Based on percona update procedure (https://www.percona.com/doc/percona-server/5.7/upgrading_guide_56_57.html) you need to do :
sudo service mysql stop
sudo apt-get install percona-server-server-5.7
sudo service mysql restart
In my case I have a cluster with 3 nodes (multi-master):
My questions are :
- Do I need to run mysql_upgrade on all nodes or only on first one upgraded ?
- Is there any problem if until I complete update on all nodes some of them will run 5.6 and some 5.7 ?