members keep getting disconnected on 2 different vbulletin forums

[NeXuM]

I don't understand what's going on.

I have two vBulletin 3.6.4 forums on the same server (different domains and cookies, of course). Everything always worked good for over 5 years until a few days ago. Now, my members (including myself) keep getting disconnected when switching pages. We constantly have to reconnect only to get disconnected again a few minutes later.

The weirdest thing is that i haven't touched anything on these forums since a long time, which makes me think it could be a server issue.

I have a third vBulletin 3.6.4 forum hosted on the same server and this one *seems* to be fine. I haven't tested it heavily and this last forum isn't very active so i can't be 100% sure it isn't touched by the bug.

Any idea what can be the source of the problem ? It appeared by itself and i didn't touch anything...

[Zachery]

ARe you restarting MySQL constantly?

[NeXuM]

I think you're right, mysql was crashing very often since i had changed a setting to allow searches of 3 characters words. I reverted the change and it's better now.