on - edited on by
Adam-Piotrowicz
- Problem
- RUM JavaScript isn't injected
- RUM JavaScript isn't downloadable
- RUM JavaScript doesn't report data to server
- What's Next?
Problem
This page explains what to do when Real User Monitoring (RUM) isn't working in your environment, specifically when there are issues with the bf.
Responses should have the 200 OK status, and the response body should start with OK. If the response body starts with FL, the RUM beacon was rejected and not forwarded to the server. The response contains additional information about the problem. For further details, check RUM JavaScript doesn't report data to server.
RUM JavaScript isn't injected
If you don't see the RUM JavaScript automatically injected by OneAgent into your webpages, it's probably because of one of the following reasons.
- Dynatrace OneAgent could not identify the content as HTML or canceled the injection attempt due to an invalid HTML structure or incorrect encodings. Make sure that you're using well-formed HTML with opening and closing tags for <HTML> and <HEAD>. See RUM JavaScript injection to learn how OneAgent injects the RUM JavaScript into your application.
- The request maps to a different application than expected because application detection was set up incorrectly. Either the pattern is incorrect, or the associated web servers operate behind proxies or other components that are rewriting the URL. For details, see What can I do if an uninstrumented component rewrites parts of the URL?.
- The application that is detected by OneAgent on the first instrumented tier is not propagated to subsequent OneAgents because the x-dynatrace-application header is removed by a firewall or proxy.
- You have defined exclusion rules for browsers, robots, and spiders.
RUM JavaScript isn't downloadable
If you see that the RUM JavaScript isn't downloadable, there might be a few reasons for that.
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For agentless monitoring
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The RUM JavaScript is incorrect. Verify setup with Set up agentless Real User Monitoring documentation.
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Content Security Policy rules prevent loading of the RUM JavaScript.
- The RUM JavaScript host https://js-cdn.dynatrace.com isn't reachable for client browsers due to firewall rules or proxy server configuration. Connections to and from the host must be allowed.
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For automatic injection on web servers
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Rules on firewalls, load balancers, or proxies aren't configured to allow RUM JavaScript download. Refer to Firewall constraints for RUM for details.
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For automatic injection on Java application servers
- Root application doesn't exist. The RUM JavaScript is usually loaded from the web server root path (.../ruxitagentjs_...).
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Your Java application server serves static content in a way that doesn't use the servlet stack. In such cases, the RUM JavaScript can't be downloaded.
To resolve a JavaScript download issue caused by a missing root application, configure an accessible path (for example, a valid servlet path) as described in Modify the monitoring code URL path.
RUM JavaScript doesn't report data to server
If you see that the RUM beacons are rejected and not forwarded to the server, there might be several reasons for that.
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Rules on firewalls, load balancers, or proxies may need to be adapted. Refer to Firewall constraints for RUM for details.
- Beacons may fail if their auto-selected URL path is blocked, but you can fix this by adjusting the URL before the
rb_prefix. Read more here. - Dynatrace throttled the capture rate of your application.
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Content Security Policy settings may need to be adapted.
What's Next?
If you continue to see the unexpected behavior after completing all the troubleshooting above, please contact Dynatrace on the in-product chat/ create ticket. Provide the following information:
- Link to the RUM application in Dynatrace,
- Link to the related Service(s) or Process Group(s) in Dynatrace,
- State the issue and the troubleshooting that you have completed,
- Link to the application being monitored with steps to reproduce the issue.
- If the application is not publicly available, provide a har file.
