一、redis介绍
1)redis简介
redis是一个key-value存储系统。 和Memcached类似,它支持存储的value类型相对更多,包括string(字符串)、list(链表)、set(集合)、zset(sorted set --有序集合)和hash(哈希类型)。 这些数据类型都支持push/pop、add/remove及取交集并集和差集及更丰富的操作,而且这些操作都是原子性的。在此基础上,redis支持各种不同方式的排序。 与memcached一样,为了保证效率,数据都是缓存在内存中。区别的是redis会周期性的把更新的数据写入磁盘或者把修改操作写入追加的记录文件,并且在此基础上实现了master-slave(主从)同步
2)redis的特性,优点
1. 使用Redis有哪些好处? (1) 速度快,因为数据存在内存中,类似于HashMap,HashMap的优势就是查找和操作的时间复杂度都是O(1) (2) 支持丰富数据类型,支持string,list,set,sorted set,hash (3) 支持事务,操作都是原子性,所谓的原子性就是对数据的更改要么全部执行,要么全部不执行 (4) 丰富的特性:可用于缓存,消息,按key设置过期时间,过期后将会自动删除 2. redis相比memcached有哪些优势? (1) memcached所有的值均是简单的字符串,redis作为其替代者,支持更为丰富的数据类型 (2) redis的速度比memcached快很多 (3) redis可以持久化其数据 3. redis常见性能问题和解决方案: (1) Master最好不要做任何持久化工作,如RDB内存快照和AOF日志文件 (2) 如果数据比较重要,某个Slave开启AOF备份数据,策略设置为每秒同步一次 (3) 为了主从复制的速度和连接的稳定性,Master和Slave最好在同一个局域网内 (4) 尽量避免在压力很大的主库上增加从库 (5) 主从复制不要用图状结构,用单向链表结构更为稳定,即:Master <- Slave1 <- Slave2 <- Slave3... 这样的结构方便解决单点故障问题,实现Slave对Master的替换。如果Master挂了,可以立刻启用Slave1做Master,其他不变。 4. MySQL里有2000w数据,redis中只存20w的数据,如何保证redis中的数据都是热点数据 相关知识:redis 内存数据集大小上升到一定大小的时候,就会施行数据淘汰策略。redis 提供 6种数据淘汰策略: voltile-lru:从已设置过期时间的数据集(server.db[i].expires)中挑选最近最少使用的数据淘汰 volatile-ttl:从已设置过期时间的数据集(server.db[i].expires)中挑选将要过期的数据淘汰 volatile-random:从已设置过期时间的数据集(server.db[i].expires)中任意选择数据淘汰 allkeys-lru:从数据集(server.db[i].dict)中挑选最近最少使用的数据淘汰 allkeys-random:从数据集(server.db[i].dict)中任意选择数据淘汰 no-enviction(驱逐):禁止驱逐数据 5. Memcache与Redis的区别都有哪些? 1)、存储方式 Memecache把数据全部存在内存之中,断电后会挂掉,数据不能超过内存大小。 Redis有部份存在硬盘上,这样能保证数据的持久性。 2)、数据支持类型 Memcache对数据类型支持相对简单。 Redis有复杂的数据类型。 3)value大小 redis最大可以达到1GB,而memcache只有1MB 6. Redis 常见的性能问题都有哪些?如何解决? 1).Master写内存快照,save命令调度rdbSave函数,会阻塞主线程的工作,当快照比较大时对性能影响是非常大的,会间断性暂停服务,所以Master最好不要写内存快照。 2).Master AOF持久化,如果不重写AOF文件,这个持久化方式对性能的影响是最小的,但是AOF文件会不断增大,AOF文件过大会影响Master重启的恢复速度。 Master最好不要做任何持久化工作,包括内存快照和AOF日志文件,特别是不要启用内存快照做持久化,如果数据比较关键,某个Slave开启AOF备份数据,策略为每秒同步一次。 3).Master调用BGREWRITEAOF重写AOF文件,AOF在重写的时候会占大量的CPU和内存资源,导致服务load过高,出现短暂服务暂停现象。 4). Redis主从复制的性能问题,为了主从复制的速度和连接的稳定性,Slave和Master最好在同一个局域网内 7, redis 最适合的场景 Redis最适合所有数据in-momory的场景,虽然Redis也提供持久化功能,但实际更多的是一个disk-backed的功能, 跟传统意义上的持久化有比较大的差别,那么可能大家就会有疑问,似乎Redis更像一个加强版的Memcached,那么何时使用Memcached,何时使用Redis呢? 如果简单地比较Redis与Memcached的区别,大多数都会得到以下观点: 1 、Redis不仅仅支持简单的k/v类型的数据,同时还提供list,set,zset,hash等数据结构的存储。 2 、Redis支持数据的备份,即master-slave模式的数据备份。 3 、Redis支持数据的持久化,可以将内存中的数据保持在磁盘中,重启的时候可以再次加载进行使用。 (1)、会话缓存(Session Cache) 最常用的一种使用Redis的情景是会话缓存(session cache)。用Redis缓存会话比其他存储(如Memcached)的优势在于:Redis提供持久化。 (2)全页缓存(FPC) 除基本的会话token之外,Redis还提供很简便的FPC平台。回到一致性问题,即使重启了Redis实例,因为有磁盘的持久化,用户也不会看到页面加载速度的下降,这是一个极大改进,类似PHP本地FPC。 (3)队列 Reids在内存存储引擎领域的一大优点是提供 list 和 set 操作,这使得Redis能作为一个很好的消息队列平台来使用。 Redis作为队列使用的操作,就类似于本地程序语言(如Python)对 list 的 push/pop 操作。 (4)排行榜/计数器 Redis在内存中对数字进行递增或递减的操作实现的非常好。集合(Set)和有序集合(Sorted Set)也使得我们在执行这些操作的时候变的非常简单, Redis只是正好提供了这两种数据结构。所以,我们要从排序集合中获取到排名最靠前的10个用户–我们称之为“user_scores”,我们只需要像下面一样执行即可: (5)发布/订阅 Redis的发布/订阅功能。发布/订阅的使用场景确实非常多。我已看见人们在社交网络连接中使用,还可作为基于发布/订阅的脚本触发器,甚至用Redis的发布/订阅功能来建立聊天系统!
3)redis支持的数据类型(5大数据类型)
redis={ k1:'123', 字符串 k2:[1,2,3,4], 列表/数组 k3:{1,2,3,4} 集合 k4:{name:lqz,age:12} 字典/哈希表 k5:{('lqz',18),('egon',33)} 有序集合 }
最直接的特点
优点:可以持久化
缺点:单线程,单进程
二、redis的安装
1)centos下安装
1.1) 编译安装
wget http://download.redis.io/releases/redis-3.0.6.tar.gz tar xzf redis-3.0.6.tar.gz cd redis-3.0.6 make
1.2)redis的相关命令
redis-benchmark : 用于测试redis的性能。 redis-check-aof : 当aof备份文件被损坏,可通过该工具对aof文件进行修复,使用方式:redis-check-aof --fix 要修复的aof文件。 redis-check-rdb : 修复损坏的rdb备份文件。 redis-cli : redis客户端,用于连接服务端。 redis-server : redis服务器端,用于启动redis服务器。 redis-sentinel : 哨兵模式(实际使用较多) 在master-slave模式下(slave默认不支持写),当master出现异常时,自动在slave中选择一台作为master。
1.3)启动服务端
src/redis-server
1.4)启动客户端测试
src/redis-cli redis> set foo bar OK redis> get foo "bar"
2)windows下安装
2.1)获取安装包。
Windows的Redis安装包需要到以下GitHub链接找到。链接:https://github.com/MSOpenTech/redis。打开网站后,找到Release,点击前往下载页面。
2.2)在下载网页中,找到最后发行的版本(此处是3.2.100)。找到Redis-x64-3.2.100.msi和Redis-x64-3.2.100.zip,点击下载。这里说明一下,第一个是msi微软格式的安装包,第二个是压缩包。
3.3)双击刚下载好的msi格式的安装包(Redis-x64-3.2.100.msi)开始安装。
一直默认下一步
3.4)选择“添加Redis目录到环境变量PATH中”,这样方便系统自动识别Redis执行文件在哪里。
3.5)端口号可保持默认的6379,并选择防火墙例外,从而保证外部可以正常访问Redis服务。
3.6)端口号可保持默认的6379,并选择防火墙例外,从而保证外部可以正常访问Redis服务。
3.7)设定最大值为100M。作为实验和学习,100M足够了。
3.8)安装完毕后,需要先做一些设定工作,以便服务启动后能正常运行。使用文本编辑器,这里使用Notepad++,打开Redis服务配置文件。
注意:不要找错了,通常为redis.windows-service.conf,而不是redis.windows.conf。后者是以非系统服务方式启动程序使用的配置文件。 找到含有requirepass字样的地方,追加一行,输入requirepass 12345。这是访问Redis时所需的密码,一般测试情况下可以不用设定密码。 不过,即使是作为本地访问,也建议设定一个密码。此处以简单的12345来演示
3.9)启动服务
点击“开始”>右击“计算机”>选择“管理”。 在左侧栏中依次找到并点击“计算机管理(本地)”>服务和应用程序>服务。 再在右侧找到Redis名称的服务,查看启动情况。如未启动,则手动启动之。正常情况下,服务应该正常启动并运行了。
进行连接测试。进入Redis的目录,cd C:\Program Files\Redis。输入redis-cli并回车。(redis-cli是客户端程序)如图正常提示进入,并显示正确端口号,则表示服务已经启动。
使用服务前需要先通过密码验证。输入“auth 12345”并回车(12345是之前设定的密码)。返回提示OK表示验证通过。
原文链接:https://www.cnblogs.com/liuqingzheng/p/9831331.html
三、redis多进程的配置(含主从同步)
1)配置redis(主)
include /etc/redis/redis_common.conf maxmemory 1048576kb maxmemory-policy noeviction dir "/var/data/redis/redis999" logfile "/var/log/redis/redis999.log" port 5999 pidfile "/var/run/redis/redis999.pid" # Generated by CONFIG REWRITE daemonize yes save 1800 1 stop-writes-on-bgsave-error no rdbcompression no repl-ping-slave-period 1 repl-timeout 10 repl-backlog-size 64mb repl-disable-tcp-nodelay yes activerehashing no client-output-buffer-limit normal 0 0 0 client-output-buffer-limit slave 512mb 128mb 120
其中包含了,redis_common.conf
该文件包含了注释
# Redis configuration file example # Note on units: when memory size is needed, it is possible to specify # it in the usual form of 1k 5GB 4M and so forth: # # 1k => 1000 bytes # 1kb => 1024 bytes # 1m => 1000000 bytes # 1mb => 1024*1024 bytes # 1g => 1000000000 bytes # 1gb => 1024*1024*1024 bytes # # units are case insensitive so 1GB 1Gb 1gB are all the same. # By default Redis does not run as a daemon. Use 'yes' if you need it. # Note that Redis will write a pid file in /var/run/redis.pid when daemonized. daemonize yes # When running daemonized, Redis writes a pid file in /var/run/redis.pid by # default. You can specify a custom pid file location here. # 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. # port 6379 # 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 # bind 127.0.0.1 # 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 755 # Close the connection after a client is idle for N seconds (0 to disable) timeout 0 # TCP keepalive. # # If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence # of communication. This is useful for two reasons: # # 1) Detect dead peers. # 2) Take the connection alive from the point of view of network # equipment in the middle. # # On Linux, the specified value (in seconds) is the period used to send ACKs. # Note that to close the connection the double of the time is needed. # On other kernels the period depends on the kernel configuration. # # A reasonable value for this option is 60 seconds. 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) loglevel notice # Specify the log file name. Also the emptry string can be used to force # Redis to log on the standard output. Note that if you use standard # output for logging but daemonize, logs will be sent to /dev/null # logfile "" # To enable logging to the system logger, just set 'syslog-enabled' to yes, # and optionally update the other syslog parameters to suit your needs. # syslog-enabled no # Specify the syslog identity. # syslog-ident redis # Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7. # syslog-facility local0 # Set the number of databases. The default database is DB 0, you can select # a different one on a per-connection basis using SELECT <dbid> where # dbid is a number between 0 and 'databases'-1 databases 16 ################################ SNAPSHOTTING ################################# # # Save the DB on disk: # # save <seconds> <changes> # # Will save the DB if both the given number of seconds and the given # number of write operations against the DB occurred. # # In the example below the behaviour will be to save: # after 900 sec (15 min) if at least 1 key changed # after 300 sec (5 min) if at least 10 keys changed # after 60 sec if at least 10000 keys changed # # Note: you can disable saving at all commenting all the "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 "" # Saving is handled by archivedaemon save 1800 1 #save 900 1 #save 600 10 #save 300 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 an hard way) that data is not persisting # on disk properly, otherwise chances are that no one will notice and some # distater 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 usually even if there are problems with disk, # permissions, and so forth. stop-writes-on-bgsave-error no # Compress string objects using LZF when dump .rdb databases? # For default that's set to 'yes' as it's almost always a win. # If you want to save some CPU in the saving child set it to 'no' but # the dataset will likely be bigger if you have compressible values or keys. rdbcompression no # Since version 5 of RDB a CRC64 checksum is placed at the end of the file. # This makes the format more resistant to corruption but there is a performance # hit to pay (around 10%) when saving and loading RDB files, so you can disable it # for maximum performances. # # RDB files created with checksum disabled have a checksum of zero that will # tell the loading code to skip the check. rdbchecksum yes # The filename where to dump the DB dbfilename dump.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. #dir "/data/redis3" ################################# REPLICATION ################################# # Master-Slave replication. Use slaveof to make a Redis instance a copy of # another Redis server. Note that the configuration is local to the slave # so for example it is possible to configure the slave to save the DB with a # different interval, or to listen to another port, and so on. # # 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. # # 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. # 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 extend you can improve # security of read only slaves using 'rename-command' to shadow all the # administrative / dangerous commands. slave-read-only yes # 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. # repl-ping-slave-period 1 # 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. # repl-timeout 10 # 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. repl-disable-tcp-nodelay yes # 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 biggest 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. repl-backlog-size 64mb # 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. # # 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 wtih 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. 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 GUARANTEES 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 ################################### # 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. # # requirepass foobared # 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. ################################### LIMITS #################################### # Set the max number of connected clients at the same time. By default # this limit is set to 10000 clients, however if the Redis server is not # able to configure the process file limit to allow for the specified limit # the max number of allowed clients is set to the current file limit # minus 32 (as Redis reserves a few file descriptors for internal uses). # # Once the limit is reached Redis will close all the new connections sending # an error 'max number of clients reached'. # # maxclients 10000 # Don't use more memory than the specified amount of bytes. # When the memory limit is reached Redis will try to remove keys # accordingly to the eviction policy selected (see maxmemmory-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 # an 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'). # # 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 accordingly 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 not suitable keys for eviction. # # At the date of writing this 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 volatile-lru # LRU and minimal TTL algorithms are not precise algorithms but approximated # algorithms (in order to save memory), so you can select as well the sample # size to check. For instance for default Redis will check three keys and # pick the one that was used less recently, you can change the sample size # using the following configuration directive. # # maxmemory-samples 3 ############################## APPEND ONLY MODE ############################### # By default Redis asynchronously dumps the dataset on disk. This mode is # good enough in many applications, but an issue with the Redis process or # a power outage may result into a few minutes of writes lost (depending on # the configured save points). # # The Append Only File is an alternative persistence mode that provides # much better durability. For instance using the default data fsync policy # (see later in the config file) Redis can lose just one second of writes in a # dramatic event like a server power outage, or a single write if something # wrong with the Redis process itself happens, but the operating system is # still running correctly. # # AOF and RDB persistence can be enabled at the same time without problems. # If the AOF is enabled on startup Redis will load the AOF, that is the file # with the better durability guarantees. # # Please check http://redis.io/topics/persistence for more information. appendonly no # The name of the append only file (default: "appendonly.aof") # appendfilename appendonly.aof # The fsync() call tells the Operating System to actually write data on disk # instead to wait for more data in the output buffer. Some OS will really flush # data on disk, some other OS will just try to do it ASAP. # # Redis supports three different modes: # # no: don't fsync, just let the OS flush the data when it wants. Faster. # always: fsync after every write to the append only log . Slow, Safest. # everysec: fsync only one time every second. Compromise. # # The default is "everysec", as that's usually the right compromise between # speed and data safety. It's up to you to understand if you can relax this to # "no" that will let the operating system flush the output buffer when # it wants, for better performances (but if you can live with the idea of # some data loss consider the default persistence mode that's snapshotting), # or on the contrary, use "always" that's very slow but a bit safer than # everysec. # # More details please check the following article: # http://antirez.com/post/redis-persistence-demystified.html # # If unsure, use "everysec". # appendfsync always appendfsync everysec # appendfsync no # When the AOF fsync policy is set to always or everysec, and a background # saving process (a background save or AOF log background rewriting) is # performing a lot of I/O against the disk, in some Linux configurations # Redis may block too long on the fsync() call. Note that there is no fix for # this currently, as even performing fsync in a different thread will block # our synchronous write(2) call. # # In order to mitigate this problem it's possible to use the following option # that will prevent fsync() from being called in the main process while a # BGSAVE or BGREWRITEAOF is in progress. # # This means that while another child is saving, the durability of Redis is # the same as "appendfsync none". In practical terms, this means that it is # possible to lose up to 30 seconds of log in the worst scenario (with the # default Linux settings). # # If you have latency problems turn this to "yes". Otherwise leave it as # "no" that is the safest pick from the point of view of durability. no-appendfsync-on-rewrite no # Automatic rewrite of the append only file. # Redis is able to automatically rewrite the log file implicitly calling # BGREWRITEAOF when the AOF log size grows by the specified percentage. # # This is how it works: Redis remembers the size of the AOF file after the # latest rewrite (if no rewrite has happened since the restart, the size of # the AOF at startup is used). # # This base size is compared to the current size. If the current size is # bigger than the specified percentage, the rewrite is triggered. Also # you need to specify a minimal size for the AOF file to be rewritten, this # is useful to avoid rewriting the AOF file even if the percentage increase # is reached but it is still pretty small. # # Specify a percentage of zero in order to disable the automatic AOF # rewrite feature. auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb ################################ 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 exceed 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 commands was # already issue by the script but the user don't want to wait for the natural # termination of the script. # # Set it to 0 or a negative value for unlimited execution without warnings. lua-time-limit 5000 ################################## 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 ############################# Event notification ############################## # Redis can notify Pub/Sub clients about events happening in the key space. # This feature is documented at http://redis.io/topics/keyspace-events # # 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 # by zero or multiple characters. The empty string means that notifications # are disabled at all. # # 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. hash-max-ziplist-entries 512 hash-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-max-ziplist-entries 512 list-max-ziplist-value 64 # Sets have a special encoding in just one case: when a set is composed # of just strings that happens to be integers in radix 10 in the range # of 64 bit signed integers. # The following configuration setting sets the limit in the size of the # set in order to use this special memory saving encoding. set-max-intset-entries 512 # Similarly to hashes and lists, sorted sets are also specially encoded in # order to save a lot of space. This encoding is only used when the length and # elements of a sorted set are below the following limits: zset-max-ziplist-entries 128 zset-max-ziplist-value 64 # 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 an 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 # active rehashing 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 form time to time # to queries with 2 milliseconds delay. # # use "activerehashing yes" if you don't have such hard requirements but # want to free memory asap when possible. activerehashing no # 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 # slave -> slave clients and MONITOR clients # pubsub -> clients subcribed 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 0 client-output-buffer-limit slave 512mb 128mb 120 client-output-buffer-limit pubsub 32mb 8mb 60 # Redis calls an internal function to perform many background tasks, like # closing connections of clients in timeot, 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 accordingly 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-incremental-fsync yes ################################## INCLUDES ################################### # Include one or more other config files here. This is useful if you # have a standard template that goes to all Redis server but also need # to customize a few per-server settings. Include files can include # other files, so use this wisely. # # include /path/to/local.conf # include /path/to/other.conf
过滤注释文件
[root@mlcs redis]# egrep -v "^#|^$" redis_common.conf daemonize yes timeout 0 tcp-keepalive 0 loglevel notice databases 16 save 1800 1 stop-writes-on-bgsave-error no rdbcompression no rdbchecksum yes dbfilename dump.rdb slave-serve-stale-data yes slave-read-only yes repl-ping-slave-period 1 repl-timeout 10 repl-disable-tcp-nodelay yes repl-backlog-size 64mb slave-priority 100 appendonly no appendfsync everysec no-appendfsync-on-rewrite no auto-aof-rewrite-percentage 100 auto-aof-rewrite-min-size 64mb lua-time-limit 5000 slowlog-log-slower-than 10000 slowlog-max-len 128 notify-keyspace-events "" hash-max-ziplist-entries 512 hash-max-ziplist-value 64 list-max-ziplist-entries 512 list-max-ziplist-value 64 set-max-intset-entries 512 zset-max-ziplist-entries 128 zset-max-ziplist-value 64 activerehashing no client-output-buffer-limit normal 0 0 0 client-output-buffer-limit slave 512mb 128mb 120 client-output-buffer-limit pubsub 32mb 8mb 60 hz 10 aof-rewrite-incremental-fsync yes
启动(配置文件中的文件路径需要创建出来)
/usr/local/redis/bin/redis-server /usr/local/redis/etc/redis_5999.conf &
2)redis从,配置
[root@mlcs redis]# more redis_6999.conf include /etc/redis/redis_common.conf maxmemory 1048576kb maxmemory-policy noeviction dir "/var/data/redis-slave/redis999" logfile "/var/log/redis/redis-slave999.log" port 6999 pidfile "/var/run/redis/redis-slave999.pid" # Generated by CONFIG REWRITE daemonize yes save 1800 1 stop-writes-on-bgsave-error no rdbcompression no repl-ping-slave-period 1 repl-timeout 10 repl-backlog-size 64mb repl-disable-tcp-nodelay yes activerehashing no client-output-buffer-limit normal 0 0 0 client-output-buffer-limit slave 512mb 128mb 120 slaveof 127.0.0.1 5999