We are having a huge problem with Magento 184.108.40.206 performance after a server upgrade on the same host because of a hardware issue.
We have a system like this: 1 server for Web, 1 server for DB and 1 server for redis (session only)
Servers are really big (16 cores, 64GB RAMs ... etc), the connection between the servers is by private IP for better performance but with all that suddenly after this upgrade and a maintenance down time something happened and the whole system is running really bad: load time, running exports ... etc and from time to time not loading at all (like once a day).
We've checked everything, and tried to disable a lot of modules but with all that we still don't know what's happening.
Any input on how to debug this or start understanding the issue is much appreciated
No, they said everything is fine and indeed i put WP for couple of minutes to see how it works and there's no issue there so for sure something happened within Magento system.
I'm thinking that some component, PHP ext ... etc changed on the upgrade and now magento is really slow because of that.
At the same time i feel that all this issue has something to do with the cache ( not the session ) but the rest, any ideas how could i debug some major issues and common issues on this side ?