Long task user events capture tasks that block the browser's main thread for an extended period, impacting user experience and performance.
Long task
A long task is a browser task that occupies the main UI thread long enough to cause high or variable input latency and prevent users from interacting with the page. Long tasks are detected using the W3C Long Tasks API. Dynatrace RUM captures long tasks as individual user events and also aggregates them within page summary and view summary events. Only supported by RUM JavaScript.
Query
This query searches for all long tasks.
fetch user.events
|filter characteristics.has_long_task == true
Long task characteristics fields
Attribute
Type
Description
Examples
characteristics.classifier
string
experimental Fixed value other.
other
characteristics.has_long_task
boolean
stable Fixed value true.
true
Long task fields
Attribute
Type
Description
Examples
long_task.name
string
stable One of the following strings refers to the browsing context or frame that can be attributed to the long task: cross-origin-ancestor, cross-origin-descendant, cross-origin-unreachable, multiple-contexts, same-origin-ancestor, same-origin-descendant, same-origin, self, unknown.
cross-origin-ancestor
long_task.attribution.container_id
string
stable The ID of the container where the long task happened.
app-iframe
long_task.attribution.container_name
string
stable The name of the container where the long task happened.
app-iframe
long_task.attribution.container_src
string
stable The source of the container where the long task happened.
http://www.dynatrace.com
long_task.attribution.container_type
string
stable The type of container where the long task happened.