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Application Real-Time Monitoring Service:Why are traces missing?

Last Updated:Mar 11, 2026

ARMS samples trace data to balance storage costs against observability. Sampling reduces the volume of stored traces while preserving visibility into errors and anomalies. By default, not every request produces a stored trace, which is why only a small number of traces may be generated even after you initiate multiple requests.

Cause

The default sampling rate is 10% -- only 1 in 10 requests generates a stored trace.

Certain trace types bypass the sampling rate and are always collected:

Trace typeARMS agents V3.xARMS agents V4.x
Error callsAlways collectedAlways collected
Abnormal callsNot collectedAlways collected
Slow callsNot collectedNot collected

Solution

Increase the sampling rate in the ARMS console:

  1. Open the Configuration page for your application.

  2. Click the Custom Configurations tab.

  3. In the Sampling Settings section, increase the sampling rate to capture a higher percentage of traces.

Sampling Settings in the ARMS console