Redis 相關知識簡介

Redis 是一組介於數據庫與服務之間的中間件，提供的功能十分豐富。

redis是一個key-value存儲系統。和Memcached相似，它支持存儲的value類型相對更多，包括string(字符串)、list(鏈表)、set(集合)和zset(有序集合)。這些數據類型都支持push/pop、add/remove及取交集並集和差集及更豐富的操做，並且這些操做都是原子性的。在此基礎上，redis支持各類不一樣方式的排序。與memcached同樣，爲了保證效率，數據都是緩存在內存中。區別的是redis會週期性的把更新的數據寫入磁盤或者把修改操做寫入追加的記錄文件，而且在此基礎上實現了master-slave(主從)同步。

以上的就是redis官方的說明。也就是說這個redis是用來作緩存用的提升併發性。聽說能夠用來作消息服務，這個我還沒作出demo。

本文簡單記錄一下 redis的簡單搭建過程。不包含集羣。若是說有時間會加上，如何用redis搭建緩存集羣。

介紹一下環境：Centos 6

文件下載：http://download.redis.io/releases/ 

我選擇的是 redis-3.2.8.tar.gz

將這個包 在linux 的/opt/下解壓，並編譯安裝使用命令：

tar -zvxf redis-3.2.8.tar.gz 
#PREFIX 指定安裝路徑
make PREFIX=/usr/local/redis/ install

這樣 安裝好以後 在/usr/local/redis/下有一個bin目錄

這裏咱們能夠看到，主要服務文件是：redis-server 配置文件爲redis.conf（這個文件來自於 安裝包 咱們將安裝包裏面的一個redis.conf的文件拷貝到安裝目錄的bin目錄下）

啓動客戶端腳本爲:redis-cli

以後 咱們能夠直接使用 redis默認的策略啓動 

redis-server

這個默認策略啓動以後，整個服務隨着終端存在而存在，若是終端關閉整個redis服務也會關閉

因此咱們通常加載 自定義配置文件啓動

redis-server redis.conf

注意 要想可以在後臺運行redis 咱們須要修改redis.conf裏面的參數值

配置文件參數以下 參考至：http://www.cnblogs.com/kreo/p/4423362.html

# redis 配置文件示例
 
# 當你須要爲某個配置項指定內存大小的時候，必需要帶上單位，
# 一般的格式就是 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全部的 redis server 的標準配置模板，
# 但針對某些 server 又須要一些個性化的設置，
# 你可使用 include 來包含一些其餘的配置文件，這對你來講是很是有用的。
#
# 可是要注意哦，include 是不能被 config rewrite 命令改寫的
# 因爲 redis 老是以最後的加工線做爲一個配置指令值，因此你最好是把 include 放在這個文件的最前面，
# 以免在運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
 
################################ 經常使用 #####################################
 
# 默認狀況下 redis 不是做爲守護進程運行的，若是你想讓它在後臺運行，你就把它改爲 yes。
# 當redis做爲守護進程運行的時候，它會寫一個 pid 到 /var/run/redis.pid 文件裏面。
daemonize no
 
# 當redis做爲守護進程運行的時候，它會把 pid 默認寫到 /var/run/redis.pid 文件裏面，
# 可是你能夠在這裏本身制定它的文件位置。
pidfile /var/run/redis.pid
 
# 監聽端口號，默認爲 6379，若是你設爲 0 ，redis 將不在 socket 上監放任何客戶端鏈接。
port 6379
 
# TCP 監聽的最大容納數量
#
# 在高併發的環境下，你須要把這個值調高以免客戶端鏈接緩慢的問題。
# Linux 內核會一言不發的把這個值縮小成 /proc/sys/net/core/somaxconn 對應的值，
# 因此你要修改這兩個值才能達到你的預期。
tcp-backlog 511
 
# 默認狀況下，redis 在 server 上全部有效的網絡接口上監聽客戶端鏈接。
# 你若是隻想讓它在一個網絡接口上監聽，那你就綁定一個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 空閒多少秒以後關閉鏈接（0 就是無論它）
timeout 0
 
# tcp 心跳包。
#
# 若是設置爲非零，則在與客戶端缺少通信的時候使用 SO_KEEPALIVE 發送 tcp acks 給客戶端。
# 這個之全部有用，主要由兩個緣由：
#
# 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。
# 能夠是下面的這些值：
# 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 (僅僅一些重要的消息被記錄)
loglevel notice
 
# 指定日誌文件的位置
logfile ""
 
# 要想把日誌記錄到系統日誌，就把它改爲 yes，
# 也能夠可選擇性的更新其餘的syslog 參數以達到你的要求
# syslog-enabled no
 
# 設置 syslog 的 identity。
# syslog-ident redis
 
# 設置 syslog 的 facility，必須是 USER 或者是 LOCAL0-LOCAL7 之間的值。
# syslog-facility local0
 
# 設置數據庫的數目。
# 默認數據庫是 DB 0，你能夠在每一個鏈接上使用 select <dbid> 命令選擇一個不一樣的數據庫，
# 可是 dbid 必須是一個介於 0 到 databasees - 1 之間的值
databases 16
 
################################ 快照 ################################
#
# 存 DB 到磁盤：
#
#   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數據保存到磁盤
#
#   下面的例子的意思是：
#   900 秒內若是至少有 1 個 key 的值變化，則保存
#   300 秒內若是至少有 10 個 key 的值變化，則保存
#   60 秒內若是至少有 10000 個 key 的值變化，則保存
#　　
#   注意：你能夠註釋掉全部的 save 行來停用保存功能。
#   也能夠直接一個空字符串來實現停用：
#   save ""
 
save 900 1
save 300 10
save 60 10000
 
# 默認狀況下，若是 redis 最後一次的後臺保存失敗，redis 將中止接受寫操做，
# 這樣以一種強硬的方式讓用戶知道數據不能正確的持久化到磁盤，
# 不然就會沒人注意到災難的發生。
#
# 若是後臺保存進程從新啓動工做了，redis 也將自動的容許寫操做。
#
# 然而你要是安裝了靠譜的監控，你可能不但願 redis 這樣作，那你就改爲 no 好了。
stop-writes-on-bgsave-error yes
 
# 是否在 dump .rdb 數據庫的時候使用 LZF 壓縮字符串
# 默認都設爲 yes
# 若是你但願保存子進程節省點 cpu ，你就設置它爲 no ，
# 不過這個數據集可能就會比較大
rdbcompression yes
 
# 是否校驗rdb文件
rdbchecksum yes
 
# 設置 dump 的文件位置
dbfilename dump.rdb
 
# 工做目錄
# 例如上面的 dbfilename 只指定了文件名，
# 可是它會寫入到這個目錄下。這個配置項必定是個目錄，而不能是文件名。
dir ./
 
################################# 主從複製 #################################
 
# 主從複製。使用 slaveof 來讓一個 redis 實例成爲另外一個reids 實例的副本。
# 注意這個只須要在 slave 上配置。
#
# slaveof <masterip> <masterport>
 
# 若是 master 須要密碼認證，就在這裏設置
# masterauth <master-password>
 
# 當一個 slave 與 master 失去聯繫，或者複製正在進行的時候，
# slave 可能會有兩種表現：
#
# 1) 若是爲 yes ，slave 仍然會應答客戶端請求，但返回的數據多是過期，
#    或者數據多是空的在第一次同步的時候
#
# 2) 若是爲 no ，在你執行除了 info he salveof 以外的其餘命令時，
#    slave 都將返回一個 "SYNC with master in progress" 的錯誤，
#
slave-serve-stale-data yes
 
# 你能夠配置一個 slave 實體是否接受寫入操做。
# 經過寫入操做來存儲一些短暫的數據對於一個 slave 實例來講多是有用的，
# 由於相對從 master 從新同步數而言，據數據寫入到 slave 會更容易被刪除。
# 可是若是客戶端由於一個錯誤的配置寫入，也可能會致使一些問題。
#
# 從 redis 2.6 版起，默認 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實例的一個保護層。
slave-read-only yes
 
# Slaves 在一個預約義的時間間隔內發送 ping 命令到 server 。
# 你能夠改變這個時間間隔。默認爲 10 秒。
#
# repl-ping-slave-period 10
 
# The following option sets the replication timeout for:
# 設置主從複製過時時間
#
# 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.
# 這個值必定要比 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
 
# 設置主從複製容量大小。這個 backlog 是一個用來在 slaves 被斷開鏈接時
# 存放 slave 數據的 buffer，因此當一個 slave 想要從新鏈接，一般不但願所有從新同步，
# 只是部分同步就夠了，僅僅傳遞 slave 在斷開鏈接時丟失的這部分數據。
#
# 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 能夠斷開鏈接的時間就越長。
#
# 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 再也不鏈接 slaves，backlog 將被釋放。
#
# A value of 0 means to never release the backlog.
# 若是設置爲 0 ，意味着毫不釋放 backlog 。
#
# repl-backlog-ttl 3600
 
# 當 master 不能正常工做的時候，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，可是若是是 0 ， 那是意味着這個 slave 不可能被選中。
#
# 默認優先級爲 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.
# 
# 設置認證密碼
# 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 將關閉全部的新鏈接
# 併發送一個‘max number of clients reached’的錯誤。
#
# maxclients 10000
 
# 若是你設置了這個值，當緩存的數據容量達到這個值， redis 將根據你選擇的
# eviction 策略來移除一些 keys。
#
# 若是 redis 不能根據策略移除 keys ，或者是策略被設置爲 ‘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').
#
# 最大使用內存
# maxmemory <bytes>
 
# 最大內存策略，你有 5 個選擇。
# 
# volatile-lru -> remove the key with an expire set using an LRU algorithm
# volatile-lru -> 使用 LRU 算法移除包含過時設置的 key 。
# allkeys-lru -> remove any key accordingly to the LRU algorithm
# allkeys-lru -> 根據 LRU 算法移除全部的 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 過時，只是給寫入操做返回一個錯誤
# 
# 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 集羣  ###############################
#
# 啓用或停用集羣
# 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

其中

修改daemonize 爲yes 咱們就能夠後臺運行redis

port redis端口

bind 127.0.0.1 這個參數默認是 打開着 表示 只監控IP爲127.0.0.1的用戶鏈接也就是本機用戶。

若是想要其餘機器也能共用redis須要將這個bind註釋掉

# requirepass foobared 設置訪問密碼。修改foobared 爲你本身的密碼便可。

默認沒有密碼。若是加入密碼以後

客戶端經過redis-cli 去操做緩存 則須要帶上密碼 作爲參數，不然會報noauth authentication required

相關操做 ：

redis-cli -h(host) 127.0.0.1 -p(port) 6379 -a password 鏈接redis

redis-cli shutdown 關閉redis

以及添加開機啓動

echo "/usr/local/redis/bin/redis-server /usr/local/redis/bin/redis.conf &" >> rc.local

對String list set 的操做 咱們這裏不作贅述。

這樣咱們就將redis搭建好了。接下來 下一篇將會講述 Spring boot裏集成 redis的知識