o11y - "Trace not found" from linked APM traces in Synthetics Tests

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Updated:September 29, 2026
Document ID:SPLK047703

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Applicability

Splunk Synthetics Monitoring

Description

There is an option to link Synthetic spans to APM spans, to follow the story of data from front-end to back-end.

However, it could happen that in some tests, when clicking on APM link icon, it results with “Trace not found” info:

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Investigation

  • First, check if APM link appears next to the span in the waterfall view of run results page:

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  • then, expand one of these spans and validate that server-timing header is present:

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Resolution

To fix:

  • If the required header is present but  "trace not found" error is still displayed
    • check the token used by the application to send spans to Splunk APM.
    • This issue can occur if APM trace data is being sent with an expired token, causing it to be dropped.
      • Meanwhile, Synthetics data might still be accepted if it’s sent using a valid token.
    • Once the token gets updated to a valid one, the links begin to work.

Link Synthetic spans to apm spans

Revision History

Revision Publish Date Comments
1.0
29-Sep-2026
Initial Release

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