Redis 集群安装
我们使用一台机器，模拟6个redis实例来创建redis集群，其中3主3从。
创建目录，copy配置文件
[root@localhost bin]# cd /application/redis-3.2/
[root@localhost redis-3.2]# ls
bin conf dump.rdb
[root@localhost redis-3.2]# mkdir cluster
[root@localhost redis-3.2]# ls
bin cluster conf dump.rdb
[root@localhost redis-3.2]# cd cluster/
[root@localhost cluster]# ls
[root@localhost cluster]# ls
[root@localhost cluster]# mkdir {7000,7001,7002,7003,7004,7005}
[root@localhost cluster]# cp ../conf/redis.conf 7000
[root@localhost cluster]# cp ../conf/redis.conf 7001
[root@localhost cluster]# cp ../conf/redis.conf 7002
[root@localhost cluster]# cp ../conf/redis.conf 7003
[root@localhost cluster]# cp ../conf/redis.conf 7004
[root@localhost cluster]# cp ../conf/redis.conf 7005
2. 修改配置文件
[root@localhost cluster]# cd 7000 [root@localhost 7000]# vi redis.conf #做如下修改 port 7000 daemonize yes cluster-enabled yes cluster-config-file nodes-7000.conf cluster-node-timeout 5000 appendonly yes dir /application/redis-3.2/cluster/7000/
按照此方式修改7001~7005的配置文件，注意修改端口号。
3. 启动各个实例
[root@localhost cluster]# ls 7000 7001 7002 7003 7004 7005 [root@localhost cluster]# ../bin/redis-server 7000/redis.conf [root@localhost cluster]# ../bin/redis-server 7001/redis.conf [root@localhost cluster]# ../bin/redis-server 7002/redis.conf [root@localhost cluster]# ../bin/redis-server 7003/redis.conf [root@localhost cluster]# ../bin/redis-server 7004/redis.conf [root@localhost cluster]# ../bin/redis-server 7005/redis.conf [root@localhost cluster]# ps -ef | grep redis root 31949 1 0 12:00 ? 00:00:00 ../bin/redis-server 127.0.0.1:7000 [cluster] root 31954 1 0 12:00 ? 00:00:00 ../bin/redis-server 127.0.0.1:7001 [cluster] root 31977 1 0 12:01 ? 00:00:00 ../bin/redis-server 127.0.0.1:7002 [cluster] root 31982 1 0 12:01 ? 00:00:00 ../bin/redis-server 127.0.0.1:7003 [cluster] root 31986 1 0 12:01 ? 00:00:00 ../bin/redis-server 127.0.0.1:7004 [cluster] root 31991 1 0 12:01 ? 00:00:00 ../bin/redis-server 127.0.0.1:7005 [cluster] root 31996 31349 0 12:01 pts/2 00:00:00 grep redis
4. 创建集群
现在我们已经有了六个正在运行中的 Redis 实例， 接下来我们需要使用这些实例来创建集群， 并为每个节点编写配置文件。
通过使用 Redis 集群命令行工具redis-trib，编写节点配置文件的工作可以非常容易地完成redis-trib位于Redis 源码的src文件夹中，它是一个 Ruby 程序，这个程序通过向实例发送特殊命令来完成创建新集群，检查集群，或者对集群进行重新分片（reshared）等工作。
我们需要执行以下命令来创建集群：
[root@localhost src]# ./redis-trib.rb create --replicas 1 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005 /usr/bin/env: ruby: No such file or directory
系统中没有安装ruby，所以报上面的错误。
先安装ruby
[root@localhost yum.repos.d]# yum install ruby
[root@localhost yum.repos.d]# yum install rubygems
[root@localhost yum.repos.d]# gem install redis
Successfully installed redis-3.2.2
1 gem installed
Installing ri documentation for redis-3.2.2...
Installing RDoc documentation for redis-3.2.2...
再次创建集群
[root@localhost src]# ./redis-trib.rb create --replicas 1 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005 >>> Creating cluster >>> Performing hash slots allocation on 6 nodes... Using 3 masters: 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 Adding replica 127.0.0.1:7003 to 127.0.0.1:7000 Adding replica 127.0.0.1:7004 to 127.0.0.1:7001 Adding replica 127.0.0.1:7005 to 127.0.0.1:7002 M: ac733323e529323b04b57fb13ddcdeb7c7db23fd 127.0.0.1:7000 slots:0-5460 (5461 slots) master M: 8e96fae16b8d92911e579ade8050829567427c8b 127.0.0.1:7001 slots:5461-10922 (5462 slots) master M: 3c0f95416608ce682fa7a18ee782111a7c4effda 127.0.0.1:7002 slots:10923-16383 (5461 slots) master S: 855bdb49452a2be3a3ab0a72b5270d057a7f2c9f 127.0.0.1:7003 replicates ac733323e529323b04b57fb13ddcdeb7c7db23fd S: 7ab4da5d4c822ab55a1dff1d24a1ff83a0c98260 127.0.0.1:7004 replicates 8e96fae16b8d92911e579ade8050829567427c8b S: fbe78c944af98f9cfd75c4dae87201b9c2572c7a 127.0.0.1:7005 replicates 3c0f95416608ce682fa7a18ee782111a7c4effda 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 127.0.0.1:7000) M: ac733323e529323b04b57fb13ddcdeb7c7db23fd 127.0.0.1:7000 slots:0-5460 (5461 slots) master M: 8e96fae16b8d92911e579ade8050829567427c8b 127.0.0.1:7001 slots:5461-10922 (5462 slots) master M: 3c0f95416608ce682fa7a18ee782111a7c4effda 127.0.0.1:7002 slots:10923-16383 (5461 slots) master M: 855bdb49452a2be3a3ab0a72b5270d057a7f2c9f 127.0.0.1:7003 slots: (0 slots) master replicates ac733323e529323b04b57fb13ddcdeb7c7db23fd M: 7ab4da5d4c822ab55a1dff1d24a1ff83a0c98260 127.0.0.1:7004 slots: (0 slots) master replicates 8e96fae16b8d92911e579ade8050829567427c8b M: fbe78c944af98f9cfd75c4dae87201b9c2572c7a 127.0.0.1:7005 slots: (0 slots) master replicates 3c0f95416608ce682fa7a18ee782111a7c4effda [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered.
Redis自动选择主从。
5. 连接集群
redis-cli 也可以作为集群的客户端工具，要想访问集群，只需连接任意一个redis实例即可。使用-c参数
[root@localhost bin]# ./redis-cli -c -p 7000 127.0.0.1:7000>
127.0.0.1:7000> set name zhangsanfeng -> Redirected to slot [5798] located at 127.0.0.1:7001 OK 127.0.0.1:7001> get name "zhangsanfeng"
set 命令写数据，集群将数据写到7001实例上，当你使用get命令获取数据时，客户端即自动切换到7001端口。
redis-cli对集群的支持是非常基本的， 所以它总是依靠 Redis 集群节点来将它转向（redirect）至正确的节点。一个真正的（serious）集群客户端应该做得比这更好： 它应该用缓存记录起哈希槽与节点地址之间的映射（map）， 从而直接将命令发送到正确的节点上面。