I maintain a ES cluster which has 16 nodes.
(3 master, 11 data, 2 clients)
My question is that which sequence do I need to do a rolling upgrade among 3 types of node.
I'm supposed to upgrade data nodes first and client nodes and finally master nodes.
I guess if I upgrade master nodes first, my cluster would be changed to 5.6 cluster
as a result, I think it would be hard to connect 5.5 data nodes into 5.6 master.
So I want to verity that wheather I need a sequence to do a rolling upgrade or not.
Thanks you every time for a smart answers.
P.S. I also want to apply x-pack plugin BTW, does it make sense to conform the same sequence as I do a rolling upgrade?