In this blog post I would like to give an overview of the most common failover scenarios and operations when using MySQL Group Replication 8.0.19 (aka GR) and Percona XtraDB Cluster 8 (PXC) (which is based on Galera), and explain how each technology handles each situation. I have created a three-node cluster with Group Replication using a single Primary and a three-node PXC, both with default settings. I am also going to use ProxySQL to interface with both clusters.
In both clusters, the name of the nodes are mysql1
,
mysql2
, and mysql3
. In Group
Replication the Primary node is where the writes go if we are
using single primary configuration. In PXC, I will use the same
term as well and will call the node Primary where I am sending
the writes. Just to note, in PXC there is no concept of primary
node, …