Surprised that Enablement and Cost control does not apply a ratio on captured trafic

[Aymeric_M]

Is that a recent bug ? 

In order to reduce cost we applied a global 20% limit on all web application session capture.

In order to investigate user issues we enabled 100% capture on one web application.

I was surprised to see that Dynatrace was reporting trafic increase the exact moment we switched to 100% capture and instant trafic decrease when we switched back to 20%.

Today we got "Unexpected low trafic" alerts on that web app, but trafic is normal compared to the same period on the last 30 days. Except for when we switched to 100% capture and Dynatrace falsely show 5 times more user actions per minute.

[Julius_Loman · Accepted solution]

Unexpected low traffic works with absolute numbers of user actions (captured ones) and does not consider cost control. 

[tomaxp]

Hi,
This is not a bug – this is expected behavior.
The "Enablement and Cost Control" setting only limits how many sessions are actually captured and stored, but Dynatrace still calculates metrics and anomalies based on the number of captured user actions.

So when you switch from 20% to 100% capture, Dynatrace immediately sees up to 5x more captured actions and adjusts its baseline accordingly. When you switch back to 20%, the sudden drop looks like "unexpected low traffic" compared to the newly learned baseline.

If you frequently switch capture rate for diagnostic purposes, you may want to temporarily disable "Unexpected low traffic" anomaly detection for this application, or keep the capture rate consistent to avoid baseline shifts.