redis集群安装部署

为什么要redis集群

参考： https://blog.youkuaiyun.com/shenjianxz/article/details/59775212

记录redis集群安装步骤

其实很简单

我这里在两台机子上 分别装了两个redis  redis安装简单  下载 解压即可

这里不用说了 参考 https://www.cnblogs.com/linjiqin/p/7451353.html

这里只想说下遇到的坑

创建集群就一个命令即可  这里说至少要3个主节点 3主3从

[root@localhost src]# ./redis-trib.rb create --replicas 1 192.168.56.102:7000 192.168.56.102:7001
>>> Creating cluster
*** ERROR: Invalid configuration for cluster creation.
*** Redis Cluster requires at least 3 master nodes.
*** This is not possible with 2 nodes and 1 replicas per node.
*** At least 6 nodes are required.
[2]+  完成                  ./redis-server ../../redis_cluster/7001/redis.conf

其中报ERROR:Error installing redis:redis requires Ruby version >= 2.2.2异常

这个可以参考 https://blog.youkuaiyun.com/qq_37595946/article/details/77800147 搞定  

成功如下

[root@localhost src]# ./redis-trib.rb create --replicas 1 192.168.56.102:7000 192.168.56.102:7001 192.168.56.102:7002 192.168.56.103:7000 192.168.56.103:7001 192.168.56.103:7002
>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
192.168.56.102:7000
192.168.56.103:7000
192.168.56.102:7001
Adding replica 192.168.56.103:7001 to 192.168.56.102:7000
Adding replica 192.168.56.102:7002 to 192.168.56.103:7000
Adding replica 192.168.56.103:7002 to 192.168.56.102:7001
M: cc8b991c85f2982bf9ad99e22494a4fd6695edd1 192.168.56.102:7000
   slots:0-5460 (5461 slots) master
M: ccea4ee6dc0e5739c099c131292b0d007f6d3c82 192.168.56.102:7001
   slots:10923-16383 (5461 slots) master
S: cb1ad176e100f80926f67df1e44e16bd0b73a497 192.168.56.102:7002
   replicates e14229d0227bc32aa20db283af4394f65284d70a
M: e14229d0227bc32aa20db283af4394f65284d70a 192.168.56.103:7000
   slots:5461-10922 (5462 slots) master
S: 583ce7b5449aae2878a0b0028e99072a9bb116b9 192.168.56.103:7001
   replicates cc8b991c85f2982bf9ad99e22494a4fd6695edd1
S: c14c17037d1e3f9a69ba8e98a0375380ab88ea1f 192.168.56.103:7002
   replicates ccea4ee6dc0e5739c099c131292b0d007f6d3c82
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 192.168.56.102:7000)
M: cc8b991c85f2982bf9ad99e22494a4fd6695edd1 192.168.56.102:7000
   slots:0-5460 (5461 slots) master
   1 additional replica(s)
M: ccea4ee6dc0e5739c099c131292b0d007f6d3c82 192.168.56.102:7001
   slots:10923-16383 (5461 slots) master
   1 additional replica(s)
S: c14c17037d1e3f9a69ba8e98a0375380ab88ea1f 192.168.56.103:7002
   slots: (0 slots) slave
   replicates ccea4ee6dc0e5739c099c131292b0d007f6d3c82
S: 583ce7b5449aae2878a0b0028e99072a9bb116b9 192.168.56.103:7001
   slots: (0 slots) slave
   replicates cc8b991c85f2982bf9ad99e22494a4fd6695edd1
S: cb1ad176e100f80926f67df1e44e16bd0b73a497 192.168.56.102:7002
   slots: (0 slots) slave
   replicates e14229d0227bc32aa20db283af4394f65284d70a
M: e14229d0227bc32aa20db283af4394f65284d70a 192.168.56.103:7000
   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.

看到这个就成功了 

这里说下     通过client添加数据，如果key正好落在client对应的节点，就没有转发消息。否则，你会看到有一个转发消息。

[root@localhost src]# redis-cli -c -h 192.168.56.103 -p 7001
192.168.56.103:7001> set kkk  kkkkkk
-> Redirected to slot [8583] located at 192.168.56.103:7000
OK
192.168.56.103:7000> 

由于103:7001是slave  会转到它对应的master上去。

整个集群中  key 具有唯一性  比如 在一个master上 set  k  kkk   在另外一个master上 set  k  kkkkk  那么  这时会转到刚才第一个master那里去。

master down掉了后 slave自动切为master

记录下，仅此而已。