Odd issue with "session" table

[MarkFL]

I provide technical assistance at a forum running vB 4.2.2, and a few days ago for no apparent reason the "session" table began to fill up and throw a MySQL error preventing our users from using the site.

I directed the site owner to truncate the "session" table via phpMyAdmin, and we were back up. However, the issue came back very soon.

The first thing I checked was to make certain the cronimage was intact in all of the footer templates, which it is, and I verified the image is present in the DOM of all the styles.

Next I checked the Scheduled Tasks, and verified that the 2 hourly cleanup tasks are being run. One was set at 5 after the hour and the other at 20 after, and I changed to one set at 20 after to 35 after so that the two hourly cleanups would be 30 minutes apart. The issue persisted.

As a temporary fix, I wrote a plugin that prunes the "session" table of all expired rows any time one of the 4 senior staff members loads the index, showthread, search and online scripts. When I leave my compute for more than a few minutes I leave Who's Online running so it will auto-refresh and keep pruning the table.

Earlier today, I followed:

AdminCP -> Maintenace -> Diagnostics -> System Information -> Table Status

and I found that the "session" table has very small values for Data_length and Max_data_length:

Data_length: 11744
Max_data_length: 12768

At MHB (Math Help Boards) these values are:

Data_length: 127296
Max_data_length: 13486755

And on my local dev site, they are:

Data_length: 129500
Max_data_length: 14738963

So my questions are:

• Is it possible that these values were recently changed (via plugin code or host) to be much smaller?
• How do we go about resetting them to larger values?

I appreciate any advice you can give.