 指定slave的优先级。在不只1个slave存在的部署环境下，当master宕机时，Redis# Sentinel会将priority值最小的slave提升为master。# 这个值越小，就越会被优先选中，需要注意的是，# 若该配置项为0，则对应的slave永远不会自动提升为master。slave-priority 100
# It is possible for a master to stop accepting writes if there are less than# N slaves connected, having a lag less or equal than M seconds.## The N slaves 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 slave, 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 slaves# are available, to the specified number of seconds## For example to require at least 3 slaves with a lag <= 10 seconds use:## min-slaves-to-write 3# min-slaves-max-lag 10## Setting one or the other to 0 disables the feature.## By default min-slaves-to-write is set to 0 (feature disabled) and# min-slaves-max-lag is set to 10.
################################## SECURITY ##################################################################### 安全 ###################################
# Require clients to issue AUTH <PASSWORD> before processing any other# commands. This might be useful in environments in which you do not trust# others with access to the host running redis-server.## This should stay commented out for backward compatibility and because most# people do not need auth (e.g. they run their own servers).## Warning: since Redis is pretty fast an outside user can try up to# 150k passwords per second against a good box. This means that you should# use a very strong password otherwise it will be very easy to break.## 设置连接redis的密码# redis速度相当快，一个外部用户在一秒钟进行150K次密码尝试，需指定强大的密码来防止暴力破解requirepass set_enough_strong_passwd
# Command renaming.## 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 slaves may cause problems.# 重命名一些高危命令，用来禁止高危命令rename-command FLUSHALL ZYzv6FOBdwflW2nXrename-command CONFIG aI7zwm1GDzMMrEirename-command EVAL S9UHPKEpSvUJMMrename-command FLUSHDB D60FPVDJuip7gy6l
################################### LIMITS ####################################################################### 限制 ####################################
# 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'.## 限制同时连接的客户数量,默认是10000# 当连接数超过这个值时，redis 将不再接收其他连接请求，客户端尝试连接时将收到 error 信息# maxclients 10000
# Don't use more memory than 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 cache, or to set# a hard memory limit for an instance (using the 'noeviction' policy).## WARNING: If you have slaves attached to an instance with maxmemory on,# the size of the output buffers needed to feed the slaves 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 slaves 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 slaves attached it is suggested that you set a lower# limit for maxmemory so that there is some free RAM on the system for slave# output buffers (but this is not needed if the policy is 'noeviction').## 设置redis能够使用的最大内存。# 达到最大内存设置后，Redis会先尝试清除已到期或即将到期的Key（设置过expire信息的key）# 在删除时,按照过期时间进行删除，最早将要被过期的key将最先被删除# 如果已到期或即将到期的key删光，仍进行set操作，那么将返回错误# 此时redis将不再接收写请求,只接收get请求。# maxmemory的设置比较适合于把redis当作于类似memcached 的缓存来使用# maxmemory <bytes>
# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory# is reached. You can select among five behaviors:## volatile-lru -> remove the key with an expire set using an LRU algorithm# allkeys-lru -> remove any key according to the LRU algorithm# volatile-random -> remove a random key with 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 expire at all, just return an error on write operations## 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 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 a bit more CPU. 3 is very fast but not very accurate.## maxmemory-samples 5
############################## 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.
# redis 默认每次更新操作后会在后台异步的把数据库镜像备份到磁盘，但该备份非常耗时，且备份不宜太频繁# redis 同步数据文件是按上面save条件来同步的# 如果发生诸如拉闸限电、拔插头等状况,那么将造成比较大范围的数据丢失# 所以redis提供了另外一种更加高效的数据库备份及灾难恢复方式# 开启append only 模式后,redis 将每一次写操作请求都追加到appendonly.aof 文件中# redis重新启动时,会从该文件恢复出之前的状态。# 但可能会造成 appendonly.aof 文件过大，所以redis支持BGREWRITEAOF 指令，对appendonly.aof重新整理,默认是不开启的。
appendonly no
# The name of the append only file (default: "appendonly.aof")# 默认为appendonly.aof。appendfilename "appendonly.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".
# 设置对 appendonly.aof 文件进行同步的频率,有三种选择always、everysec、no，默认是everysec表示每秒同步一次。# always 表示每次有写操作都进行同步,everysec 表示对写操作进行累积,每秒同步一次。# no表示等操作系统进行数据缓存同步到磁盘，都进行同步,everysec 表示对写操作进行累积,每秒同步一次# 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.# 指定是否在后台aof文件rewrite期间调用fsync，默认为no，表示要调用fsync（无论后台是否有子进程在刷盘）。Redis在后台写RDB文件或重写afo文件期间会存在大量磁盘IO，此时，在某些linux系统中，调用fsync可能会阻塞。no-appendfsync-on-rewrite yes
# 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.# 指定Redis重写aof文件的条件，默认为100，表示与上次rewrite的aof文件大小相比，当前aof文件增长量超过上次afo文件大小的100%时，就会触发background rewrite。若配置为0，则会禁用自动rewriteauto-aof-rewrite-percentage 100
# 指定触发rewrite的aof文件大小。若aof文件小于该值，即使当前文件的增量比例达到auto-aof-rewrite-percentage的配置值，也不会触发自动rewrite。即这两个配置项同时满足时，才会触发rewrite。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
################################ 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.# 一个Lua脚本最长的执行时间，单位为毫秒，如果为0或负数表示无限执行时间，默认为5000lua-time-limit 5000
################################ REDIS CLUSTER ################################# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++# WARNING EXPERIMENTAL: Redis Cluster is considered to be stable code, however# in order to mark it as "mature" we need to wait for a non trivial percentage# of users to deploy it in production.# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++## 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-6379.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 15000
# A slave of a failing master will avoid to start a failover if its data# looks too old.## There is no simple way for a slave to actually have a exact measure of# its "data age", so the following two checks are performed:## 1) If there are multiple slaves able to failover, they exchange messages# in order to try to give an advantage to the slave with the best# replication offset (more data from the master processed).# Slaves 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 slave 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 slave will not try to failover# at all.## The point "2" can be tuned by user. Specifically a slave will not perform# the failover if, since the last interaction with the master, the time# elapsed is greater than:## (node-timeout * slave-validity-factor) + repl-ping-slave-period## So for example if node-timeout is 30 seconds, and the slave-validity-factor# is 10, and assuming a default repl-ping-slave-period of 10 seconds, the# slave will not try to failover if it was not able to talk with the master# for longer than 310 seconds.## A large slave-validity-factor may allow slaves with too old data to failover# a master, while a too small value may prevent the cluster from being able to# elect a slave at all.## For maximum availability, it is possible to set the slave-validity-factor# to a value of 0, which means, that slaves 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-slave-validity-factor 10
# Cluster slaves are able to migrate to orphaned masters, that are masters# that are left without working slaves. 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 slaves.## Slaves migrate to orphaned masters only if there are still at least a# given number of other working slaves for their old master. This number# is the "migration barrier". A migration barrier of 1 means that a slave# will migrate only if there is at least 1 other working slave for its master# and so forth. It usually reflects the number of slaves you want for every# master in your cluster.## Default is 1 (slaves migrate only if their masters remain with at least# one slave). 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
# In order to setup your cluster make sure to read the documentation# available at http://redis.io web site.
################################## 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)# A Alias for g$lshzxe, so that the "AKE" string means all the events.## 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 ""
############################### 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.# 当hash中包含超过指定元素个数并且最大的元素没有超过临界时，# hash将以一种特殊的编码方式（大大减少内存使用）来存储，这里可以设置这两个临界值hash-max-ziplist-entries 512hash-max-ziplist-value 64
# Similarly to hashes, small lists are also encoded in a special way in order# to save a lot of space. The special representation is only used when# you are under the following limits:# list数据类型多少节点以下会采用去指针的紧凑存储格式。# list数据类型节点值大小小于多少字节会采用紧凑存储格式。list-max-ziplist-entries 512list-max-ziplist-value 64
# 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数据类型内部数据如果全部是数值型，且包含多少节点以下会采用紧凑格式存储。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:
# zsort数据类型多少节点以下会采用去指针的紧凑存储格式。# zsort数据类型节点值大小小于多少字节会采用紧凑存储格式。zset-max-ziplist-entries 128zset-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
# 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.
# Redis将在每100毫秒时使用1毫秒的CPU时间来对redis的hash表进行重新hash，可以降低内存的使用# 当你的使用场景中，有非常严格的实时性需要，不能够接受Redis时不时的对请求有2毫秒的延迟的话，把这项配置为no。# 如果没有这么严格的实时性要求，可以设置为yes，以便能够尽可能快的释放内存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# slave -> slave 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 slave clients, since# subscribers and slaves 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 0client-output-buffer-limit slave 256mb 64mb 60client-output-buffer-limit pubsub 32mb 8mb 60
# 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
# 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过程中,是否采取增量文件同步策略,默认为“yes”。 rewrite过程中,每32M数据进行一次文件同步,这样可以减少aof大文件写入对磁盘的操作次数aof-rewrite-incremental-fsync yes
# redis数据存储redis的存储分为内存存储、磁盘存储和log文件三部分，配置文件中有三个参数对其进行配置。save seconds updates，save配置，指出在多长时间内，有多少次更新操作，就将数据同步到数据文件。可多个条件配合，默认配置了三个条件。appendonly yes/no ，appendonly配置，指出是否在每次更新操作后进行日志记录，如果不开启，可能会在断电时导致一段时间内的数据丢失。因为redis本身同步数据文件是按上面的save条件来同步的，所以有的数据会在一段时间内只存在于内存中。appendfsync no/always/everysec ，appendfsync配置，no表示等操作系统进行数据缓存同步到磁盘，always表示每次更新操作后手动调用fsync()将数据写到磁盘，everysec表示每秒同步一次。