See the following to familiarize yourself with concepts and terminology related to user sessions in Dynatrace.
A user session summarizes user events for one end user within a limited timeframe. It records timings and aggregates key counts and errors for fast analysis.
In Dynatrace, sessions are represented in two record types:
Granular user events—for interactions, navigations, requests, errors, and more.
A session summary event—consolidates a session start time, end time, duration, end reason, counts, errors, identifiers, and context data.
A user session includes:
Technical events such as requests, errors, and navigations.
User interactions such as clicks, taps, scrolls, keypresses, and more.
The user interactions are a part of Experience Analytics. They're currently available in preview to all users free of charge.
A session summary records the start time of the first event in a session, and the end time of the last event in the session, to calculate the overall session duration.
Each user event includes dt.rum.session.id to identify the session.
A RUM module instance (the frontend module) running on the user’s device is identified by dt.rum.instance.id.
After a session ends (or is discarded), the JavaScript module might still capture events with the same dt.rum.session.id—they remain available at the event level but aren’t included in any session summary.
A user session summary consolidates key information for filtering and segmentation:
Timing and reason: start_time, end_time, duration, and end_reason.
Event counts: navigation_count, page_summary_count, request_count, user_interaction_count, and view_summary_count.
Error tallies: error.count, error.http_4xx_count, error.http_5xx_count, error.anr_count, error.csp_violation_count, and error.has_crash.
Characteristics: characteristics.has_replay and characteristics.is_invalid.
Identifiers and user context: dt.rum.session.id, dt.rum.instance.id, dt.rum.user_tag, and related application entity references.
Platform context: a browser (name, version, window size), OS (name, version), device (manufacturer, model, screen, type), geolocation (a country ISO code), and client network details (IP, ISP), as available per technology.
Session properties: session_properties.__property_name__ for custom key-value enrichment configured in your environment.
You can filter sessions using aggregated attributes (for example, error counts or request volume) to prioritize investigations.
You can drill into correlated events via dt.rum.session.id to explain session-level findings with detailed evidence.
Links to semantic dictionaries: