In your integration documentation, you make reference to several PHP variables - can you tell me more about them?

When you are setting up your PHP/FCGI runners, its important to configure the correct variables for your environment. However, first you need to understand what these variables we refer to in our integration instructions.

PHP_FCGI_CHILDREN="8"

This value relates to the number of php.fcgi processes you wish to be spawned. When considering this number, we would recommend our default of 8 initially, then start your in-house benchmarks to assertain whether or not your server could benefit from more children processes being spawned.

Please remember, you will almost certainly see your CPU usage rise as you add more children. Adding additional children results in, theoretically, being able to handle more simultaneous connections at a time (but please bear in mind that if all child processes are busy, then connections will wait around rather than failing) - but will also cause CPU utilisation to rise (through the extra burden of additional context switches, if nothing else).

PHP_FCGI_MAX_REQUESTS="500"

PHP has been known for its memory leak problems. To counter this you are able to limit the total number of requests that a single child process is able to handle before it kills itself.
This leads to some overhead being required to start the new process - but ensures that, if there are any memory leaks, they can't become significant enough to become problematic.

Content Manager [Administrator] 20 April 2006