topic Re: usersession.userId missing in NEW RUM in Real User Monitoring

usersession.userId missing in NEW RUM

GregOReilly — Mon, 27 Apr 2026 11:08:52 GMT

Is the real user monitoring move to Grail complete?

When I run a query in the classic session segmentation/query I want to group by usersession.userId.

However, in the new RUM app (users and sessions, experience vitals) and DQL Query, I cannot see this metric. The RAW Event data some session related ID fields, but the values are not the same as above. (dt.rum.session.id for example).

Re: usersession.userId missing in NEW RUM

t_pawlak — Sat, 14 Mar 2026 20:55:16 GMT

Hi,
As far as I know, the RUM move to Grail is not fully complete yet. The New RUM Experience is already on Grail, but Dynatrace still depends on some RUM Classic functionality, so a full cutover is not yet possible.
About your specific field:

usersession.userId in Classic/USQL is the user ID provided through user tagging. In practice, this is the meaningful custom user identifier set for example via identifyUser or page metadata. Tag specific users for web applications
dt.rum.session.id in Grail is just the session ID.
dt.rum.instance.id in Grail maps to the internal user ID / visitor ID / rxVisitor cookie value, not to your Classic usersession.userId.

So your observation is correct: these values are not expected to match.

If you need the same kind of identifier in DQL, the practical approach is to capture it explicitly as a session property in the New RUM Experience and then query it from user.sessions.

You can also check the documentation here: Transition from RUM Classic to the New RUM Experience

Re: usersession.userId missing in NEW RUM

Cindywei — Fri, 10 Apr 2026 07:27:36 GMT

Hi Guys,

May I know whether the migration of RUM to Grail is completed or not?

We've encountered similar issue which monitoring data missing in the new RUM.