Redis 集羣是一個提供在多個Redis間節點間共享數據的程序集.redis3.0以前，只支持主從同步的，如果主的掛了，寫入就成問題了。3.0出來後就可以很好幫我們解決這個問題。
目前redis 3.0還不穩定，如果要用在生產環境中，要慎重。
一，redis服務器說明
192.168.10.219 6379
192.168.10.219 6380
192.168.10.219 6381
192.168.10.220 6382
192.168.10.220 6383
192.168.10.220 6384
要讓集羣正常運作至少需要三個主節點，不過在剛開始試用集羣功能時， 強烈建議使用六個節點： 其中三個爲主節點， 而其餘三個則是各個主節點的從節點。所有用二臺機器，開6個redis進程，模擬6臺機器。
二，安裝ruby,rubygems
# yum -y install gcc openssl-devel libyaml-devel libffi-devel readline-devel zlib-devel gdbm-devel ncurses-devel gcc-c++ automake autoconf
# yum -y install ruby rubygems //安裝ruby rubygems
//換源
# gem source -l
# gem source --remove http://rubygems.org/
# gem sources -a http://ruby.taobao.org/
# gem source -l
# gem install redis --version 3.0.0 //安裝gem_redis
Successfully installed redis-3.0.0
1 gem installed
Installing ri documentation for redis-3.0.0...
Installing RDoc documentation for redis-3.0.0...
以前寫過一篇ruby on rails的文章，請參考：centos ruby on rails apache mysql 安裝配置詳解
喜歡手動編譯的人，可以參考這篇文章，安裝ruby.
三，安裝redis3.0.0
1，安裝redis
# wget http://download.redis.io/releases/redis-3.0.0.tar.gz
# tar -xvzf redis-3.0.0.tar.gz
# cd redis-3.0.0
# make && make install
# cd src
# cp redis-trib.rb /usr/local/bin
# mkdir /etc/redis
# mkdir /var/log/redis
上述操作要先在二臺機器上面都操作好。
2,配置redis
[root@slave2 redis-3.0.0]# vim redis.conf //解壓的根目錄，有redis.conf,做以下修改
port 6379
pidfile /var/run/redis-6379.pid
dbfilename dump-6379.rdb
appendfilename "appendonly-6379.aof"
cluster-config-file nodes-6379.conf
cluster-enabled yes
cluster-node-timeout 5000
appendonly yes
3，copy配置文件，並修改端口
# cp redis.conf /etc/redis/redis-6379.conf
# cp redis.conf /etc/redis/redis-6380.conf
# cp redis.conf /etc/redis/redis-6381.conf
# scp redis.conf 192.168.10.220:/etc/redis/redis-6382.conf
# scp redis.conf 192.168.10.220:/etc/redis/redis-6383.conf
# scp redis.conf 192.168.10.220:/etc/redis/redis-6384.conf
# sed -i "s/6379/6380/g" /etc/redis/redis-6380.conf
# sed -i "s/6379/6381/g" /etc/redis/redis-6381.conf
# sed -i "s/6379/6382/g" /etc/redis/redis-6382.conf
# sed -i "s/6379/6383/g" /etc/redis/redis-6383.conf
# sed -i "s/6379/6384/g" /etc/redis/redis-6384.conf
將配置文件分別copy到二臺機器上，並替換端口：
# cat redis-6380.conf |awk '{if($0 !~ /^$/ && $0 !~ /#/) {print $0}}' |grep 6380
pidfile /var/run/redis-6380.pid
port 6380
dbfilename dump-6380.rdb
appendfilename "appendonly-6380.aof"
cluster-config-file nodes-6380.conf
有5處修改端口的地方
4，啓動並查看redis
# redis-server /etc/redis/redis-6379.conf > /var/log/redis/redis-6379.log 2>&1 &
# redis-server /etc/redis/redis-6380.conf > /var/log/redis/redis-6380.log 2>&1 &
# redis-server /etc/redis/redis-6381.conf > /var/log/redis/redis-6381.log 2>&1 &
# redis-server /etc/redis/redis-6382.conf > /var/log/redis/redis-6382.log 2>&1 &
# redis-server /etc/redis/redis-6383.conf > /var/log/redis/redis-6383.log 2>&1 &
# redis-server /etc/redis/redis-6384.conf > /var/log/redis/redis-6384.log 2>&1 &
# netstat -tpnl |grep redis
tcp 0 0 0.0.0.0:6379 0.0.0.0:* LISTEN 7298/redis-server *
tcp 0 0 0.0.0.0:6380 0.0.0.0:* LISTEN 7299/redis-server *
tcp 0 0 0.0.0.0:6381 0.0.0.0:* LISTEN 7304/redis-server *
tcp 0 0 0.0.0.0:16379 0.0.0.0:* LISTEN 7298/redis-server *
tcp 0 0 0.0.0.0:16380 0.0.0.0:* LISTEN 7299/redis-server *
tcp 0 0 0.0.0.0:16381 0.0.0.0:* LISTEN 7304/redis-server *
tcp 0 0 :::6379 :::* LISTEN 7298/redis-server *
tcp 0 0 :::6380 :::* LISTEN 7299/redis-server *
tcp 0 0 :::6381 :::* LISTEN 7304/redis-server *
tcp 0 0 :::16379 :::* LISTEN 7298/redis-server *
tcp 0 0 :::16380 :::* LISTEN 7299/redis-server *
tcp 0 0 :::16381 :::* LISTEN 7304/redis-server *
[root@slave2 redis]# ll /etc/redis/
總用量 156
-rw-r--r-- 1 root root 0 4月 30 23:54 appendonly-6379.aof
-rw-r--r-- 1 root root 0 5月 1 00:08 appendonly-6380.aof
-rw-r--r-- 1 root root 0 5月 1 00:08 appendonly-6381.aof
-rw-r--r-- 1 root root 18 5月 1 00:08 dump-6379.rdb
-rw-r--r-- 1 root root 18 5月 1 00:08 dump-6380.rdb
-rw-r--r-- 1 root root 18 5月 1 00:08 dump-6381.rdb
-rw-r--r-- 1 root root 763 5月 1 00:08 nodes-6379.conf
-rw-r--r-- 1 root root 763 5月 1 00:08 nodes-6380.conf
-rw-r--r-- 1 root root 763 5月 1 00:08 nodes-6381.conf
-rw-r--r-- 1 root root 41412 4月 30 23:30 redis-6379.conf
-rw-r--r-- 1 root root 41412 4月 30 23:39 redis-6380.conf
-rw-r--r-- 1 root root 41412 4月 30 23:39 redis-6381.conf
所有節點都啓動成功，並不代表，他們就是集羣了。
四，創建集羣，並查看
1，創建redis集羣
# redis-trib.rb create --replicas 1 192.168.10.219:6379 192.168.10.219:6380 192.168.10.219:6381 192.168.10.220:6382 192.168.10.220:6383 192.168.10.220:6384
2，查看redis集羣狀態
[root@slave2 redis]# redis-trib.rb check 192.168.10.219:6379
Connecting to node 192.168.10.219:6379: OK
Connecting to node 192.168.10.220:6384: OK
Connecting to node 192.168.10.219:6381: OK
Connecting to node 192.168.10.220:6383: OK
Connecting to node 192.168.10.220:6382: OK
Connecting to node 192.168.10.219:6380: OK
>>> Performing Cluster Check (using node 192.168.10.219:6379)
M: d40d9a367c24784b0336c7b80fb4c87337e2cba6 192.168.10.219:6379
slots:5461-10922 (5462 slots) master
1 additional replica(s)
S: 5f00f163d0c0a540ea99daf004f55588a802327b 192.168.10.220:6384
slots: (0 slots) slave
replicates d40d9a367c24784b0336c7b80fb4c87337e2cba6
S: b3b1a848987b5a87a06888e126d5c9b16f871ff5 192.168.10.219:6381
slots: (0 slots) slave
replicates d2eb5a8a77f87888792428aed4692dfb907e7a1d
M: d2eb5a8a77f87888792428aed4692dfb907e7a1d 192.168.10.220:6383
slots:10923-16383 (5461 slots) master
1 additional replica(s)
M: a8eafe8b19d6a28c034917da13a43ce1230fe870 192.168.10.220:6382
slots:0-5460 (5461 slots) master
1 additional replica(s)
S: a87d207204a53ab599bf7f6ffb9d679d0eef4f25 192.168.10.219:6380
slots: (0 slots) slave
replicates a8eafe8b19d6a28c034917da13a43ce1230fe870
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.
到這兒，redis集羣就配置成功了
五，測試redis集羣
# redis-cli -c -p 6379 -h 192.168.10.219 //在219登錄
192.168.10.219:6379> set tank tank1 //設置測試值
-> Redirected to slot [4407] located at 192.168.10.220:6382
OK //直接轉向到220 6382端口，數據存到了220 6382，不過有點奇怪
192.168.10.220:6382> get tank //可以取到值
"tank1"
[root@manage redis]# redis-cli -c -p 6383 -h 192.168.10.220 //220機器，6383端口
192.168.10.220:6383> get tank
-> Redirected to slot [4407] located at 192.168.10.220:6382 //直接轉向220 6382端口
"tank1"
[root@manage redis]# ps aux |grep redis //查看進程
root 7310 0.2 0.9 137436 9724 pts/0 Sl Apr30 0:09 redis-server *:6382 [cluster]
root 7311 0.2 0.9 137436 9776 pts/0 Sl Apr30 0:09 redis-server *:6383 [cluster]
root 7316 0.2 0.9 137436 9944 pts/0 Sl Apr30 0:10 redis-server *:6384 [cluster]
root 7478 0.0 0.0 103256 812 pts/0 S+ 00:56 0:00 grep redis
[root@manage redis]# kill -9 7310 //關閉220 6382端口，看數據會不會丟失
[root@slave2 redis]# redis-trib.rb check 192.168.10.219:6379 //查看集羣情況，任何接口都行
Connecting to node 192.168.10.219:6379: OK
Connecting to node 192.168.10.220:6384: OK
Connecting to node 192.168.10.219:6381: OK
Connecting to node 192.168.10.220:6383: OK
Connecting to node 192.168.10.219:6380: OK
>>> Performing Cluster Check (using node 192.168.10.219:6379)
M: d40d9a367c24784b0336c7b80fb4c87337e2cba6 192.168.10.219:6379
slots:5461-10922 (5462 slots) master
1 additional replica(s)
S: 5f00f163d0c0a540ea99daf004f55588a802327b 192.168.10.220:6384
slots: (0 slots) slave
replicates d40d9a367c24784b0336c7b80fb4c87337e2cba6
S: b3b1a848987b5a87a06888e126d5c9b16f871ff5 192.168.10.219:6381
slots: (0 slots) slave
replicates d2eb5a8a77f87888792428aed4692dfb907e7a1d
M: d2eb5a8a77f87888792428aed4692dfb907e7a1d 192.168.10.220:6383
slots:10923-16383 (5461 slots) master
1 additional replica(s)
M: a87d207204a53ab599bf7f6ffb9d679d0eef4f25 192.168.10.219:6380
slots:0-5460 (5461 slots) master
0 additional replica(s)
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered. //變成，三主二從了
[root@slave2 redis]# redis-cli -c -p 6379 -h 192.168.10.219 //219登錄
192.168.10.219:6379> get tank
-> Redirected to slot [4407] located at 192.168.10.219:6380 //數據被轉到了6380節點了
"tank1"
經測試，集羣是可用的。