Docker redis cluster configuration

docker Installation and deployment redis

With 6 Cluster relationship of machines as an example ：

3 Lord 3 from redis Cluster configuration

Create a container

docker run -d --name=redis-node-1 --net host --privileged=true -v /data/server/docker_redis_share/redis-node-1/data:/data redis:6.2.1 --cluster-enabled yes --appendonly yes --port 6381
docker run -d --name=redis-node-2 --net host --privileged=true -v /data/server/docker_redis_share/redis-node-2/data:/data redis:6.2.1 --cluster-enabled yes --appendonly yes --port 6382
docker run -d --name=redis-node-3 --net host --privileged=true -v /data/server/docker_redis_share/redis-node-3/data:/data redis:6.2.1 --cluster-enabled yes --appendonly yes --port 6383
docker run -d --name=redis-node-4 --net host --privileged=true -v /data/server/docker_redis_share/redis-node-4/data:/data redis:6.2.1 --cluster-enabled yes --appendonly yes --port 6384
docker run -d --name=redis-node-5 --net host --privileged=true -v /data/server/docker_redis_share/redis-node-5/data:/data redis:6.2.1 --cluster-enabled yes --appendonly yes --port 6385
docker run -d --name=redis-node-6 --net host --privileged=true -v /data/server/docker_redis_share/redis-node-6/data:/data redis:6.2.1 --cluster-enabled yes --appendonly yes --port 6386

explain ：

--name                      Container name
--net host                  Using the host ip And port
--privileged=true        Get the root jurisdiction
-v /data/server/docker_redis_share/redis-node-1/data:/data      The container volume , Host address : Address of the container
redis:6.2.1                 redis Image and version number
--cluster-enabled yes      Open clusters
--appendonly yes        Turn on persistence
--port 6386                Port number

Building cluster relationships

Select any container to execute

[[email protected] server]# docker exec  -it  redis-node-1 /bin/bash
[email protected]:/data# redis-cli --cluster create 192.168.0.130:6381 192.168.0.130:6382 192.168.0.130:6383 192.168.0.130:6384 192.168.0.130:6385 192.168.0.130:6386 --cluster-replicas 1

explain ： 

192.168.0.130             The host machine ip Address
--cluster-replicas 1     For each master Create a slave node

Execution results ：

View cluster relationships

With 6381 Node as an example to view the cluster relationship

redis-cli  -p 6381

cluster info   View cluster information

 cluster nodes   View the cluster build status , Here you can also see the master-slave correspondence  

Master slave failover migration

Data read / write storage

The lower slot of the hash slot is divided into 3 paragraph ,3 Duan represents 3 Host computer ,key Where and how to realize the background sharing of data transmission in the cluster after entering

Appears when using the stand-alone command (error) MOVED 12706 192.168.0.130:6383 error Because it is higher than the slot range of the current container

At this time need Prevent route failure and add parameters -c

 

Different key There are different corresponding ranges of slots , So there will be redirects to other redis service

View cluster information

redis-cli --cluster check 192.168.0.130:6381

Failover migration

Current cluster status

Shut down the engine 6381, Get into 6382 View the cluster

Also, you can still find the newly deposited key

Restart 6381, View the cluster

  What you can see is 6381 After new startup ,6384 Is still master, To revert to the previous 3 Lord 3 From need to start 6381 Then close 6384 Start again in a few minutes 6384

Master slave capacity expansion

High concurrency 3 Lord 3 From being unable to meet the current data needs to be expanded to 4 Lord 4 Since then ,6387(master) Hang on 6388(slave) Next , How to allocate the slot of the hash slot

newly build 2 Nodes

docker run -d --name=redis-node-7 --net host --privileged=true -v /data/server/docker_redis_share/redis-node-7/data:/data redis:6.2.1 --cluster-enabled yes --appendonly yes --port 6387
docker run -d --name=redis-node-8 --net host --privileged=true -v /data/server/docker_redis_share/redis-node-8/data:/data redis:6.2.1 --cluster-enabled yes --appendonly yes --port 6388

Get into 6387 Containers

docker exec -it redis-node-7 /bin/bash

Will add 6387 node （ Empty slot number ） As master The node joins the original cluster

redis-cli --cluster add-node 192.168.0.130:6387 192.168.0.130:6381

View the cluster

redis-cli --cluster check 192.168.0.130:6387

Reassign slot numbers

command redis-cli --cluster reshard IP Address : Port number

 redis-cli --cluster reshard 192.168.0.130:6387

1. After the new node is added, the cards need to be reshuffled ,4 Nodes AA Distribute (16384/4=4096)

2. To assign to the newly added machine ( What you need to input is the node id Number )

Look at the cluster again

Why? 6387 yes 3 A new interval , It used to be continuous ： Reallocation costs are too high , So before 3 Each family sets aside a part , from 6381/6382/6383 Separate out the three old nodes 1364 A pit for the new node 6387

Master node 6387 Assign slave nodes 6388

command ： redis-cli --cluster add-node ip: new slave port ip: new master port --cluster-slave --cluster-master-id New host node id Number

redis-cli --cluster add-node 192.168.0.130:6388 192.168.0.130:6387 --cluster-slave --cluster-master-id ded65a8e2342b01efc6a8874946fef2412d2f55b

Look at the cluster again

redis-cli --cluster check 192.168.0.130:6381 

Finally, the cluster situation

Master slave volume reduction

 

Purpose ：6387（master） and 6388(slave) Offline

Detect cluster conditions , Get the slave 6388 node id Number

Delete 6388 From the node

command ： redis-cli --cluster del-node ip: Slave port   Slave node id

redis-cli --cluster del-node 192.168.0.130:6388 f4a2ede9a29eb7816bb065999a31427cae8f327c

Command execution result  

take 6387 Empty the slot number , Redistribution , Assign the cleared slot numbers to 6381

 redis-cli --cluster reshard 192.168.0.130:6381

Detect cluster conditions

redis-cli --cluster check 192.168.0.130:6381

( At this time, the 4096 All the slots are pointed out to 6381, It became 8192 Slots , It is equivalent to giving all 6381)

Delete 6387

redis-cli --cluster del-node 192.168.0.130:6387 ded65a8e2342b01efc6a8874946fef2412d2f55b

Detect cluster conditions

redis-cli --cluster check 192.168.0.130:6381