1. Redis默认不是以守护进程的方式运行,可以通过该配置项修改,使用yes启用守护进程 daemonize no 2. 当Redis以守护进程方式运行时,Redis默认会把pid写入/var/run/redis.pid文件,可以通过pidfile指定 pidfile /var/run/redis.pid 3. 指定Redis监听端口,默认端口为6379,作者在自己的一篇博文中解释了为什么选用6379作为默认端口,因为6379在手机按键上MERZ对应的号码,而MERZ取自意大利歌女Alessia Merz的名字 port 6379 4. 绑定的主机地址 bind 127.0.0.1 5.当 客户端闲置多长时间后关闭连接,如果指定为0,表示关闭该功能 timeout 300 6. 指定日志记录级别,Redis总共支持四个级别:debug、verbose、notice、warning,默认为verbose loglevel verbose 7. 日志记录方式,默认为标准输出,如果配置Redis为守护进程方式运行,而这里又配置为日志记录方式为标准输出,则日志将会发送给/dev/null logfile stdout 8. 设置数据库的数量,默认数据库为0,可以使用SELECT <dbid>命令在连接上指定数据库id databases 16 9. 指定在多长时间内,有多少次更新操作,就将数据同步到数据文件,可以多个条件配合 save <seconds> <changes> Redis默认配置文件中提供了三个条件: save 900 1 save 300 10 save 60 10000 分别表示900秒(15分钟)内有1个更改,300秒(5分钟)内有10个更改以及60秒内有10000个更改。
10. 指定存储至本地数据库时是否压缩数据,默认为yes,Redis采用LZF压缩,如果为了节省CPU时间,可以关闭该选项,但会导致数据库文件变的巨大 rdbcompression yes 11. 指定本地数据库文件名,默认值为dump.rdb dbfilename dump.rdb 12. 指定本地数据库存放目录 dir ./ 13. 设置当本机为slav服务时,设置master服务的IP地址及端口,在Redis启动时,它会自动从master进行数据同步 slaveof <masterip> <masterport> 14. 当master服务设置了密码保护时,slav服务连接master的密码 masterauth <master-password> 15. 设置Redis连接密码,如果配置了连接密码,客户端在连接Redis时需要通过AUTH <password>命令提供密码,默认关闭 requirepass foobared 16. 设置同一时间最大客户端连接数,默认无限制,Redis可以同时打开的客户端连接数为Redis进程可以打开的最大文件描述符数,如果设置 maxclients 0,表示不作限制。当客户端连接数到达限制时,Redis会关闭新的连接并向客户端返回max number of clients reached错误信息 maxclients 128 17. 指定Redis最大内存限制,Redis在启动时会把数据加载到内存中,达到最大内存后,Redis会先尝试清除已到期或即将到期的Key,当此方法处理 后,仍然到达最大内存设置,将无法再进行写入操作,但仍然可以进行读取操作。Redis新的vm机制,会把Key存放内存,Value会存放在swap区 maxmemory <bytes> 18. 指定是否在每次更新操作后进行日志记录,Redis在默认情况下是异步的把数据写入磁盘,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。默认为no appendonly no 19. 指定更新日志文件名,默认为appendonly.aof appendfilename appendonly.aof
20. 指定更新日志条件,共有3个可选值: appendfsync everysec
21. 指定是否启用虚拟内存机制,默认值为no,简单的介绍一下,VM机制将数据分页存放,由Redis将访问量较少的页即冷数据swap到磁盘上,访问多的页面由磁盘自动换出到内存中(在后面的文章我会仔细分析Redis的VM机制) vm-enabled no 22. 虚拟内存文件路径,默认值为/tmp/redis.swap,不可多个Redis实例共享 vm-swap-file /tmp/redis.swap 23. 将所有大于vm-max-memory的数据存入虚拟内存,无论vm-max-memory设置多小,所有索引数据都是内存存储的(Redis的索引数据 就是keys),也就是说,当vm-max-memory设置为0的时候,其实是所有value都存在于磁盘。默认值为0 vm-max-memory 0 24. Redis swap文件分成了很多的page,一个对象可以保存在多个page上面,但一个page上不能被多个对象共享,vm-page-size是要根据存储的 数据大小来设定的,作者建议如果存储很多小对象,page大小最好设置为32或者64bytes;如果存储很大大对象,则可以使用更大的page,如果不 确定,就使用默认值 vm-page-size 32 25. 设置swap文件中的page数量,由于页表(一种表示页面空闲或使用的bitmap)是在放在内存中的,,在磁盘上每8个pages将消耗1byte的内存。 vm-pages 134217728 26. 设置访问swap文件的线程数,最好不要超过机器的核数,如果设置为0,那么所有对swap文件的操作都是串行的,可能会造成比较长时间的延迟。默认值为4 vm-max-threads 4 27. 设置在向客户端应答时,是否把较小的包合并为一个包发送,默认为开启 glueoutputbuf yes 28. 指定在超过一定的数量或者最大的元素超过某一临界值时,采用一种特殊的哈希算法 hash-max-zipmap-entries 64 hash-max-zipmap-value 512 29. 指定是否激活重置哈希,默认为开启(后面在介绍Redis的哈希算法时具体介绍) activerehashing yes 30. 指定包含其它的配置文件,可以在同一主机上多个Redis实例之间使用同一份配置文件,而同时各个实例又拥有自己的特定配置文件 include /path/to/local.conf
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# Redis configuration file example
# Note on units: when memory size is needed, it is possible to specifiy # 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 /usr/local/redis/run/redis.pid # Accept connections on the specified port, default is 6379 port 6379 # If you want you can bind a single interface, if the bind option is not # specified all the interfaces will listen for incoming connections. # #bind 192.168.20.12 # Close the connection after a client is idle for N seconds (0 to disable) timeout 300 # Set server verbosity to 'debug' # it 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 verbose # Specify the log file name. Also 'stdout' 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 stdout logfile ./logs/redis.log # 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. save 900 1 save 300 10 save 60 10000 # Compress string objects using LZF when dump .rdb databases? # For default that's set to 'yes' as it's almost always a win. # If you want to save some CPU in the saving child set it to 'no' but # the dataset will likely be bigger if you have compressible values or keys. rdbcompression yes # 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. # # Also the Append Only File will be created inside this directory. # # Note that you must specify a directory here, not a file name. dir ./data/ ################################# 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> ################################## 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 ################################### LIMITS #################################### # Set the max number of connected clients at the same time. By default there # is no limit, and it's up to the number of file descriptors the Redis process # is able to open. The special value '0' means no limits. # Once the limit is reached Redis will close all the new connections sending # an error 'max number of clients reached'. # # maxclients 128 # Don't use more memory than the specified amount of bytes. # When the memory limit is reached Redis will try to remove keys with an # EXPIRE set. It will try to start freeing keys that are going to expire # in little time and preserve keys with a longer time to live. # Redis will also try to remove objects from free lists if possible. # # If all this fails, Redis will start to reply with errors to commands # that will use more memory, like SET, LPUSH, and so on, and will continue # to reply to most read-only commands like GET. # # WARNING: maxmemory can be a good idea mainly if you want to use Redis as a # 'state' server or cache, not as a real DB. When Redis is used as a real # database the memory usage will grow over the weeks, it will be obvious if # it is going to use too much memory in the long run, and you'll have the time # to upgrade. With maxmemory after the limit is reached you'll start to get # errors for write operations, and this may even lead to DB inconsistency. # # maxmemory <bytes> ############################## APPEND ONLY MODE ############################### # By default Redis asynchronously dumps the dataset on disk. If you can live # with the idea that the latest records will be lost if something like a crash # happens this is the preferred way to run Redis. If instead you care a lot # about your data and don't want to that a single record can get lost you should # enable the append only mode: when this mode is enabled Redis will append # every write operation received in the file appendonly.aof. This file will # be read on startup in order to rebuild the full dataset in memory. # # Note that you can have both the async dumps and the append only file if you # like (you have to comment the "save" statements above to disable the dumps). # Still if append only mode is enabled Redis will load the data from the # log file at startup ignoring the dump.rdb file. # # IMPORTANT: Check the BGREWRITEAOF to check how to rewrite the append # log file in background when it gets too big. appendonly yes # 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 if one second passed since the last fsync. Compromise. # # The default is "everysec" 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 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. # # If unsure, use "everysec". # appendfsync always appendfsync everysec # appendfsync no ################################ VIRTUAL MEMORY ############################### # Virtual Memory allows Redis to work with datasets bigger than the actual # amount of RAM needed to hold the whole dataset in memory. # In order to do so very used keys are taken in memory while the other keys # are swapped into a swap file, similarly to what operating systems do # with memory pages. # # To enable VM just set 'vm-enabled' to yes, and set the following three # VM parameters accordingly to your needs. vm-enabled no # vm-enabled yes # This is the path of the Redis swap file. As you can guess, swap files # can't be shared by different Redis instances, so make sure to use a swap # file for every redis process you are running. Redis will complain if the # swap file is already in use. # # The best kind of storage for the Redis swap file (that's accessed at random) # is a Solid State Disk (SSD). # # *** WARNING *** if you are using a shared hosting the default of putting # the swap file under /tmp is not secure. Create a dir with access granted # only to Redis user and configure Redis to create the swap file there. vm-swap-file /tmp/redis.swap # vm-max-memory configures the VM to use at max the specified amount of # RAM. Everything that deos not fit will be swapped on disk *if* possible, that # is, if there is still enough contiguous space in the swap file. # # With vm-max-memory 0 the system will swap everything it can. Not a good # default, just specify the max amount of RAM you can in bytes, but it's # better to leave some margin. For instance specify an amount of RAM # that's more or less between 60 and 80% of your free RAM. vm-max-memory 0 # Redis swap files is split into pages. An object can be saved using multiple # contiguous pages, but pages can't be shared between different objects. # So if your page is too big, small objects swapped out on disk will waste # a lot of space. If you page is too small, there is less space in the swap # file (assuming you configured the same number of total swap file pages). # # If you use a lot of small objects, use a page size of 64 or 32 bytes. # If you use a lot of big objects, use a bigger page size. # If unsure, use the default :) vm-page-size 32 # Number of total memory pages in the swap file. # Given that the page table (a bitmap of free/used pages) is taken in memory, # every 8 pages on disk will consume 1 byte of RAM. # # The total swap size is vm-page-size * vm-pages # # With the default of 32-bytes memory pages and 134217728 pages Redis will # use a 4 GB swap file, that will use 16 MB of RAM for the page table. # # It's better to use the smallest acceptable value for your application, # but the default is large in order to work in most conditions. vm-pages 134217728 # Max number of VM I/O threads running at the same time. # This threads are used to read/write data from/to swap file, since they # also encode and decode objects from disk to memory or the reverse, a bigger # number of threads can help with big objects even if they can't help with # I/O itself as the physical device may not be able to couple with many # reads/writes operations at the same time. # # The special value of 0 turn off threaded I/O and enables the blocking # Virtual Memory implementation. vm-max-threads 4 ############################### ADVANCED CONFIG ############################### # Glue small output buffers together in order to send small replies in a # single TCP packet. Uses a bit more CPU but most of the times it is a win # in terms of number of queries per second. Use 'yes' if unsure. glueoutputbuf yes # Hashes are encoded in a special way (much more memory efficient) when they # have at max a given numer of elements, and the biggest element does not # exceed a given threshold. You can configure this limits with the following # configuration directives. hash-max-zipmap-entries 64 hash-max-zipmap-value 512 # 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 rhashing, 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 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 (责任编辑:IT) |