JavaScript Long Task Monitoring
Feature
Germain UX RUM JS captures JavaScript tasks that occupy the UI main thread for 3 seconds or more. Usually that blocking and uninterrupted task causes:
delayed time to interactive (TTI)
high input and event handling latecy
bad animations and scrolling
By default, this monitoring is enabled for each User Monitoring Profile.
KPIs
KPIs for User Monitoring and Replay | JavaScript-Long-Task-Monitoring-KPIs
Example

JS Long Tasks on Drill-through

JS Long Tasks on Session Replay
Configuration
Threshold
You can update long task threshold by setting settings.plugins.performance.longtaskThresholdMillis
in the Init Script.
The following code sample shows how to collect long tasks only if equal or longer than five seconds.
const settings = germainApm.getDefaultSettings();
...
settings.plugins.performance.longtaskThresholdMillis = 5000; // in milliseconds
...
germainApm.start(settings);
Component: RUM JS
Feature Availability: 2022.2 or later
Browser Support: only latest Chrome, Edge and Opera