XF 1.4 5.5GB session table with growing pace 2MB+ per second

(The thread title was a direct quote from our system admin person.)

About 8 hours ago we announced something on the forum, and shortly after people started flooding in, we observed a dramatic growing speed of the session table size until it crashed the site with the following message:

An exception occurred: Connection refused in /www/sites/social.razerzone.com/public_html/library/Zend/Db/Adapter/Mysqli.php on line 333

Could anyone tell me how to fix this?

Also, the site is currently running on xlarge database.

Thank you!

Jake Bunce

XenForo moderator
Staff member
Expired sessions are pruned hourly by this cron:

Admin CP -> Tools -> Cron Entries -> Hourly Clean Up

Check the last run time to make sure it has been running. You can also manually run it.

5.5GB is ridiculous for the session records. I have seen situations where the cron fails to run for whatever reason which can result in a build-up of records, but it's still hard to imagine 5.5GB of session records.

Is this a legitimate volume of traffic based on your expectations? Or is it possible you are being DDoS'ed?

You should consult with your host about this surge of traffic which likely underlies that error message. If it's an attack then your host can address that on their end. If it's legitimate traffic then you may need to pay for more capacity.
Hi Jake,

We've found the reason - it's caused by one plugin installed to the forum. Disabled it and everything went back to normal.

Thank you very much!