前言

redis 3.0之后版本支持redis-cluster集群，Redis-Cluster采用无中心结构，每个节点保存数据和整个集群状态,每个节点都和其他所有 节点连接。

其结构特点：

1、所有的redis节点彼此互联(PING-PONG机制),内部使用二进制协议优化传输速度和带宽。

2、节点的fail是通过集群中超过半数的节点检测失效时才生效。

3、客户端与redis节点直连,不需要中间proxy层.客户端不需要连接集群所有节点,连接集群中任何一个可用节点即可。

4、redis-cluster把所有的物理节点映射到[0-16383]slot上（不一定是平均分配）,cluster 负责维护node<->slot<->value。

5、Redis集群预分好16384个slot，当需要在 Redis 集群中放置一个 key-value 时，根据 CRC16(key) mod 16384的值，决定将一个key放到哪个slot中。

配置

环境简介：

部署6个redis节点，为3主3从。

每个节点添加cluster配置：

（修改8001端口到对应的端口就可以了）

cluster-enabled yes

cluster-config-file nodes-8001.conf

cluster-node-timeout 15000

protected-mode yes

port 8001

tcp-backlog 511

timeout 0

tcp-keepalive 300

daemonize yes

pidfile /opt/redis/logs/redis_8001.pid

loglevel notice

logfile "/opt/redis/logs/redis-8001.log"

databases 16

always-show-logo yes

stop-writes-on-bgsave-error yes

rdbcompression yes

rdbchecksum yes

dbfilename dump_8001.rdb

dir "/opt/redis/data"

slave-read-only yes

appendonly yes

appendfilename "appendonly_8001.aof"

appendfsync everysec

no-appendfsync-on-rewrite no

auto-aof-rewrite-percentage 100

auto-aof-rewrite-min-size 64mb

aof-load-truncated yes

aof-use-rdb-preamble no

lua-time-limit 5000

slowlog-log-slower-than 10000

slowlog-max-len 128

latency-monitor-threshold 0

hash-max-ziplist-entries 512

hash-max-ziplist-value 64

list-max-ziplist-size -2

list-compress-depth 0

set-max-intset-entries 512

zset-max-ziplist-entries 128

zset-max-ziplist-value 64

hll-sparse-max-bytes 3000

activerehashing yes

client-output-buffer-limit normal 0 0 0

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

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

hz 10

aof-rewrite-incremental-fsync yes

如果是测试也可以在一台机子上部署伪分布式集群。

启动6个节点

查看状态，这时候6个节点是没有握手的，使用redis-cli进行操作

/opt/redis/bin/redis-cli -p 8001 -c

#查看节点状态

cluster nodes

7ec63a08d2355448d16a84b502974832c52359e1 :8001@18001 myself,master - 0 0 0 connected

#添加节点

cluster meet 127.0.0.1 8002

cluster meet 127.0.0.1 8003

cluster meet 127.0.0.1 8004

cluster meet 127.0.0.1 8005

cluster meet 127.0.0.1 8006

#查看节点状态

cluster nodes

95ab86e82b78cce76ab40e5c5d738a2c68044340 127.0.0.1:8005@18005 master - 0 1534341796000 4 connected

7ec63a08d2355448d16a84b502974832c52359e1 127.0.0.1:8001@18001 myself,master - 0 1534341797000 2 connected

c971636e57a7a9bfc6537064fe438cb78b7d82e1 127.0.0.1:8006@18006 master - 0 1534341798286 0 connected

b12f7ab5c229fdf817aa7b5a4c534463ce223c62 127.0.0.1:8003@18003 master - 0 1534341796000 0 connected

3f4af91be1577d94d31fc5ec048d03c86b3c7837 127.0.0.1:8002@18002 master - 0 1534341796283 1 connected

83f9fa5903fd47cb993ff1f051a6a10218e15c2f 127.0.0.1:8004@18004 master - 0 1534341797285 3 connected

#分配slot

/opt/redis/bin/redis-cli -h 127.0.0.1 -p 8001 cluster addslots {0..5461}

/opt/redis/bin/redis-cli -h 127.0.0.1 -p 8002 cluster addslots {5462..10922}

/opt/redis/bin/redis-cli -h 127.0.0.1 -p 8003 cluster addslots {10923..16383}

#设置主从，后面一长串是上面看到节点的node_id

/opt/redis/bin/redis-cli -h 127.0.0.1 -p 8004 cluster replicate 7ec63a08d2355448d16a84b502974832c52359e1

/opt/redis/bin/redis-cli -h 127.0.0.1 -p 8005 cluster replicate 3f4af91be1577d94d31fc5ec048d03c86b3c7837

/opt/redis/bin/redis-cli -h 127.0.0.1 -p 8006 cluster replicate b12f7ab5c229fdf817aa7b5a4c534463ce223c62

#查看节点状态

cluster nodes

95ab86e82b78cce76ab40e5c5d738a2c68044340 127.0.0.1:8005@18005 slave 3f4af91be1577d94d31fc5ec048d03c86b3c7837 0 1534343095000 4 connected

7ec63a08d2355448d16a84b502974832c52359e1 127.0.0.1:8001@18001 myself,master - 0 1534343093000 2 connected 0-5461

c971636e57a7a9bfc6537064fe438cb78b7d82e1 127.0.0.1:8006@18006 slave b12f7ab5c229fdf817aa7b5a4c534463ce223c62 0 1534343093000 5 connected

b12f7ab5c229fdf817aa7b5a4c534463ce223c62 127.0.0.1:8003@18003 master - 0 1534343095702 5 connected 10923-16383

3f4af91be1577d94d31fc5ec048d03c86b3c7837 127.0.0.1:8002@18002 master - 0 1534343094699 1 connected 5462-10922

83f9fa5903fd47cb993ff1f051a6a10218e15c2f 127.0.0.1:8004@18004 slave 7ec63a08d2355448d16a84b502974832c52359e1 0 1534343093000 3 connected

总结

搭建redis cluster集群还是比较简单的，维护嘛！还在摸索，感觉还是codis的图形界面好设置。