Online migration of redis clusters
Migration scenario steps
Deploy the new node redis instance. (note that after deployment, there is no need to create a cluster.)
For example:
Old environment:
192.168.3.5:7000 M
192.168.3.5:7001 M
192.168.3.5:7002 M
192.168.3.5:7003 S
192.168.3.5:7004 S
192.168.3.5:7005 S
New environment:
192.168.3.6:7000 M
192.168.3.6:7001 M
192.168.3.6:7002 M
192.168.3.6:7003 S
192.168.3.6:7004 S
192.168.3.6:7005 S
Add the new node redis to the old cluster. (add master node)
Redis-trib.rb add-node 192.168.3.6:7000 192.168.3.5:7000
Redis-trib.rb add-node 192.168.3.6:7001 192.168.3.5:7000
Redis-trib.rb add-node 192.168.3.6:7002 192.168.3.5:7000
Add the new node redis to the old cluster. (add slave node)
Redis-trib.rb add-node-- slave 192.168.3.6 Virgo 7003 192.168.3.6 Vol 7000
Redis-trib.rb add-node-- slave 192.168.3.6VR 7004 192.168.3.6RV 7001
Redis-trib.rb add-node-- slave 192.168.3.6Rose 7005 192.168.3.6VOL7002
Check the cluster master-slave node information
Redis-cli-p 7000-a 'password' cluster nodes
Check whether the cluster status () is ok
Redis-cli-p 7000-a 'password' cluster nodes
View redis cluster master nodes
Redis-cli-p 7000-a 'password' cluster nodes | grep master
View cluster information
. / redis-trib.rb info 192.168.3.5:7000
Cluster for migration
. / redis-trib.rb reshard 192.168.3.5:7000
Note: migrate all slot to a new cluster master node.
Input: all
Enter slot: 16384
Migrate to node_id: 614272e21df1cbbcda117f277ff7baa075b3d15e (new node migrated id)
Evenly slice the slot to the new remaining master node
. / redis-trib.rb reshard 192.168.3.5:7000
. / redis-trib.rb reshard 192.168.3.5:7001
. / redis-trib.rb reshard 192.168.3.5:7002
Check whether the node migration is normal
/ redis-trib.rb echek 192.168.3.5:7000
Delete old node information (delete slave node first, then delete master node)
Delete slave node
/ redis-trib.rb del-node 192.168.3.5:7000 3c0bb15b23407f7eb6f8c5a6a2a4c9ffb7065098
/ redis-trib.rb del-node 192.168.3.5:7001 32afb3fec4ecad4bd33573a45754616324a9311b
/ redis-trib.rb del-node 192.168.3.5:7002 5f2018a5a56f3e4cfc76df566e721ca7ace8bd83
Delete the primary node (ibid.)
Note: the old environment after del-node redis process shutdown, cluster failure!
Check cluster availability and data integrity
/ redis-trib.rb check 192.168.3.5:7000
/ redis-trib.rb info 192.168.3.5:7000
Redis-cli-p 7000-a 'password' cluster nodes
Redis-cli-p 7000-a 'password' cluster info
The test works well!
