搭建好集群之后，为了扩容需要再加入一个节点。那就再复制一个7006，改为相应的redis.conf（复制了改个port就好，如果复制的redis之前属于集群，需要把关联的node.conf之类的去掉）
[root@localhost 7006]# vim redis.conf [root@localhost 7006]# src/redis-server redis.conf [root@localhost 7006]# ps -ef | grep redis root 2993 2959 0 15:48 pts/0 00:00:00 src/redis-server *:6379 root 2999 1 0 15:49 ? 00:00:00 src/redis-server *:7000 [cluster] root 3006 1 0 15:49 ? 00:00:00 src/redis-server *:7001 [cluster] root 3013 1 0 15:49 ? 00:00:00 src/redis-server *:7002 [cluster] root 3017 1 0 15:50 ? 00:00:00 src/redis-server *:7003 [cluster] root 3021 1 0 15:50 ? 00:00:00 src/redis-server *:7004 [cluster] root 3028 1 0 15:50 ? 00:00:00 src/redis-server *:7005 [cluster] root 3061 1 0 15:59 ? 00:00:00 src/redis-server *:7006 [cluster]
（1）添加节点
很简单的一句命令： 前面是地址是新加入的一台redis，后面是属于之前集群的任意一台。
[root@localhost 7006]# src/redis-trib.rb add-node 127.0.0.1:7006 127.0.0.1:7001
>>> Adding node 127.0.0.1:7006 to cluster 127.0.0.1:7001 Connecting to node 127.0.0.1:7001: OK Connecting to node 127.0.0.1:7004: OK Connecting to node 127.0.0.1:7002: OK Connecting to node 127.0.0.1:7005: OK Connecting to node 127.0.0.1:7000: OK Connecting to node 127.0.0.1:7003: OK >>> Performing Cluster Check (using node 127.0.0.1:7001) M: 0bbc46d087d7256fb7b71ca35871446e29926afa 127.0.0.1:7001 slots:5461-10922 (5462 slots) master 1 additional replica(s) S: ec376f305428afde24aa363919a863f01908c140 127.0.0.1:7004 slots: (0 slots) slave replicates 0bbc46d087d7256fb7b71ca35871446e29926afa M: 0b521aa8664b2e51475470230f3a975bdd4d1909 127.0.0.1:7002 slots:10923-16383 (5461 slots) master 1 additional replica(s) S: d1a7c6485909a119a1c276f3972b8ae3f93e52d7 127.0.0.1:7005 slots: (0 slots) slave replicates 0b521aa8664b2e51475470230f3a975bdd4d1909 M: 9b7b98c4bf2517e4f172a895b5728d13bef62952 127.0.0.1:7000 slots:0-5460 (5461 slots) master 1 additional replica(s) S: ee95130f0aed20c62881df8070d7690c4608a7cc 127.0.0.1:7003 slots: (0 slots) slave replicates 9b7b98c4bf2517e4f172a895b5728d13bef62952 [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. Connecting to node 127.0.0.1:7006: OK >>> Send CLUSTER MEET to node 127.0.0.1:7006 to make it join the cluster. [OK] New node added correctly.
可以任意进入一台机器来查看是否添加了新的节点，会发现刚刚添加的节点并没有托管任何的哈希槽，原因是里面还木有数据了。增加从节点只需要加上--slave参数
[root@localhost 7006]# src/redis-cli -c -p 7001 127.0.0.1:7001> cluster nodes 0bbc46d087d7256fb7b71ca35871446e29926afa 127.0.0.1:7001 myself,master - 0 0 2 connected 5461-10922 32cc36d5deead5d8eb3208120d6f38358c9b6a55 127.0.0.1:7006 master - 0 1437992923735 0 connected ec376f305428afde24aa363919a863f01908c140 127.0.0.1:7004 slave 0bbc46d087d7256fb7b71ca35871446e29926afa 0 1437992924736 5 connected 0b521aa8664b2e51475470230f3a975bdd4d1909 127.0.0.1:7002 master - 0 1437992924736 3 connected 10923-16383 d1a7c6485909a119a1c276f3972b8ae3f93e52d7 127.0.0.1:7005 slave 0b521aa8664b2e51475470230f3a975bdd4d1909 0 1437992922732 6 connected 9b7b98c4bf2517e4f172a895b5728d13bef62952 127.0.0.1:7000 master - 0 1437992923234 1 connected 0-5460 ee95130f0aed20c62881df8070d7690c4608a7cc 127.0.0.1:7003 slave 9b7b98c4bf2517e4f172a895b5728d13bef62952 0 1437992924236 4 connected
（2）删除节点
删除节点之前首先要保证节点中没有数据，如果有数据需要分片，把数据转移走。后面跟着的id用cluster nodes 就能查看到对应的啦~
删除有数据的我还需要研究研究。。。因为一些很拙计的原因~~， ./redis-trib.rb reshard 127.0.0.1:9003 这句是转移时讲数据分配到那些哈希槽下的命令。
[root@localhost 7006]# src/redis-trib.rb del-node 127.0.0.1:7001 'c8ed852a52863e941a6e63037e018eb2952b776a' >>> Removing node c8ed852a52863e941a6e63037e018eb2952b776a from cluster 127.0.0.1:7001 Connecting to node 127.0.0.1:7001: OK Connecting to node 127.0.0.1:7004: OK Connecting to node 127.0.0.1:7002: OK Connecting to node 127.0.0.1:7005: OK Connecting to node 127.0.0.1:7006: OK Connecting to node 127.0.0.1:7000: OK Connecting to node 127.0.0.1:7003: OK >>> Sending CLUSTER FORGET messages to the cluster... >>> SHUTDOWN the node.
好的，假装他删的很顺利~~
还有需要补充的之后继续补充......