This is a performance-monitoring event.
(Absolute - a customer configured hard number; Relative - a customer configured percentage)
Excess Memory Usage events identify when scripts are using excess memory that can hinder the application's ability to perform.
Production environments mainly use this event type but QA can also benefit from monitoring by KB or percentage of memory used by a script to execute.
Excess Memory Usage (Absolute) - Generates an event when memory for PHP script execution uses more than a set amount of KB for moderate events and severe events.
Excess Memory Usage (Relative) - Generates an event when memory use for PHP script execution is above or below average, a set percent for moderate and severe events.
Both Event Types are only active if the PHP is compiled with memory limit. (Compile the PHP, with the configure switch "--enable-memory-limit".
The default values for both of these event types are set to 0. To generate events, configure these settings to a value that suits required memory usage.
Event definitions are based on relative values i.e. percentage. Relative values are set according to warm-up settings, default value of 500 requests. If necessary, modify the default value by changing the zend_monitor.warmup_requests directive in the 'zend.ini'.