|NO.Z.00262|——————————|CloudNative|——|KuberNetes&中间件容器化及helm.V09|——|中间件.v09|redis.v5.0.4|redis集群缩容扩容|

一、redis集群缩容与扩容

### --- redis集群扩容
~~~     查找对应的rediscluster的名称；自定义的资源类型

[root@k8s-master01 redis-cluster-operator]# kubectl get DistributedRedisCluster
NAME                              MASTERSIZE   STATUS    AGE
example-distributedrediscluster   3            Healthy   23m

### --- 进行扩容为4个节点
~~~     注：redis-cluster最少需要6个节点

[root@k8s-master01 redis-cluster-operator]# kubectl edit DistributedRedisCluster example-distributedrediscluster
spec:
  clusterReplicas: 1
  image: redis:5.0.4-alpine
  masterSize: 2                     // 更改参数为4，扩容1个cluster，总计8个实例

### --- 查看扩容的节点，可以看到4个cluster，加4个副本，共计8个实例

[root@k8s-master01 redis-cluster-operator]# kubectl get po -owide
NAME                                      READY   STATUS    RESTARTS   AGE     IP               NODE           NOMINATED NODE   READINESS GATES
drc-example-distributedrediscluster-0-0   1/1     Running   0          26m     172.25.92.118    k8s-master02   <none>           <none>
drc-example-distributedrediscluster-0-1   1/1     Running   0          25m     172.27.14.225    k8s-node02     <none>           <none>
drc-example-distributedrediscluster-1-0   1/1     Running   0          26m     172.27.14.224    k8s-node02     <none>           <none>
drc-example-distributedrediscluster-1-1   1/1     Running   0          26m     172.18.195.33    k8s-master03   <none>           <none>
drc-example-distributedrediscluster-2-0   1/1     Running   0          26m     172.17.125.15    k8s-node01     <none>           <none>
drc-example-distributedrediscluster-2-1   1/1     Running   0          26m     172.25.244.238   k8s-master01   <none>           <none>
drc-example-distributedrediscluster-3-0   1/1     Running   0          2m3s    172.17.125.16    k8s-node01     <none>           <none>
drc-example-distributedrediscluster-3-1   0/1     Running   0          70s     172.25.92.119    k8s-master02   <none>           <none>

### --- 连接到新扩容的redis实例中，查看它的配置文件
~~~     注：这个文件是集群的信息，若是没有进行持久化数据的；实例重启，这个文件就丢失了，
~~~     丢失后就找不到集群配置，就加入不到集群中。
~~~     若是没有进行持久化存储，这个文件需要备份

[root@k8s-master01 redis-cluster-operator]# kubectl exec -ti drc-example-distributedrediscluster-3-0 -- sh
/data # ls
nodes.conf      redis_password
/data # cat nodes.conf 
ffefefa2530a45001306bf06fcce848a2e5ae024 172.25.244.238:6379@16379 master - 0 1621419084000 0 connected 10923-16383
bb2d3469a7f370633a5221b2b23930bc4ee62c74 172.18.195.33:6379@16379 master - 0 1621419085581 1 connected 5461-10922
aeb52af5a8fcf67dfb16b7ae0ba58b7c14cdc0a5 172.17.125.15:6379@16379 master - 0 1621419086584 3 connected
8137400d26bf5a6c4cdb85b7bfc0a59fd45ab038 172.17.125.16:6379@16379 myself,master - 0 1621418609000 6 connected
26ca79cf7cff280de719c70d0b0d42c120bb9944 172.27.14.224:6379@16379 slave bb2d3469a7f370633a5221b2b23930bc4ee62c74 0 1621419084414 1 connected
d4820100214b0a9ff7a37ea8b2f7ee82db5d602a 172.27.14.225:6379@16379 slave 67c2a5b7672580c59dce271c3427d20bf04733f1 0 1621419086000 2 connected
48549e731f5ba4e28605a4bfe42ee6c18f8d2f83 172.25.92.119:6379@16379 master - 0 1621419085000 7 connected
67c2a5b7672580c59dce271c3427d20bf04733f1 172.25.92.118:6379@16379 master - 0 1621419085000 2 connected 0-5460
vars currentEpoch 7 lastVoteEpoch 0

二、redis集群缩容

### --- redis集群缩容为3个节点，共计6个实例

[root@k8s-master01 redis-cluster-operator]# kubectl edit DistributedRedisCluster example-distributedrediscluster
spec:
  clusterReplicas: 1
  image: redis:5.0.4-alpine
  masterSize: 3             // 更改参数为3，缩容1个cluster，总计6个实例

### --- 查看缩容后的实例数量
~~~     注：查看当前的redis实例数量为6个，说明已经删除成功

[root@k8s-master01 redis-cluster-operator]# kubectl get po  -owide
NAME                                      READY   STATUS    RESTARTS   AGE   IP               NODE           NOMINATED NODE   READINESS GATES
demo-nginx-6bdcdcc585-ph6wl               2/2     Running   0          8d    172.25.92.112    k8s-master02   <none>           <none>
demo-nginx-6bdcdcc585-wqh28               2/2     Running   0          8d    172.18.195.31    k8s-master03   <none>           <none>
drc-example-distributedrediscluster-0-0   1/1     Running   0          51m   172.25.92.118    k8s-master02   <none>           <none>
drc-example-distributedrediscluster-0-1   1/1     Running   0          50m   172.27.14.225    k8s-node02     <none>           <none>
drc-example-distributedrediscluster-1-0   1/1     Running   0          51m   172.27.14.224    k8s-node02     <none>           <none>
drc-example-distributedrediscluster-1-1   1/1     Running   0          50m   172.18.195.33    k8s-master03   <none>           <none>
drc-example-distributedrediscluster-2-0   1/1     Running   5          51m   172.17.125.15    k8s-node01     <none>           <none>
drc-example-distributedrediscluster-2-1   1/1     Running   0          51m   172.25.244.238   k8s-master01   <none>

### --- 进入redis容器中，查看配置文件
~~~     注：通过配置文件查看该集群数量为6个实例，说明缩容成功；配置文件已经更新了

/data # cat nodes.conf 
d4820100214b0a9ff7a37ea8b2f7ee82db5d602a 172.27.14.225:6379@16379 slave 67c2a5b7672580c59dce271c3427d20bf04733f1 0 1621420126000 4 connected
26ca79cf7cff280de719c70d0b0d42c120bb9944 172.27.14.224:6379@16379 slave bb2d3469a7f370633a5221b2b23930bc4ee62c74 0 1621420125330 5 connected
bb2d3469a7f370633a5221b2b23930bc4ee62c74 172.18.195.33:6379@16379 master - 0 1621420127384 1 connected 5461-10922
ffefefa2530a45001306bf06fcce848a2e5ae024 172.25.244.238:6379@16379 master - 0 1621420126000 0 connected 10923-16383
67c2a5b7672580c59dce271c3427d20bf04733f1 172.25.92.118:6379@16379 myself,master - 0 1621420124000 2 connected 0-5460
8137400d26bf5a6c4cdb85b7bfc0a59fd45ab038 172.17.125.16:6379@16379 myself,master - 0 1621418609000 6 connected

Walter Savage Landor:strove with none,for none was worth my strife.Nature I loved and, next to Nature, Art:I warm'd both hands before the fire of life.It sinks, and I am ready to depart

——W.S.Landor