In Dynatrace SaaS, how can we tell which nodejs servers are actively instrumented with RUM?

[anthony_percy2]

We have a openshift based system that uses about 40 "micro" web servers with openshift-router controlling the "http routing". We can see that a "ruxit" url in the browser but how can we tell which micro webserver it comes from? We have tried looking in the log files to no avail. Dynatrace does indicate the docker container/pod that is showing certail urls but there does not appear to be any confirmation of the RUM injection in the log files.. Can a "RUM injection" log be turned on for example?

Regards

Anthony

[AlexanderSommer · Accepted solution]

By default every instance which is monitored with a Dynatrace OneAgent will do RUM injection and RUM beacon handling. The RUM GET and POST you are referring are for downloading the RUM JS file and the POST is the beacon which is send back from the browser.

RUM JS injection and beacon handling can be turned off at process level if needed.

[anthony_percy2]

Thanks Alex, we are seeing the GET and POST fine and even with a type=check but no user sessions are seen... Look like we are back to curl...

[Julius_Loman · Accepted solution]

AFAIK you can't. You can turn off/on RUM instrumentation at different levels.
On "Application" level - (you can even have special rules for particular pages) then the rules for injection get pushed to Oneagents.
On "Process group" level as @Alexander S. suggests, this will turn off/on injection for all applications served by services in all processes in the process group.

The most accurate answer will be to loop through every nodejs server for every application with some curl GET/POST (don't forget to set User-Agent to a real browser) and look for the JavaScript file. There can be several reasons why RUM JS will not get injected even if everything is setup correctly in Dynatrace (proxy / firewall / non-standard application / ... )

[anthony_percy2]

Thanks Julius, I just thought there may be a debug option that would let use see what RUM was actually doing on nodejs...

[Julius_Loman]

Some information can be seen in the Oneagent logs (rules for injecting). But this actually does not imply RUM JS will be injected for particular request. More information can be seen if debug flags for RUM are enabled. However they must be set by Dynatrace support. I'm not aware of any debug settings exposed in SaaS or Managed.

[anthony_percy2]

Thanks Julius for the comment., It would be great if Dynatrace would make available documentation that has info about how to turn debugging on for the OneAgent.. It would certainly reduce the amount of support calls we would have to make when the automated installation fails in some way and at least give us a chance to troubleshoot before we have to contact support...:-(