Introduced in LiteSpeed Web Server 4.2.13, the LSPHP_MaxWaitQ directive allows users to limit the maximum number of processes that can be in the PHP external application wait queue.
Placing a limit on the maximum number of processes in the wait queue is useful when PHP is overwhelmed. Processes that cannot be processed immediately are queued. As the queue gets longer, some of the processes in the queue will no longer be necessary (because the person accessing the site has closed their browser window, for example). It is thus better to turn away new processes before the queue gets too long, instead of trying to process requests from users that have already given up.
The external application wait queue can be found in your real-time statistics (WebAdmin console > Actions > Real-Time Stats).
LSPHP_MaxWaitQ is placed in an Apache configuration file. It can be used at the server or virtual host level.
Example:
<IfModule LiteSpeed> LSPHP_MaxWaitQ 25 </IfModule>
Note:
LSPHP_MaxWaitQ is a LiteSpeed-specific directive. Apache will not understand it and may crash if it is not wrapped in an <IfModule>
tag.