Docker learning - redis cluster -3 master and 3 slave - capacity expansion - capacity reduction building

Illustration

//  First step ： Start six Redis machine 
docker run -d --name=redis-node-1 --net host --privileged=true -v /www/server/redis_master_slave/master_slave1/master:/data redis:latest --cluster-enabled yes --appendonly yes --port 6381

docker run -d --name=redis-node-2 --net host --privileged=true -v /www/server/redis_master_slave/master_slave2/master:/data redis:latest --cluster-enabled yes --appendonly yes --port 6382

docker run -d --name=redis-node-3 --net host --privileged=true -v /www/server/redis_master_slave/master_slave3/master:/data redis:latest --cluster-enabled yes --appendonly yes --port 6383

docker run -d --name=redis-node-4 --net host --privileged=true -v /www/server/redis_master_slave/master_slave1/slave:/data redis:latest --cluster-enabled yes --appendonly yes --port 6384

docker run -d --name=redis-node-5 --net host --privileged=true -v /www/server/redis_master_slave/master_slave2/slave:/data redis:latest --cluster-enabled yes --appendonly yes --port 6385

docker run -d --name=redis-node-6 --net host --privileged=true -v /www/server/redis_master_slave/master_slave3/slave:/data redis:latest --cluster-enabled yes --appendonly yes --port 6386


// The second step ： Enter any one redis Inside the host container ： For each master Create a slave From the node 
docker exec -it redis-node-1 /bin/bash

// Input yes
redis-cli --cluster create 192.168.19.107:6381 192.168.19.107:6382 192.168.19.107:6383 192.168.19.107:6384 192.168.19.107:6385 192.168.19.107:6386 --cluster-replicas 1


// The third step ： Through one Redis host （ Non slave ）, View the entire Redis State of the cluster  ==  The container I am currently entering is the host 
redis-cli -p 6381
cluster info 
cluster nodes


// According to the above figure cluster nodes Information about , here Redis The master-slave relationship allocated by the system is ： Lord 6381->  from 6385、 Lord 6382->  from 6386、 Lord 6383->  from 6384


// Step four ： test reids Storage ： Find out key1、key4 There are errors in setting , because key1、key4 The hash value of belongs to other slots , That is, other hosts, such as hosts 6382、6383 Before you can save 
// If you need to report no error in the current host , Automatically put key1、key4 Save to other machines , Get into redis The client uses the cluster mode ：redis-cli -p 6381 -c
set key1 value1
set key2 value2
set key3 value3
set key4 value4
exit

// Step five ：redis client   Optimize route jump  ==  Every time I run set、 Pay attention to the change of port number 
redis-cli -c -p 6381
set key1 value1
set key2 value2
set key3 value3
set key4 value4
exit

// Step six ： View cluster information （ Another order ）cluster node  You can also see the cluster information 
// Look at all of... In the cluster key Distribution of hosts , And master-slave relationship 
redis-cli --cluster check 192.168.19.107:6381


// Step seven ： Simulate the downtime of one of the hosts （ I take 6381 Host downtime is a test ）, Check the corresponding slave 6385 Whether it can automatically become a host , Carry out leveling 
exit
exit
docker stop redis-node-1
docker ps
docker exec -it redis-node-2 /bin/bash
redis-cli -c -p 6382

//  Step eight ： The original host can be observed 6381 Slave of 6385 Automatic level replacement into host 
cluster nodes


// Step nine ： Re 6381 Get up , Observe 6381 Whether it will change back to the host ,6385 Become a slave 
exit
exit
docker start redis-node-1
docker exec -it redis-node-2 /bin/bash
redis-cli -c -p 6382
// Step 10 ： It can be observed that  6385 Will not come back because of the old leader 6381 It will be reduced to slave 
cluster nodes


// Step 11 ： Adjust architecture , take 6381 Become a host  6385 Become a slave 
exit
exit
docker stop redis-node-5
// etc. 1 Minutes in the morning 
docker start redis-node-5
docker exec -it redis-node-2 /bin/bash
redis-cli -c -p 6382
// The twelfth step ： It can be observed that  6381 Become a host ,6385 Become a slave 
cluster nodes

//==================== Capacity expansion starts ==============================================
// Thirteenth Step ： Ready to expand , Add two machines , host 6387、 Slave 6388 Enter the cluster 
exit
exit

docker run -d --name=redis-node-7 --net host --privileged=true -v /www/server/redis_master_slave/master_slave4/master:/data redis:latest --cluster-enabled yes --appendonly yes --port 6387

docker run -d --name=redis-node-8 --net host --privileged=true -v /www/server/redis_master_slave/master_slave4/slave:/data redis:latest --cluster-enabled yes --appendonly yes --port 6388

docker ps

// The fourteenth step ： Get into redis-node7 Containers 
docker exec -it redis-node-7 /bin/bash

// The fifteenth step ： Add current redis Machine entry master colony 
redis-cli --cluster add-node 192.168.19.107:6387 192.168.19.107:6381

// Check the cluster  ==  Discover new 6387 The host has no slot 
redis-cli --cluster check 192.168.19.107:6381

// The sixteenth step ： Order the entire cluster to reallocate slots , Make the new host 6387 There are also slots 
// How to divide ：16384/4=4096  fill 4096 go in 
// To whom ：6387 Mechanical Redis Defined ID identifier ： fill ad03db99f539b78b0b57c37c529f9eb2f612bb18
// The whole plane ： New configuration ： fill all
// Assigned starting ：yes
redis-cli --cluster reshard 192.168.19.107:6381

// The seventeenth step ： Check the cluster  ==  Discover new 6387 The host has slots （ The original three slots , Everyone agreed to come over a little ） ==  And will cluster all key All reassigned 
redis-cli --cluster check 192.168.19.107:6381

// The eighteenth step ： take 6388 The assignment becomes 6387 Slave of 
// Delete node command ：redis-cli --cluster del-node  node IP: Node port number   Node identifier 
redis-cli --cluster add-node 192.168.19.107:6388 192.168.19.107:6387 --cluster-slave --cluster-master-id ad03db99f539b78b0b57c37c529f9eb2f612bb18

// The nineteenth step ： Check the cluster  ==  see 6387、6388 Whether it is a master-slave relationship 
redis-cli --cluster check 192.168.19.107:6381

//==================== The expansion is over ==============================================


//==================== Shrinkage start - Delete the slave node first 6388, Slot reallocation , Delete the master node 6387, Return to 3 Lord 3 from ====
// The twentieth step ： Delete from node 6388
redis-cli --cluster del-node  192.168.19.107:6388 dc89a64b98290f4164e4ba1b6e8841a8b9d8d763

// Step 21 ： Check the cluster  ==  View slave nodes 6388 Removed from cluster 
redis-cli --cluster check 192.168.19.107:6381

// Step 22 ： Start reallocating slots 
// Number of slots allocated ：4096
// Who receives the assigned slot ：6381 Node ID identifier   fill ：2d8bb525e25ecb239dbe059f8545eda64182e514
// Who assigns slots ：6387 Node ID identifier   fill ：ad03db99f539b78b0b57c37c529f9eb2f612bb18
//done
redis-cli --cluster reshard 192.168.19.107:6381

// Step 23 ： Check the cluster  =  so 6387 Of key All allocated to 6381
redis-cli --cluster check 192.168.19.107:6381

// Step 24 ： Delete from node 6388
redis-cli --cluster del-node  192.168.19.107:6387 ad03db99f539b78b0b57c37c529f9eb2f612bb18

// Step 25 ： Check the cluster  ==  Look at the master node 6387 Removed from cluster 
redis-cli --cluster check 192.168.19.107:6381

//==================== End of volume reduction ==============================================

The whole construction process