Online visitors count gets restarted!

[quitsmoking]

I have a weird problem which is that between 22:00 and 01:00, the number of online visitors gets restarted like twice. It stays around 2000 but suddenly I get kicked out of the admin area and the online counter starts over from zero!

Any idea what the possible reasons could be? There are no mysql or apache error logs during this period at all.

Thank you.

[ssslippy]

Would you happen to have a repair or optimize tables running on cron?

[geevest.com]

quitsmoking ur problem like me :)
u can check my thread in general vbulletin discuss.

hope u can fixed ur issue.

[quitsmoking]

Would you happen to have a repair or optimize tables running on cron?
Yes I did. And this did not stop the problem.

@geevest.com: I am at liquidweb too :)

[Dismounted]

MySQL could have been restarted, which would have dumped the session database. Check the MySQL uptime.

[quitsmoking]

mysql was not restarted. The uptime shows the same uptime of the server!
Thank you.

--------------- Added 1213864283 at 1213864283 ---------------

I investigated for a while and I found that the type of these tables:
session
cpsession
is different from the other tables. They are HEAP (MEMORY) so that they run faster. What could be happening to them or their files? I need a mysql guru I guess.

[Marco van Herwaarden]

As stated before, HEAP (in memory tables) are emptied when MySQL is restarted.

[quitsmoking]

OK but since mysql uptime is not different from the server's, then mysql was not restarted. In fact, I investigated even more and I found that there is a reported bug that could be the same as my situation:
http://bugs.mysql.com/bug.php?id=19138

Therefore, I asked my server's company to upgrade mysql. I will see if it solves the problem and update you.