redis.conf

# redis 配置檔案示例

 
# 當你需要為某個配置項指定記憶體大小的時候，必須要帶上單位，
# 通常的格式就是 1k 5gb 4m 等醬紫：
#
# 1k  => 1000 bytes
# 1kb => 1024 bytes
# 1m  => 1000000 bytes
# 1mb => 1024*1024 bytes
# 1g  => 1000000000 bytes
# 1gb => 1024*1024*1024 bytes
#
# 單位是不區分大小寫的，你寫 1K 5GB 4M 也行
 
################################## INCLUDES ###################################
 
# 假如說你有一個可用於所有的 redis server 的標準配置模板，
# 但針對某些 server 又需要一些個性化的設定，
# 你可以使用 include 來包含一些其他的配置檔案，這對你來說是非常有用的。
#
# 但是要注意哦，include 是不能被 config rewrite 命令改寫的
# 由於 redis 總是以最後的加工線作為一個配置指令值，所以你最好是把 include 放在這個檔案的最前面，
# 以避免在執行時覆蓋配置的改變，相反，你就把它放在後面（外國人真囉嗦）。
#
# include /path/to/local.conf
# include /path/to/other.conf
 
################################ 常用 #####################################
 
# 預設情況下 redis 不是作為守護程式執行的，如果你想讓它在後臺執行，你就把它改成 yes。
# 當redis作為守護程式執行的時候，它會寫一個 pid 到 /var/run/redis.pid 檔案裡面。
daemonize no
 
# 當redis作為守護程式執行的時候，它會把 pid 預設寫到 /var/run/redis.pid 檔案裡面，
# 但是你可以在這裡自己制定它的檔案位置。
pidfile /var/run/redis.pid
 
# 監聽埠號，預設為 6379，如果你設為 0 ，redis 將不在 socket 上監聽任何客戶端連線。
port 6379
 
# TCP 監聽的最大容納數量
#
# 在高併發的環境下，你需要把這個值調高以避免客戶端連線緩慢的問題。
# Linux 核心會一聲不響的把這個值縮小成 /proc/sys/net/core/somaxconn 對應的值，
# 所以你要修改這兩個值才能達到你的預期。
tcp-backlog 511
 
# 預設情況下，redis 在 server 上所有有效的網路介面上監聽客戶端連線。
# 你如果只想讓它在一個網路介面上監聽，那你就繫結一個IP或者多個IP。
#
# 示例，多個IP用空格隔開:
#
# bind 192.168.1.100 10.0.0.1
# bind 127.0.0.1
 
# 指定 unix socket 的路徑。
#
# unixsocket /tmp/redis.sock
# unixsocketperm 755
 
# 指定在一個 client 空閒多少秒之後關閉連線（0 就是不管它）
timeout 0
 
# tcp 心跳包。
#
# 如果設定為非零，則在與客戶端缺乏通訊的時候使用 SO_KEEPALIVE 傳送 tcp acks 給客戶端。
# 這個之所有有用，主要由兩個原因：
#
# 1) 防止死的 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.
# 推薦一個合理的值就是60秒
tcp-keepalive 0
 
# 定義日誌級別。
# 可以是下面的這些值：
# debug (適用於開發或測試階段)
# verbose (many rarely useful info, but not a mess like the debug level)
# notice (適用於生產環境)
# warning (僅僅一些重要的訊息被記錄)
loglevel notice
 
# 指定日誌檔案的位置
logfile ""
 
# 要想把日誌記錄到系統日誌，就把它改成 yes，
# 也可以可選擇性的更新其他的syslog 引數以達到你的要求
# syslog-enabled no
 
# 設定 syslog 的 identity。
# syslog-ident redis
 
# 設定 syslog 的 facility，必須是 USER 或者是 LOCAL0-LOCAL7 之間的值。
# syslog-facility local0
 
# 設定資料庫的數目。
# 預設資料庫是 DB 0，你可以在每個連線上使用 select <dbid> 命令選擇一個不同的資料庫，
# 但是 dbid 必須是一個介於 0 到 databasees - 1 之間的值
databases 16
 
################################ 快照 ################################
#
# 存 DB 到磁碟：
#
#   格式：save <間隔時間（秒）> <寫入次數>
#
#   根據給定的時間間隔和寫入次數將資料儲存到磁碟
#
#   下面的例子的意思是：
#   900 秒內如果至少有 1 個 key 的值變化，則儲存
#   300 秒內如果至少有 10 個 key 的值變化，則儲存
#   60 秒內如果至少有 10000 個 key 的值變化，則儲存
#　　
#   注意：你可以註釋掉所有的 save 行來停用儲存功能。
#   也可以直接一個空字串來實現停用：
#   save ""
 
save 900 1
save 300 10
save 60 10000
 
# 預設情況下，如果 redis 最後一次的後臺儲存失敗，redis 將停止接受寫操作，
# 這樣以一種強硬的方式讓使用者知道資料不能正確的持久化到磁碟，
# 否則就會沒人注意到災難的發生。
#
# 如果後臺儲存程式重新啟動工作了，redis 也將自動的允許寫操作。
#
# 然而你要是安裝了靠譜的監控，你可能不希望 redis 這樣做，那你就改成 no 好了。
stop-writes-on-bgsave-error yes
 
# 是否在 dump .rdb 資料庫的時候使用 LZF 壓縮字串
# 預設都設為 yes
# 如果你希望儲存子程式節省點 cpu ，你就設定它為 no ，
# 不過這個資料集可能就會比較大
rdbcompression yes
 
# 是否校驗rdb檔案
rdbchecksum yes
 
# 設定 dump 的檔案位置
dbfilename dump.rdb
 
# 工作目錄
# 例如上面的 dbfilename 只指定了檔名，
# 但是它會寫入到這個目錄下。這個配置項一定是個目錄，而不能是檔名。
dir ./
 
################################# 主從複製 #################################
 
# 主從複製。使用 slaveof 來讓一個 redis 例項成為另一個reids 例項的副本。
# 注意這個只需要在 slave 上配置。
#
# slaveof <masterip> <masterport>
 
# 如果 master 需要密碼認證，就在這裡設定
# masterauth <master-password>
 
# 當一個 slave 與 master 失去聯絡，或者複製正在進行的時候，
# slave 可能會有兩種表現：
#
# 1) 如果為 yes ，slave 仍然會應答客戶端請求，但返回的資料可能是過時，
#    或者資料可能是空的在第一次同步的時候
#
# 2) 如果為 no ，在你執行除了 info he salveof 之外的其他命令時，
#    slave 都將返回一個 "SYNC with master in progress" 的錯誤，
#
slave-serve-stale-data yes
 
# 你可以配置一個 slave 實體是否接受寫入操作。
# 通過寫入操作來儲存一些短暫的資料對於一個 slave 例項來說可能是有用的，
# 因為相對從 master 重新同步數而言，據資料寫入到 slave 會更容易被刪除。
# 但是如果客戶端因為一個錯誤的配置寫入，也可能會導致一些問題。
#
# 從 redis 2.6 版起，預設 slaves 都是隻讀的。
#
# 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.
# 注意：只讀的 slaves 沒有被設計成在 internet 上暴露給不受信任的客戶端。
# 它僅僅是一個針對誤用例項的一個保護層。
slave-read-only yes
 
# Slaves 在一個預定義的時間間隔內傳送 ping 命令到 server 。
# 你可以改變這個時間間隔。預設為 10 秒。
#
# repl-ping-slave-period 10
 
# The following option sets the replication timeout for:
# 設定主從複製過期時間
#
# 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.
# 這個值一定要比 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.
repl-disable-tcp-nodelay no
 
# 設定主從複製容量大小。這個 backlog 是一個用來在 slaves 被斷開連線時
# 存放 slave 資料的 buffer，所以當一個 slave 想要重新連線，通常不希望全部重新同步，
# 只是部分同步就夠了，僅僅傳遞 slave 在斷開連線時丟失的這部分資料。
#
# The biggest the replication backlog, the longer the time the slave can be
# disconnected and later be able to perform a partial resynchronization.
# 這個值越大，salve 可以斷開連線的時間就越長。
#
# The backlog is only allocated once there is at least a slave connected.
#
# 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.
# 在某些時候，master 不再連線 slaves，backlog 將被釋放。
#
# A value of 0 means to never release the backlog.
# 如果設定為 0 ，意味著絕不釋放 backlog 。
#
# repl-backlog-ttl 3600
 
# 當 master 不能正常工作的時候，Redis Sentinel 會從 slaves 中選出一個新的 master，
# 這個值越小，就越會被優先選中，但是如果是 0 ， 那是意味著這個 slave 不可能被選中。
#
# 預設優先順序為 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.
 
################################## 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.
# 
# 設定認證密碼
# 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.
 
################################### 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).
#
# 一旦達到最大限制，redis 將關閉所有的新連線
# 併傳送一個‘max number of clients reached’的錯誤。
#
# maxclients 10000
 
# 如果你設定了這個值，當快取的資料容量達到這個值， redis 將根據你選擇的
# eviction 策略來移除一些 keys。
#
# 如果 redis 不能根據策略移除 keys ，或者是策略被設定為 ‘noeviction’，
# redis 將開始響應錯誤給命令，如 set，lpush 等等，
# 並繼續響應只讀的命令，如 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').
#
# 最大使用記憶體
# maxmemory <bytes>
 
# 最大記憶體策略，你有 5 個選擇。
# 
# volatile-lru -> remove the key with an expire set using an LRU algorithm
# volatile-lru -> 使用 LRU 演算法移除包含過期設定的 key 。
# allkeys-lru -> remove any key accordingly to the LRU algorithm
# allkeys-lru -> 根據 LRU 演算法移除所有的 key 。
# 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
# noeviction -> 不讓任何 key 過期，只是給寫入操作返回一個錯誤
# 
# 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 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.
 
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
 
################################ REDIS 叢集  ###############################
#
# 啟用或停用叢集
# 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 does 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
 
# 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
 
############################# 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
 
# 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
# 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
 
# 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 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 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 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 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

（1）bind +IP繫結IP
例如：bind 127.0.0.1只能本地訪問，bind 0.0.0.0外網也可訪問
（2）port 6379預設監聽埠
（3）持久化 save 300 10，300秒內如果有10條key被該表，儲存一次。
（4）AOF和RDB備份機制
Dbfilename dump.rdb 儲存的檔案
AOF：儲存命令
RDB：儲存資料

（1）daemonize no 預設情況下redis不是守護程式，如果想後臺執行的話，將其改為yes。Redis作為守護程式執行時，會寫一個pid到var/run/redis.pid檔案裡面。
（2）tcp-backlog 511 TCP監聽的最大容量
（3）timeout 0指定一個client空閒多少秒之後關閉連線（0就是不管他）
（4）maxclients 10000 一旦達到最大限制，redis將關閉所有的新連線，會根據選擇的關閉策略來移除一些keys。
（5）maxmemory <bytes>最大使用記憶體，移除策略：
a)volatile-lru 使用LRU方法移除包含過期設定的key
b)allkeys -lru使用lru移除所有的key
c)Volatile-random 
d)Allkeys-random
e)Volatile-ttl移除最鄰近過期時間的key