redis-cluster集群
Redis集群搭建的方式有多种，例如使用zookeeper等，但从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redis-cluster架构图如下：
其结构特点：
- 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。
- 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。
- 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。
- 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。
- Redis集群预分好16384个桶，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放到哪个桶中。
1.1 Redis Cluster主从模式
- redis cluster 为了保证数据的高可用性，加入了主从模式，一个主节点对应一个或多个从节点，主节点提供数据存取，从节点则是从主节点拉取数据备份，当这个主节点挂掉后，就会有这个从节点选取一个来充当主节点，从而保证集群不会挂掉。
- 上面那个例子里, 集群有ABC三个主节点, 如果这3个节点都没有加入从节点，如果B挂掉了，我们就无法访问整个集群了。A和C的slot也无法访问。
- 所以我们在集群建立的时候，一定要为每个主节点都添加了从节点, 比如像这样, 集群包含主节点A、B、C, 以及从节点A1、B1、C1, 那么即使B挂掉系统也可以继续正确工作。
- B1节点替代了B节点，所以Redis集群将会选择B1节点作为新的主节点，集群将会继续正确地提供服务。 当B重新开启后，它就会变成B1的从节点。
- 不过需要注意，如果节点B和B1同时挂了，Redis集群就无法继续正确地提供服务了。
redis架构如图：
- 10.0.0.61 Redis01
- 10.0.0.62 Redis02
- 10.0.0.63 Redis03
- 在每个节点搭建两个redis，在任意一个节点安装ruby环境
- 记得关闭防火墙，或者开放对应端口
1.2 在每个节点安装redis
[root@redis01 ~]# cd /usr/local/src/[root@redis01 src]# wget http://download.redis.io/releases/redis-3.2.8.tar.gz--2017-12-26 18:27:29-- http://download.redis.io/releases/redis-3.2.8.tar.gzResolving download.redis.io (download.redis.io)... 109.74.203.151Connecting to download.redis.io (download.redis.io)|109.74.203.151|:80... connected.HTTP request sent, awaiting response... 200 OKLength: 1547237 (1.5M) [application/x-gzip]Saving to: ‘redis-3.2.8.tar.gz’100%[==================================================================================================================================>] 1,547,237 32.3KB/s in 23s 2017-12-26 18:27:53 (64.7 KB/s) - ‘redis-3.2.8.tar.gz’ saved [1547237/1547237][root@redis01 src]# tar xf redis-3.2.8.tar.gz[root@redis01 src]# cd redis-3.2.8/[root@redis01 redis-3.2.8]# make[root@redis01 redis-3.2.8]# make PREFIX=/usr/local/redis_m install[root@redis01 ~]# echo "export PATH=/usr/local/redis_m/bin:$PATH" >>/etc/profile[root@redis01 ~]# source /etc/profile[root@redis01 ~]# cd /usr/local/redis_m/[root@redis01 redis_m]# mkdir -p conf[root@redis01 redis_m]# cp /usr/local/src/redis-3.2.8/redis.conf conf/
- 修改redis_m的redis.conf
bind 10.0.0.61protected-mode yesport 6379tcp-backlog 511timeout 0tcp-keepalive 300cluster-enabled yescluster-config-file nodes_6379.conf #启动首次生成cluster-node-timeout 15000 daemonize yessupervised nopidfile "/var/run/redis_6379.pid"loglevel noticelogfile ""databases 16save 900 1save 300 10save 60 10000stop-writes-on-bgsave-error yesrdbcompression yesrdbchecksum yesdbfilename "dump.rdb"dir "/usr/local/redis_m/conf"slave-serve-stale-data yesslave-read-only yesrepl-diskless-sync norepl-diskless-sync-delay 5repl-disable-tcp-nodelay noslave-priority 100appendonly noappendfilename "appendonly.aof"appendfsync everysecno-appendfsync-on-rewrite noauto-aof-rewrite-percentage 100auto-aof-rewrite-min-size 64mbaof-load-truncated yeslua-time-limit 5000slowlog-log-slower-than 10000slowlog-max-len 128latency-monitor-threshold 0notify-keyspace-events ""hash-max-ziplist-entries 512hash-max-ziplist-value 64list-max-ziplist-size -2list-compress-depth 0set-max-intset-entries 512zset-max-ziplist-entries 128zset-max-ziplist-value 64hll-sparse-max-bytes 3000activerehashing yesclient-output-buffer-limit normal 0 0 0client-output-buffer-limit slave 256mb 64mb 60client-output-buffer-limit pubsub 32mb 8mb 60hz 10aof-rewrite-incremental-fsync yes
在本机搭建第二个redis
[root@redis01 conf]# cd /usr/local/[root@redis01 conf]# cp -r redis_m redis_s#修改节点2 redis_s的配置文件bind 10.0.0.61protected-mode yesport 6380tcp-backlog 511timeout 0tcp-keepalive 300cluster-enabled yescluster-config-file nodes_6380.confcluster-node-timeout 15000daemonize yessupervised nopidfile "/var/run/redis_6380.pid"loglevel noticelogfile ""databases 16save 900 1save 300 10save 60 10000stop-writes-on-bgsave-error yesrdbcompression yesrdbchecksum yesdbfilename "dump.rdb"dir "/usr/local/redis_s/conf"slave-serve-stale-data yesslave-read-only yesrepl-diskless-sync norepl-diskless-sync-delay 5repl-disable-tcp-nodelay noslave-priority 100appendonly noappendfilename "appendonly.aof"appendfsync everysecno-appendfsync-on-rewrite noauto-aof-rewrite-percentage 100auto-aof-rewrite-min-size 64mbaof-load-truncated yeslua-time-limit 5000slowlog-log-slower-than 10000slowlog-max-len 128latency-monitor-threshold 0notify-keyspace-events ""hash-max-ziplist-entries 512hash-max-ziplist-value 64list-max-ziplist-size -2list-compress-depth 0set-max-intset-entries 512zset-max-ziplist-entries 128zset-max-ziplist-value 64hll-sparse-max-bytes 3000activerehashing yesclient-output-buffer-limit normal 0 0 0client-output-buffer-limit slave 256mb 64mb 60client-output-buffer-limit pubsub 32mb 8mb 60hz 10aof-rewrite-incremental-fsync yes
-
每台机器都部署两个redis，重复上述操作。
- 部署完成在任意节点安装ruby环境
[root@redis01 src]# pwd/usr/local/src/redis-3.2.8/src[root@redis01 src]# cp redis-trib.rb /usr/local/bin/[root@redis01 src]# yum -y install ruby ruby-devel rubygems rpm-build[root@redis01 src]# gem install redis --version 3.0.0Fetching: redis-3.0.0.gem (100%)Successfully installed redis-3.0.0Parsing documentation for redis-3.0.0Installing ri documentation for redis-3.0.01 gem installed #启动redis [root@redis01 ~]# redis-server /usr/local/redis_m/conf/redis.conf [root@redis01 ~]# redis-server /usr/local/redis_s/conf/redis.conf [root@redis01 ~]# netstat -lntup|grep redistcp 0 0 10.0.0.61:6379 0.0.0.0:* LISTEN 7226/redis-server 1 tcp 0 0 10.0.0.61:6380 0.0.0.0:* LISTEN 7230/redis-server 1 tcp 0 0 10.0.0.61:16379 0.0.0.0:* LISTEN 7226/redis-server 1 tcp 0 0 10.0.0.61:16380 0.0.0.0:* LISTEN 7230/redis-server 1
2 .1 创建集群
启动集群
[root@redis01 ~]# redis-trib.rb create --replicas 1 10.0.0.61:6379 10.0.0.62:6379 10.0.0.63:6379 10.0.0.61:6380 10.0.0.62:6380 10.0.0.63:6380>>> Creating cluster##省略M: 7876243e1de6e81316ff299d0cbd9f50dee6a6a6 10.0.0.61:6379 slots:0-5460 (5461 slots) master 1 additional replica(s)M: 98b24b670b08b6f87c805d7225738b2119d1c1f3 10.0.0.63:6379 slots:10923-16383 (5461 slots) master 1 additional replica(s)S: 2f8dde5cfb03dd02331abf0560c3ab2e6fcfee0b 10.0.0.63:6380 slots: (0 slots) slave replicates 98b24b670b08b6f87c805d7225738b2119d1c1f3S: a4212518794b6afacd9dc703a061bcba2ecd9683 10.0.0.62:6380 slots: (0 slots) slave replicates 7876243e1de6e81316ff299d0cbd9f50dee6a6a6S: ce3105e44480c1c312918b01f6415767adc1e253 10.0.0.61:6380 slots: (0 slots) slave replicates c3d233cd5aa613b271e117c43a8d2a3f7702cdb5M: c3d233cd5aa613b271e117c43a8d2a3f7702cdb5 10.0.0.62:6379 slots:5461-10922 (5462 slots) master 1 additional replica(s)[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.
进入到集群
[root@redis01 ~]# redis-cli -h 10.0.0.61 -c -p 6379
查看cluster集群
[root@redis01 ~]# redis-trib.rb check 10.0.0.61:6379