docker搭建Redis3主3从集群并扩缩容

1. 创建6个Redis容器实例
docker run -d --name redis-node-1 --net host --privileged=true -v /opt/redis/share/redis-node-1:/data redis --cluster-enabled yes --appendonly yes --port 6381
docker run -d --name redis-node-2 --net host --privileged=true -v /opt/redis/share/redis-node-2:/data redis --cluster-enabled yes --appendonly yes --port 6382
docker run -d --name redis-node-3 --net host --privileged=true -v /opt/redis/share/redis-node-3:/data redis --cluster-enabled yes --appendonly yes --port 6383
docker run -d --name redis-node-4 --net host --privileged=true -v /opt/redis/share/redis-node-4:/data redis --cluster-enabled yes --appendonly yes --port 6384
docker run -d --name redis-node-5 --net host --privileged=true -v /opt/redis/share/redis-node-5:/data redis --cluster-enabled yes --appendonly yes --port 6385
docker run -d --name redis-node-6 --net host --privileged=true -v /opt/redis/share/redis-node-6:/data redis --cluster-enabled yes --appendonly yes --port 6386
	# 参数详解 --net host = 使用宿主机的ip和端口, 是默认选项

2. 构建集群
redis-cli --cluster create 10.122.1.86:6381 10.122.1.86:6382 10.122.1.86:6383 10.122.1.86:6384 10.122.1.86:6385 10.122.1.86:6386 --cluster-replicas 1		# 一一分配
yes
3. 查看集群状态(redis内执行)
cluster info		
cluster nodes	# 可以确定主从的对应关系
M		S
1		6
2		4
3		5
redis-cli --cluster check 10.122.1.86:6381	(容器内执行)

4.连接至集群中
docker exec -it redis-node-1 /bin/bash
redis-cli -p 6381 -c

5. 容错迁移, 假使某个master宕, 是否有slave上位
 docker stop redis-node-2		# 宿主机执行
 # check状态
cluster nodes 
 # 发现master,fail, 短暂等待再次check
cluster nodes
# 会发现原先属于master2的slave4上位, 变成master

1. 启动实例
docker run -d --name redis-node-7 --net host --privileged=true -v /opt/redis/share/redis-node-7:/data redis --cluster-enabled yes --appendonly yes --port 6387
docker run -d --name redis-node-8 --net host --privileged=true -v /opt/redis/share/redis-node-8:/data redis --cluster-enabled yes --appendonly yes --port 6388
2. 将6387节点作为master加入集群
docker exec -it redis-node-7  /bin/bash
redis-cli  --cluster add-node 10.122.1.86:6387 10.122.1.86:6381
redis-cli  --cluster check 10.122.1.86:6381发现6387已经作为新的master
3. 重新分配槽号

   How many slots do you want to move (from 1 to 16384)? 4096

   What is the receiving node ID?	c6822e309e97b70122ec8219334b28457bbd6845

   Source node #1: all

   Do you want to proceed with the proposed reshard plan (yes/no)? yes

   redis-cli  --cluster check 10.122.1.86:6381

# 发现6387节点具有4096个槽位(原本的3个节点各均匀分配一些出来)

1. 将6388作为6387的slave新增至集群
redis-cli --cluster add-node 10.122.1.86:6388 10.122.1.86:6387 --cluster-slave --cluster-master-id c6822e309e97b70122ec8219334b28457bbd6845
redis-cli -p 6381 -c
cluster nodes 	# 确认集群状态

1. 删除从机6388
redis-cli --cluster del-node 10.122.1.86:6388 1da4941694c45812027fc74e687d7de17ad798eb
2. 重分配槽位
2.1 方案1: 将6387的槽位分配给6382
	 redis-cli  --cluster reshard 10.122.1.86:6382
	 How many slots do you want to move (from 1 to 16384)? 4096
	 What is the receiving node ID? 4314fd868093beea918b8aabacca74f3800855e4
	 Source node #1: c6822e309e97b70122ec8219334b28457bbd6845
	 Source node #2: done
	 Do you want to proceed with the proposed reshard plan (yes/no)? yes
	 

   		 redis-cli  --cluster check 10.122.1.86:6381

# 发现6387已经没有槽位, 而6382有8192个槽位

1. 删除主机6387
redis-cli --cluster del-node 10.122.1.86:6387 c6822e309e97b70122ec8219334b28457bbd6845
2. 确认
redis-cli  --cluster check 10.122.1.86:6381