redis.conf 配置文件

# Redis configuration file example

# Note on units: when memory size is needed, it is possible tospecify

# 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 thesame.

# By default Redis does not run as a daemon. Use 'yes' if youneed it.

# Note that Redis will write a pid file in /var/run/redis.pidwhen daemonized.

daemonize no

# When running daemonized, Redis writes a pid file in/var/run/redis.pid by

# default. You can specify a custom pid file locationhere.

pidfile /var/run/redis.pid

# Accept connections on the specified port, default is6379.

# If port 0 is specified Redis will not listen on a TCPsocket.

port 6379

# If you want you can bind a single interface, if the bindoption is not

# specified all the interfaces will listen for incomingconnections.

#

# bind 127.0.0.1

# Specify the path for the unix socket that will be used tolisten for

# incoming connections. There is no default, so Redis will notlisten

# on a unix socket when not specified.

#

# unixsocket /tmp/redis.sock

# unixsocketperm 755

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

timeout 0

# TCP keepalive.

#

# If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients inabsence

# of communication. This is useful for two reasons:

#

# 1) Detect dead peers.

# 2) Take the connection alive from the point of view ofnetwork

#    equipment in themiddle.

#

# On Linux, the specified value (in seconds) is the periodused to send ACKs.

# Note that to close the connection the double of the time isneeded.

# On other kernels the period depends on the kernelconfiguration.

#

# 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 fordevelopment/testing)

# verbose (many rarely useful info, but not a mess like thedebug level)

# notice (moderately verbose, what you want in productionprobably)

# warning (only very important / critical messages arelogged)

loglevel notice

# Specify the log file name. Also 'stdout' can be used toforce

# Redis to log on the standard output. Note that if you usestandard

# output for logging but daemonize, logs will be sent to/dev/null

logfile stdout

# To enable logging to the system logger, just set'syslog-enabled' to yes,

# and optionally update the other syslog parameters to suityour needs.

# syslog-enabled no

# Specify the syslog identity.

# syslog-ident redis

# Specify the syslog facility. Must be USER or betweenLOCAL0-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 SELECTwhere

# dbid is a number between 0 and 'databases'-1

databases 16

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

#

# Save the DB on disk:

#

#   save

#

#   Will save the DB if both the given numberof seconds and the given

#   number of write operations against the DBoccurred.

#

#   In the example below the behaviour willbe to save:

#   after 900 sec (15 min) if at least 1 keychanged

#   after 300 sec (5 min) if at least 10 keyschanged

#   after 60 sec if at least 10000 keyschanged

#

#   Note: you can disable saving at allcommenting all the "save" lines.

#

#   It is also possible to remove all thepreviously configured save

#   points by adding a save directive with asingle empty string argument

#   like in the following example:

#

#   save ""

save 900 1

save 300 10

save 60 10000

# By default Redis will stop accepting writes if RDB snapshotsare enabled

# (at least one save point) and the latest background savefailed.

# This will make the user aware (in an hard way) that data isnot persisting

# on disk properly, otherwise chances are that no one willnotice and some

# distater will happen.

#

# If the background saving process will start working againRedis will

# automatically allow writes again.

#

# However if you have setup your proper monitoring of theRedis server

# and persistence, you may want to disable this feature sothat Redis will

# continue to work as usually even if there are problems withdisk,

# permissions, and so forth.

stop-writes-on-bgsave-error yes

# Compress string objects using LZF when dump .rdbdatabases?

# For default that's set to 'yes' as it's almost always awin.

# 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 compressiblevalues or keys.

rdbcompression yes

# Since version 5 of RDB a CRC64 checksum is placed at the endof the file.

# This makes the format more resistant to corruption but thereis 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 ofzero 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 thefilename specified

# above using the 'dbfilename' configuration directive.

# 

# The Append Only File will also be created inside thisdirectory.

# 

# Note that you must specify a directory here, not a filename.

dir ./

################################# REPLICATION#################################

# Master-Slave replication. Use slaveof to make a Redisinstance a copy of

# another Redis server. Note that the configuration is localto the slave

# so for example it is possible to configure the slave to savethe DB with a

# different interval, or to listen to another port, and soon.

#

# slaveof

# If the master is password protected (using the "requirepass"configuration

# directive below) it is possible to tell the slave toauthenticate before

# starting the replication synchronization process, otherwisethe master will

# refuse the slave request.

#

# masterauth

# When a slave loses its connection with the master, or whenthe replication

# is still in progress, the slave can act in two differentways:

#

# 1) if slave-serve-stale-data is set to 'yes' (the default)the slave will

#    still reply to clientrequests, possibly with out of date data, or the

#    data set may just beempty if this is the first synchronization.

#

# 2) if slave-serve-stale-data is set to 'no' the slave willreply with

#    an error "SYNC withmaster in progress" to all the kind of commands

#    but to INFO andSLAVEOF.

#

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 withthe master) but

# may also cause problems if clients are writing to it becauseof a

# misconfiguration.

#

# Since Redis 2.6 by default slaves are read-only.

#

# Note: read only slaves are not designed to be exposed tountrusted clients

# on the internet. It's just a protection layer against misuseof the instance.

# Still a read only slave exports by default all theadministrative commands

# such as CONFIG, DEBUG, and so forth. To a limited extend youcan improve

# security of read only slaves using 'rename-command' toshadow all the

# administrative / dangerous commands.

slave-read-only yes

# Slaves send PINGs to server in a predefined interval. It'spossible to change

# this interval with the repl_ping_slave_period option. Thedefault value is 10

# seconds.

#

# repl-ping-slave-period 10

# The following option sets a timeout for both Bulk transferI/O timeout and

# master data or ping response timeout. The default value is60 seconds.

#

# It is important to make sure that this value is greater thanthe value

# specified for repl-ping-slave-period otherwise a timeoutwill be detected

# every time there is low traffic between the master and theslave.

#

# repl-timeout 60

# Disable TCP_NODELAY on the slave socket after SYNC?

#

# If you select "yes" Redis will use a smaller number of TCPpackets and

# less bandwidth to send data to slaves. But this can add adelay for

# the data to appear on the slave side, up to 40 millisecondswith

# Linux kernels using a default configuration.

#

# If you select "no" the delay for data to appear on the slaveside will

# be reduced but more bandwidth will be used forreplication.

#

# By default we optimize for low latency, but in very hightraffic conditions

# or when the master and slaves are many hops away, turningthis to "yes" may

# be a good idea.

repl-disable-tcp-nodelay no

# The slave priority is an integer number published by Redisin the INFO output.

# It is used by Redis Sentinel in order to select a slave topromote into a

# master if the master is no longer working correctly.

#

# A slave with a low priority number is considered better forpromotion, 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 ableto perform the

# role of master, so a slave with priority of 0 will never beselected by

# Redis Sentinel for promotion.

#

# By default the priority is 100.

slave-priority 100

################################## SECURITY###################################

# Require clients to issue AUTH before processing anyother

# commands.  This might be useful inenvironments in which you do not trust

# others with access to the host running redis-server.

#

# This should stay commented out for backward compatibilityand because most

# people do not need auth (e.g. they run their ownservers).

# 

# Warning: since Redis is pretty fast an outside user can tryup to

# 150k passwords per second against a good box. This meansthat you should

# use a very strong password otherwise it will be very easy tobreak.

#

# requirepass foobared

# Command renaming.

#

# It is possible to change the name of dangerous commands in ashared

# environment. For instance the CONFIG command may be renamedinto something

# hard to guess so that it will still be available forinternal-use tools

# but not available for general clients.

#

# Example:

#

# rename-command CONFIGb840fc02d524045429941cc15f59e41cb7be6c52

#

# It is also possible to completely kill a command by renamingit into

# an empty string:

#

# rename-command CONFIG ""

#

# Please note that changing the name of commands that arelogged into the

# AOF file or transmitted to slaves may cause problems.

################################### LIMITS####################################

# Set the max number of connected clients at the same time. Bydefault

# this limit is set to 10000 clients, however if the Redisserver is not

# able to configure the process file limit to allow for thespecified limit

# the max number of allowed clients is set to the current filelimit

# minus 32 (as Redis reserves a few file descriptors forinternal uses).

#

# Once the limit is reached Redis will close all the newconnections sending

# an error 'max number of clients reached'.

#

# maxclients 10000

# Don't use more memory than the specified amount ofbytes.

# When the memory limit is reached Redis will try to removekeys

# accordingly to the eviction policy selected (seemaxmemmory-policy).

#

# If Redis can't remove keys according to the policy, or ifthe policy is

# set to 'noeviction', Redis will start to reply with errorsto commands

# that would use more memory, like SET, LPUSH, and so on, andwill continue

# to reply to read-only commands like GET.

#

# This option is usually useful when using Redis as an LRUcache, or to set

# an hard memory limit for an instance (using the 'noeviction'policy).

#

# WARNING: If you have slaves attached to an instance withmaxmemory on,

# the size of the output buffers needed to feed the slaves aresubtracted

# from the used memory count, so that network problems /resyncs will

# not trigger a loop where keys are evicted, and in turn theoutput

# buffer of slaves is full with DELs of keys evictedtriggering the deletion

# of more keys, and so forth until the database is completelyemptied.

#

# In short... if you have slaves attached it is suggested thatyou set a lower

# limit for maxmemory so that there is some free RAM on thesystem for slave

# output buffers (but this is not needed if the policy is'noeviction').

#

# maxmemory

# MAXMEMORY POLICY: how Redis will select what to remove whenmaxmemory

# is reached. You can select among five behaviors:

# 

# volatile-lru -> remove the key with an expire set usingan LRU algorithm

# allkeys-lru -> remove any key accordingly to the LRUalgorithm

# volatile-random -> remove a random key with an expireset

# allkeys-random -> remove a random key, any key

# volatile-ttl -> remove the key with the nearest expiretime (minor TTL)

# noeviction -> don't expire at all, just return an erroron write operations

# 

# Note: with any of the above policies, Redis will return anerror on write

#      operations, when there are not suitable keys for eviction.

#

#       Atthe date of writing this commands are: set setnx setex append

#      incr decr rpush lpush rpushx lpushx linsert lset rpoplpushsadd

#      sinter sinterstore sunion sunionstore sdiff sdiffstore zaddzincrby

#      zunionstore zinterstore hset hsetnx hmset hincrby incrbydecrby

#      getset mset msetnx exec sort

#

# The default is:

#

# maxmemory-policy volatile-lru

# LRU and minimal TTL algorithms are not precise algorithmsbut approximated

# algorithms (in order to save memory), so you can select aswell the sample

# size to check. For instance for default Redis will checkthree keys and

# pick the one that was used less recently, you can change thesample 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 theRedis 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 thatprovides

# much better durability. For instance using the default datafsync policy

# (see later in the config file) Redis can lose just onesecond of writes in a

# dramatic event like a server power outage, or a single writeif something

# wrong with the Redis process itself happens, but theoperating system is

# still running correctly.

#

# AOF and RDB persistence can be enabled at the same timewithout 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 moreinformation.

appendonly no

# The name of the append only file (default:"appendonly.aof")

# appendfilename appendonly.aof

# The fsync() call tells the Operating System to actuallywrite data on disk

# instead to wait for more data in the output buffer. Some OSwill really flush 

# data on disk, some other OS will just try to do itASAP.

#

# Redis supports three different modes:

#

# no: don't fsync, just let the OS flush the data when itwants. 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 rightcompromise between

# speed and data safety. It's up to you to understand if youcan relax this to

# "no" that will let the operating system flush the outputbuffer when

# it wants, for better performances (but if you can live withthe idea of

# some data loss consider the default persistence mode that'ssnapshotting),

# or on the contrary, use "always" that's very slow but a bitsafer 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, anda background

# saving process (a background save or AOF log backgroundrewriting) is

# performing a lot of I/O against the disk, in some Linuxconfigurations

# Redis may block too long on the fsync() call. Note thatthere is no fix for

# this currently, as even performing fsync in a differentthread will block

# our synchronous write(2) call.

#

# In order to mitigate this problem it's possible to use thefollowing option

# that will prevent fsync() from being called in the mainprocess while a

# BGSAVE or BGREWRITEAOF is in progress.

#

# This means that while another child is saving, thedurability of Redis is

# the same as "appendfsync none". In practical terms, thismeans that it is

# possible to lose up to 30 seconds of log in the worstscenario (with the

# default Linux settings).

# 

# If you have latency problems turn this to "yes". Otherwiseleave it as

# "no" that is the safest pick from the point of view ofdurability.

no-appendfsync-on-rewrite no

# Automatic rewrite of the append only file.

# Redis is able to automatically rewrite the log fileimplicitly calling

# BGREWRITEAOF when the AOF log size grows by the specifiedpercentage.

# 

# This is how it works: Redis remembers the size of the AOFfile after the

# latest rewrite (if no rewrite has happened since therestart, the size of

# the AOF at startup is used).

#

# This base size is compared to the current size. If thecurrent size is

# bigger than the specified percentage, the rewrite istriggered. Also

# you need to specify a minimal size for the AOF file to berewritten, this

# is useful to avoid rewriting the AOF file even if thepercentage increase

# is reached but it is still pretty small.

#

# Specify a percentage of zero in order to disable theautomatic 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 thata script is

# still in execution after the maximum allowed time and willstart to

# reply to queries with an error.

#

# When a long running script exceed the maximum execution timeonly the

# SCRIPT KILL and SHUTDOWN NOSAVE commands are available. Thefirst can be

# used to stop a script that did not yet called writecommands. The second

# is the only way to shut down the server in the case a writecommands was

# already issue by the script but the user don't want to waitfor the natural

# termination of the script.

#

# Set it to 0 or a negative value for unlimited executionwithout warnings.

lua-time-limit 5000

################################## SLOW LOG###################################

# The Redis Slow Log is a system to log queries that exceededa specified

# execution time. The execution time does not include the I/Ooperations

# like talking with the client, sending the reply and soforth,

# but just the time needed to actually execute the command(this is the only

# stage of command execution where the thread is blocked andcan not serve

# other requests in the meantime).

# 

# You can configure the slow log with two parameters: onetells Redis

# what is the execution time, in microseconds, to exceed inorder for the

# command to get logged, and the other parameter is the lengthof the

# slow log. When a new command is logged the oldest one isremoved from the

# queue of logged commands.

# The following time is expressed in microseconds, so 1000000is equivalent

# to one second. Note that a negative number disables the slowlog, 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 willconsume memory.

# You can reclaim memory used by the slow log with SLOWLOGRESET.

slowlog-max-len 128

############################### ADVANCED CONFIG###############################

# Hashes are encoded using a memory efficient data structurewhen they have a

# small number of entries, and the biggest entry does notexceed a given

# threshold. These thresholds can be configured using thefollowing directives.

hash-max-ziplist-entries 512

hash-max-ziplist-value 64

# Similarly to hashes, small lists are also encoded in aspecial way in order

# to save a lot of space. The special representation is onlyused 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 iscomposed

# of just strings that happens to be integers in radix 10 inthe range

# of 64 bit signed integers.

# The following configuration setting sets the limit in thesize of the

# set in order to use this special memory savingencoding.

set-max-intset-entries 512

# Similarly to hashes and lists, sorted sets are alsospecially encoded in

# order to save a lot of space. This encoding is only usedwhen the length and

# elements of a sorted set are below the followinglimits:

zset-max-ziplist-entries 128

zset-max-ziplist-value 64

# Active rehashing uses 1 millisecond every 100 millisecondsof CPU time in

# order to help rehashing the main Redis hash table (the onemapping top-level

# keys to values). The hash table implementation Redis uses(see dict.c)

# performs a lazy rehashing: the more operation you run intoan hash table

# that is rehashing, the more rehashing "steps" are performed,so if the

# server is idle the rehashing is never complete and some morememory is used

# by the hash table.

# 

# The default is to use this millisecond 10 times every secondin order to

# active rehashing the main dictionaries, freeing memory whenpossible.

#

# If unsure:

# use "activerehashing no" if you have hard latencyrequirements and it is

# not a good thing in your environment that Redis can replyform time to time

# to queries with 2 milliseconds delay.

#

# use "activerehashing yes" if you don't have such hardrequirements but

# want to free memory asap when possible.

activerehashing yes

# The client output buffer limits can be used to forcedisconnection of clients

# that are not reading data from the server fast enough forsome reason (a

# common reason is that a Pub/Sub client can't consumemessages as fast as the

# publisher can produce them).

#

# The limit can be set differently for the three differentclasses of clients:

#

# normal -> normal clients

# slave  -> slave clients and MONITORclients

# pubsub -> clients subcribed to at least one pubsubchannel or pattern

#

# The syntax of every client-output-buffer-limit directive isthe following:

#

# client-output-buffer-limit

#

# A client is immediately disconnected once the hard limit isreached, or if

# the soft limit is reached and remains reached for thespecified number of

# seconds (continuously).

# So for instance if the hard limit is 32 megabytes and thesoft limit is

# 16 megabytes / 10 seconds, the client will get disconnectedimmediately

# if the size of the output buffers reach 32 megabytes, butwill also get

# disconnected if the client reaches 16 megabytes andcontinuously overcomes

# the limit for 10 seconds.

#

# By default normal clients are not limited because they don'treceive data

# without asking (in a push way), but just after a request, soonly

# asynchronous clients may create a scenario where data isrequested faster

# than it can read.

#

# Instead there is a default limit for pubsub and slaveclients, since

# subscribers and slaves receive data in a push fashion.

#

# Both the hard or the soft limit can be disabled by settingthem to zero.

client-output-buffer-limit normal 0 0 0

client-output-buffer-limit slave 256mb 64mb 60

client-output-buffer-limit pubsub 32mb 8mb 60

# Redis calls an internal function to perform many backgroundtasks, like

# closing connections of clients in timeot, purging expiredkeys that are

# never requested, and so forth.

#

# Not all tasks are perforemd with the same frequency, butRedis checks for

# tasks to perform accordingly to the specified "hz"value.

#

# By default "hz" is set to 10. Raising the value will usemore CPU when

# Redis is idle, but at the same time will make Redis moreresponsive when

# there are many keys expiring at the same time, and timeoutsmay be

# handled with more precision.

#

# The range is between 1 and 500, however a value over 100 isusually not

# a good idea. Most users should use the default of 10 andraise this up to

# 100 only in environments where very low latency isrequired.

hz 10

# When a child rewrites the AOF file, if the following optionis 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 incrementallyand 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 butalso 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

下面根据Redis之基础-1Redis2.6.16版本安装介绍之redis.conf配置文件详细说明

daemonize：

#是否以后台Daemon方式运行

pidfile：
# Pid文件位置

port：
# 监听的端口号

bind：
# 绑定的IP
# 例如：
# bind 0.0.0.0   监听本机所有的IP，远程主机也可以连接上
# bind 127.0.0.1 指定Redis 只接收来自于该IP地址的请求，如果不进行设置，那么将处理所有请求，在生产环境中
# 如果考虑设置安全，最好设置该项
# 建议：bind 127.0.0.1或者unixsocket /tmp/redis.sock

unixsocket：
# 指定Socket文件路径，使用Socket进行Redis连接

unixsocketperm： 
# 指定Socket文件的文件权限

timeout：
# 请求超时时间

tcp-keepalive：
# 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 

loglevel：
# log信息级别
# log 等级分为4 级，debug, verbose, notice,和warning。生产环境下一般开启notice

logfile：
# log文件位置

databases：
# 开启数据库的数量
# 可用数据库数，默认值为16，默认数据库存储在DB 0号ID库中，无特殊需求，建议仅设置一个数据库 databases1
# 查询数据库使用  SELECT
# dbid介于 0 到 'databases'-1 之间

save * *：
#保存快照的频率，第一个*表示多长时间，第二个*表示执行多少次写操作。在一定时间内执行一定数量的写操作时，自动保存快照，可设置多个条件
# 下面的例子将会进行把数据写入磁盘的操作:
# save 900 1
# save 300 10
# save 60 10000
# 900秒(15分钟)之后，且至少有1个key(次)变更
# 300秒(5分钟)之后，且至少有10个key(次)变更
# 60秒之后，且至少有10000个key(次)变更
# 注意：如果不需要写磁盘，则把所有 "save"设置注释掉，即实现全内存服务器。

stop-writes-on-bgsave-error：
# 后台存储错误是否停止写，yes和no选项

rdbcompression：
# 是否使用压缩，yes和no选项
# 当导出到 .rdb 数据库时是否用LZF压缩字符串对象
# 默认设置为 "yes"，
# 如果想节省CPU的话，可以把这个设置为 "no"，但是如果有可以压缩的key却没有压缩的话，那数据文件就会变得更大

rdbchecksum：
# 是否进行校验，yes和no选项

dbfilename：
# 数据快照文件名（只是文件名，不包括目录）

dir：
# 工作目录，本地数据库会写到这个目录下，文件名就是上面的 "dbfilename"的值。累加文件也放这里
# 注意你这里指定的必须是目录，不是文件名。数据快照的保存目录

slaveof：
# 指定从服务器地址

masterauth：
# 指定主服务器的密码（若主服务器设置了登录密码）

slave-serve-stale-data：
# slave行为状态，yes和no选项
# 当一个slave失去和master的连接，或者同步正在进行中，slave的行为有两种可能：
# 1) 如果 slave-serve-stale-data 设置为 "yes"(默认值)，slave会继续响应客户端请求，可能是正常数据，也可能是还没获得值的空数据。
# 2) 如果 slave-serve-stale-data 设置为 "no"，slave会回复"正在从master同步（SYNCwith master in progress）"来处理各种请求，除了 INFO 和 SLAVEOF 命令。

slave-read-only：
# 设置slave实例属性，yes和no选项
# 如果为yes,slave实例只读,如果为no,slave实例可读可写

slave-priority：
# 设置从节点的优先级
# 大致意思就是通过设置从节点的优先级，来决定从节点是否能扮演主节点的角色。优先级是0的将不会成为主节点

requirepass：
# 设置客户端连接后进行任何其他指定前需要使用的密码

appendonly：
# 是否开启appendonlylog，开启的话每次写操作会记一条log，这会提高数据抗风险能力，但影响效率
# 不使用AOF，AOF是另一种持久化方式，我没有使用的原因是这种方式并不能在服务器或磁盘损坏的情况下，保证数据可用性。
# 默认情况下，Redis会在后台异步的把数据库镜像备份到磁盘，但是该备份是非常耗时的，而且备份也不能很频繁，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
# append only 模式之后，redis 会把所接收到的每一次写操作请求都追加到appendonly.aof文件中，当redis 重新启动时，会从该文件恢复出之前的状态。但是这样会造成appendonly.aof 文件过大，所以redis还支持了BGREWRITEAOF 指令，对appendonly.aof 进行重新整理,包括yes和no选项。

appendfsync：
#appendonlylog如何同步到磁盘（三个选项，分别是每次写都强制调用fsync、每秒启用一次fsync、不调用fsync等待系统自己同步）
# appendfsync always
# appendfsync everysec
# appendfsync no

maxclients：
# 最大并发连接数，默认为一万，这个跟系统本身的 open-file-limit 有关；超过这个限制后，会提示：max numberof clients reached

no-appendfsync-on-rewrite：
# 设置日志重新功能，选项为yes和no，默认值是 no
# yes : 在日志重写时，不进行命令追加操作，而只是将其放在缓冲区里，避免与命令的追加造成Disk IO上的冲突。
# no  : 在日志重写时，命令追加操作照常进行。

auto-aof-rewrite-percentage：
auto-aof-rewrite-min-size：
# 自动重写只增文件。  
# Redis可以自动盲从的调用‘BGREWRITEAOF’来重写日志文件，如果日志文件增长了指定的百分比。  
# 它是这样工作的：每次rewrite后redis会记录日志文件的大小。（如果重启后没有重写后的大小，就默认用日志文件大小） 
# 这个基准日志大小和当前日志大小做比较。如果当前大小比指定的百分比，重写机制就会被触发。 
# 同时，你也要制定一个重写下线，用来避免增长百分比够了，但是日志文件还很小的情况。  
# 指定百分比为0可以注掉自动重写日志文件功能。 
# auto-aof-rewrite-percentage的默认值为100
# auto-aof-rewrite-min-size的默认值为64mb

lua-time-limit：
# 一个Lua脚本最长的执行时间为5000毫秒（5秒），如果为0或负数表示无限执行时间 

slowlog-log-slower-than：
# Redis慢查询日志可以记录超过指定时间的查询。运行时间不包括各种I/O时间。
#例如：连接客户端，发送响应数据等。只计算命令运行的实际时间（这是唯一一种命令运行线程阻塞而无法同时为其他请求服务的场景） 
# 你可以为慢查询日志配置两个参数：一个是超标时间，单位为微妙，记录超过个时间的命令。 
# 另一个是慢查询日志长度。当一个新的命令被写进日志的时候，最老的那个记录会被删掉。 
# 
# 下面的时间单位是微秒，所以1000000就是1秒。注意，负数时间会禁用慢查询日志，而0则会强制记录所有命令。
 
slowlog-max-len：
# 这个长度没有限制。只要有足够的内存就行。你可以通过 SLOWLOG RESET 来释放内存

hash-max-ziplist-entries：
hash-max-ziplist-value：
# 当有大量数据时，适合用哈希编码（需要更多的内存），元素数量上限不能超过给定限制
# 你可以通过以上两个选项来设定这些限制。 

list-max-ziplist-entries：
list-max-ziplist-value：
# 与哈希相类似，数据元素较少的情况下，可以用另一种方式来编码从而节省大量空间。
# 这种方式只有在符合以上限制的时候才可以用。

set-max-intset-entries：
# 还有这样一种特殊编码的情况：数据全是64位无符号整型数字构成的字符串。 
# 上面这个配置项就是用来限制这种情况下使用这种编码的最大上限的。

zset-max-ziplist-entries：
zset-max-ziplist-value：
# 与第一、第二种情况相似，有序序列也可以用一种特别的编码方式来处理，可节省大量空间 
# 这种编码只适合长度和元素都符合上面限制的有序序列。

activerehashing：
#哈希刷新，每100个CPU毫秒会拿出1个毫秒来刷新Redis的主哈希表（顶级键值映射表） 
#redis所用的哈希表实现（见dict.c）采用延迟哈希刷新机制：你对一个哈希表操作越多，哈希刷新操作就越频繁； 
# 反之，如果服务器非常不活跃那么也就是用点内存保存哈希表而已。 
# 
# 默认是每秒钟进行10次哈希表刷新，用来刷新字典，然后尽快释放内存。 
# 
# 建议： 
# 如果你对延迟比较在意的话就用 "activerehashingno"，每个请求延迟2毫秒不太好嘛。 
# 如果你不太在意延迟而希望尽快释放内存的话就设置 "activerehashing yes"。
# 重新哈希the main Redis hash table(the one mapping top-level keys tovalues)，这样会节省更多的空间。

client-output-buffer-limit：
# client-output-buffer-limit normal 0 0 0：
# 对客户端输出缓冲进行限制可以强迫那些就不从服务器读取数据的客户端断开连接。对于normal client，第一个0表示取消hardlimit，第二个0和第三个0表示取消soft limit，normalclient默认取消限制，因为如果没有寻问，他们是不会接收数据的 

client-output-buffer-limit：
# client-output-buffer-limit slave 256mb 64mb 60：
# 对于slave client和MONITERclient，如果client-output-buffer一旦超过256mb，又或者超过64mb持续60秒，那么服务器就会立即断开客户端连接

client-output-buffer-limit：
# client-output-buffer-limit pubsub 32mb 8mb 60：
# 对于pubsubclient，如果client-output-buffer一旦超过32mb，又或者超过8mb持续60秒，那么服务器就会立即断开客户端连接

hz：
# 键值使用频率分级 

aof-rewrite-incremental-fsync：
# 间隔写入AOF文件

1. ################################ 快照  #################################  
2. #  
3. # Save the DB on disk:保存数据库到磁盘  
4. #  
5. #   save <秒> <更新>  
6. #  
7. #   如果指定的秒数和数据库写操作次数都满足了就将数据库保存。  
8. #  
9. #   下面是保存操作的实例：  
10. #   900秒（15分钟）内至少1个key值改变（则进行数据库保存--持久化）  
11. #   300秒（5分钟）内至少10个key值改变（则进行数据库保存--持久化）  
12. #   60秒（1分钟）内至少10000个key值改变（则进行数据库保存--持久化）  
13. #  
14. #   注释：注释掉“save”这一行配置项就可以让保存数据库功能失效。  
15. #  
16. #   你也可以通过增加一个只有一个空字符串的配置项（如下面的实例）来去掉前面的“save”配置。  
17. #  
18. #   save ""  
19.   
20. save 900 1  
21. save 300 10  
22. save 60 10000  
23.   
24. #在默认情况下，如果RDB快照持久化操作被激活（至少一个条件被激活）并且持久化操作失败，Redis则会停止接受更新操作。  
25. #这样会让用户了解到数据没有被正确的存储到磁盘上。否则没人会注意到这个问题，可能会造成灾难。  
26. #  
27. #如果后台存储（持久化）操作进程再次工作，Redis会自动允许更新操作。  
28. #  
29. #然而，如果你已经恰当的配置了对Redis服务器的监视和备份，你也许想关掉这项功能。  
30. #如此一来即使后台保存操作出错,redis也仍然可以继续像平常一样工作。  
31. stop-writes-on-bgsave-error yes  
32.   
33. #是否在导出.rdb数据库文件的时候采用LZF压缩字符串和对象？  
34. #默认情况下总是设置成‘yes’， 他看起来是一把双刃剑。  
35. #如果你想在存储的子进程中节省一些CPU就设置成'no'，  
36. #但是这样如果你的kye/value是可压缩的，你的到处数据接就会很大。  
37. rdbcompression yes  
38.   
39. #从版本RDB版本5开始，一个CRC64的校验就被放在了文件末尾。  
40. #这会让格式更加耐攻击，但是当存储或者加载rbd文件的时候会有一个10%左右的性能下降，  
41. #所以，为了达到性能的最大化，你可以关掉这个配置项。  
42. #  
43. #没有校验的RDB文件会有一个0校验位，来告诉加载代码跳过校验检查。  
44. rdbchecksum yes  
45.   
46. # 导出数据库的文件名称  
47. dbfilename dump.rdb  
48.   
49. # 工作目录  
50. #  
51. # 导出的数据库会被写入这个目录，文件名就是上面'dbfilename'配置项指定的文件名。  
52. #   
53. # 只增的文件也会在这个目录创建（这句话没看明白）  
54. #   
55. # 注意你一定要在这个配置一个工作目录，而不是文件名称。  
56. dir /opt/redis-2.6.10/data