一、概述

Redis3.0版本之後支援Cluster，目前redis cluster支援的特性有：

節點自動發現，slave->master 選舉,叢集容錯，Hot resharding:線上分片
進群管理:cluster xxx，基於配置(nodes-port.conf)的叢集管理，ASK 轉向/MOVED 轉向機制.

二、redis cluster安裝

1、下載和解包

cd /usr/local/
wget http://download.redis.io/releases/redis-4.0.1.tar.gz
 tar -xvzf redis-4.0.1.tar.gz

2、 編譯安裝

 cd redis-4.0.1
 make && make install

3、建立redis節點

選擇2臺伺服器，分別為：192.168.59.131，192.168..59.130.每分伺服器有3個節點。

先在192.168.59.131建立3個節點：

  cd /usr/local/
//建立叢集目錄
  mkdir redis_cluster  
//分別代表三個節點    其對應埠 7000 7001 7002
  mkdir 7000 7001 7002  
 //以建立7000節點為例，拷貝到7000目錄
 cp /usr/local/redis-4.0.1/redis.conf  ./redis_cluster/7000/   
 //拷貝到7001目錄
 cp /usr/local/redis-4.0.1/redis.conf  ./redis_cluster/7001/   
 //拷貝到7002目錄
 cp /usr/local/redis-4.0.1/redis.conf  ./redis_cluster/7002/ 
 

分別對7001，7002、7003資料夾中的3個檔案修改對應的配置

daemonize    yes                             //redis後臺執行
pidfile  /var/run/redis_7000.pid         //pidfile檔案對應7000,7002,7003
bind 192.168.59.131                         //繫結ip地址
port  7000                                          //埠7000,7002,7003
cluster-enabled  yes                           //開啟叢集  把註釋#去掉
cluster-config-file  nodes_7000.conf   //叢集的配置  配置檔案首次啟動自動生成 7000,7001,7002
cluster-node-timeout  5000                //請求超時  設定5秒夠了
appendonly  yes                          //aof日誌開啟  有需要就開啟，它會每次寫操作都記錄一條日誌
 

在192.168.59.130建立3個節點：對應的埠改為7003,7004,7005.配置對應的改一下就可以了
4、兩臺機啟動各節點

第一臺機器上執行
redis-server redis_cluster/7000/redis.conf
redis-server redis_cluster/7001/redis.conf
redis-server redis_cluster/7002/redis.conf
 
另外一臺機器上執行
redis-server redis_cluster/7003/redis.conf
redis-server redis_cluster/7004/redis.conf
redis-server redis_cluster/7005/redis.conf 

5、檢視服務

  ps -ef | grep redis   #檢視是否啟動成功

 netstat -tnlp | grep redis #可以看到redis監聽埠

三、建立叢集

前面已經準備好了搭建叢集的redis節點，接下來我們要把這些節點都串連起來搭建叢集。
官方提供了一個工具：redis-trib.rb(/usr/local/redis-4.0.1/src/redis-trib.rb) 看字尾就知道它是用ruby寫的一個程式，所以我們還得安裝ruby.

yum -y install ruby ruby-devel rubygems rpm-build

再用 gem 這個命令來安裝 redis介面 gem是ruby的一個工具包.

gem install redis
接下來執行一下redis-trib.rb

[root@localhost local]# /usr/local/redis-4.0.1/src/redis-trib.rb
Usage: redis-trib <command> <options> <arguments ...>

  create          host1:port1 ... hostN:portN
                  --replicas <arg>
  check           host:port
  info            host:port
  fix             host:port
                  --timeout <arg>
  reshard         host:port
                  --from <arg>
                  --to <arg>
                  --slots <arg>
                  --yes
                  --timeout <arg>
                  --pipeline <arg>
  rebalance       host:port
                  --weight <arg>
                  --auto-weights
                  --use-empty-masters
                  --timeout <arg>
                  --simulate
                  --pipeline <arg>
                  --threshold <arg>
  add-node        new_host:new_port existing_host:existing_port
                  --slave
                  --master-id <arg>
  del-node        host:port node_id
  set-timeout     host:port milliseconds
  call            host:port command arg arg .. arg
  import          host:port
                  --from <arg>
                  --copy
                  --replace
  help            (show this help)

For check, fix, reshard, del-node, set-timeout you can specify the host and port of any working node in the cluster.

確認所有的節點都啟動，接下來使用引數create 建立 (在192.168.59.131中來建立)

/usr/local/redis-4.0.1/src/redis-trib.rb create --replicas 1 192.168.59.131:7000 192.168.59.131:7001 192.168.59.131:7003 192.168.59.130:7003 192.168.59.130:7004 192.168.59.130:7005

--replicas 1 表示 自動為每一個master節點分配一個slave節點 上面有6個節點，程式會按照一定規則生成 3個master（主）3個slave(從)

防火牆一定要開放監聽的埠，否則會建立失敗。
執行中，提示Can I set the above configuration? (type 'yes' to accept): yes //輸入yes

[root@localhost local]#  /usr/local/redis-4.0.1/src/redis-trib.rb  create  --replicas  1  192.168.59.131:7000 192.168.59.131:7001  192.168.59.131:7003 192.168.59.130:7003  192.168.59.130:7004  192.168.59.130:7005
>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.59.131:7000
192.168.59.130:7003
192.168.59.131:7001
Adding replica 192.168.59.130:7004 to 192.168.59.131:7000
Adding replica 192.168.59.131:7002 to 192.168.59.130:7003
Adding replica 192.168.59.130:7005 to 192.168.59.131:7001
M: 048937fd4ac542c135e7527f681be12348e8c8d0 192.168.59.131:7000
   slots:0-5460 (5461 slots) master
M: 2039bc32bf55d21d74296cdc91a316022a7afc4b 192.168.59.131:7001
   slots:10923-16383 (5461 slots) master
S: 76514c28d0a40f9751ccaf117d1f8f1d0878475a 192.168.59.131:7002
   replicates a58a304964ff10d10f4323341f7084c9f60f5124
M: a58a304964ff10d10f4323341f7084c9f60f5124 192.168.59.130:7003
   slots:5461-10922 (5462 slots) master
S: 7512d76b416d09619d3b639a94945a676d7b8826 192.168.59.130:7004
   replicates 048937fd4ac542c135e7527f681be12348e8c8d0
S: 7824b9721cb21de60c8d132d668fd3ac5c4eae49 192.168.59.130:7005
   replicates 2039bc32bf55d21d74296cdc91a316022a7afc4b
Can I set the above configuration? (type 'yes' to accept): yes
>>> Nodes configuration updated
>>> Assign a different config epoch to each node
>>> Sending CLUSTER MEET messages to join the cluster
Waiting for the cluster to join..
>>> Performing Cluster Check (using node 192.168.59.131:7000)
M: 048937fd4ac542c135e7527f681be12348e8c8d0 192.168.59.131:7000
   slots:0-5460 (5461 slots) master
   1 additional replica(s)
S: 76514c28d0a40f9751ccaf117d1f8f1d0878475a 192.168.59.131:7002
   slots: (0 slots) slave
   replicates a58a304964ff10d10f4323341f7084c9f60f5124
M: a58a304964ff10d10f4323341f7084c9f60f5124 192.168.59.130:7003
   slots:5461-10922 (5462 slots) master
   1 additional replica(s)
S: 7512d76b416d09619d3b639a94945a676d7b8826 192.168.59.130:7004
   slots: (0 slots) slave
   replicates 048937fd4ac542c135e7527f681be12348e8c8d0
M: 2039bc32bf55d21d74296cdc91a316022a7afc4b 192.168.59