Manual:$wgJobRunRate

Details
The job queue is designed to hold many short tasks. By default, each time a request runs, one job is taken from the job queue and executed. If the performance burden of this is too great, you can reduce $wgJobRunRate by putting something like this in your LocalSettings.php:


 * $wgJobRunRate = 0.01;

This probably means, the normal setting is = 1.00, so every time a user sends a request to the wiki, on task of the job queue will also be executed. On heavy load wikis it might be better to do it every 100 times, so i figure that is what is meant above.

You can view the length of the job queue by visiting Special:Statistics on most 1.6 wikis.

The job queue is located in Wiki.php (function doJobs).