An event is a collection of runtime-related information collected by the Zend Server Monitor component. This information is collected when an event is triggered, according to the conditions defined by the Event Rules. An event indicates that your environment is displaying uncharacteristic behavior and that something occurred that exceeded your definitions and the standards of how you want your PHP code to run. Each individual event includes specific information about the occurrence, such as when it happened, how many times it happened and other details that can assist a developer in diagnosing the event.
Events are only created when the Zend Monitor component is running.
If events are triggered by the same rule and have similar characteristics – e.g., filename, URL, line, etc. – they are aggregated into a single issue. If they do not have similar characteristics, a separate (new) issue is created.
Inside a single issue, events are divided into groups according to when they occurred. A new group is created only if there is no activity for at least five minutes. If a new event occurs after five minutes pass, a new group is added to the issue. The new group includes all the events that occurred, as long as five minutes without activity have passed.
Each event is different and therefore the information collected and displayed for each event may differ. For example, a Slow Request event does not include information on a source file or line of code, because the event was generated by a request. The same is true for Java backtrace information: Java backtrace information is only included for Java exception events.
The first layer of issue details are the basic details. These details are used to identify an issue with high-level characteristics. These characteristics are displayed in the Events list on the Events page. These details are useful for performing an initial assessment of the event and prescribing the right resources for dealing with it.
Each issue is an aggregation of one or more events with common, predefined characteristics. These common characteristics are displayed in the Summary area on the Event Details page. Therefore, you can assume that each event that occurred for this issue has at least these details in common. This is the first step in identifying the source of the event and understanding the circumstances surrounding the event.
Grouping is yet another additional aggregation layer applied to an issue. Inside a single issue, events are divided into groups according to the time they occurred. A new group is created only if there was no activity for at least five minutes. If a new event occurs after five minutes have passed, a new group is added to the issue. The event details for these groups are displayed in the Event Details table on the Event Details page.