Default Max Execution Time
PHP restricts how long any script can run through the
setting. By default this value is 30 seconds.
It is recommended to reduce this value for several reasons:
Several long running scripts at the same time can cause congestion, preventing other request sfrom users from being executed. These usually manifests in HTTP 503 errors from the webserver.
Great user experience is about quick response times, 30 seconds is far away from that. You can configure the
max_execution_timeto be higher for individual scripts at runtime, when its necessary. But for the general use-case in an application, the maximum execution time should be expected to be much lower.
It is also necessary to understand, that
max_execution_time is based on the
time spent executing the script, all I/O operations such as SQL queries, HTTP
requests or filesystem access do not count towards the execution time.
This means that
max_execution_time is not reliable way to restrict the time
spent running a script.