What Are Events?
| Starting with PHP Extension 5.36.0 (March 2026), events are being migrated to become full-featured spans. The distinction between spans and span-events has been removed from the Timeline Profiler. |
Instrumented function calls that were previously stored as lightweight events—such as framework event listeners, view rendering, and lifecycle hooks—are now tracked as full spans. This means every instrumented operation provides the same level of detail:
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Timing and duration
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Memory allocation
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Custom annotation context
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Stack traces (when duration exceeds the configured threshold)
This migration covers events for Symfony, Laravel, Magento 2, Yii 1, Yii 2, WordPress, and PHPUnit test cases, among others.
Before the Migration
Previously, events were lightweight timespans occurring within a parent span, containing fewer details than regular spans. They appeared as small, light-blue spans beneath their parent and had no stack trace or annotation data.
After the migration, all instrumented operations are represented uniformly as full-featured spans, simplifying the Timeline UI and providing more insight into previously less visible operations.