I have a 3 node cluster in the following setup:-
2 x nodes running percona-xtradb-cluster-server-5.6 5.6.30-25.16-1.wheezy
1 x node percona-xtradb-cluster-garbd-3.x (arbitrator voting member).
I am looking to migrate the cluster onto Debian Jessie, but also upgrade to Percona 5.7.
As this is a live cluster, I am very reluctant to upgrade the existing cluster nodes (and ultimately want to avoid as much downtime as possible).
My question is, can I join a node running Percona 5.7 into the existing cluster running Percona 5.6? I.e, build 2 new nodes running Percona 5.7, add them into the cluster, let them sync, then remove the nodes running 5.6…
Any help will be greatly appreciated.