Questions about the configuration of agent-analyzer

[linshenfanying]

Questions about the configuration of agent-analyzer:

1. In the trace-sampling-policy-settings.yml file, I have configured the sampling rate for Service A to be only 10%.
2. forceSampleErrorSegment is set to true.
   My question is: Will error traces in Service A be captured at a 100% rate?

[wu-sheng]

Yes, that is the meaning of force sampling.

[wu-sheng]

As an upstream of A(error occurred), service B has nothing related to this sampling policy.
If you don't propagate error back, meaning if oap can't see an error flag from the trace segments of B, B is following its own sampling rate.

[linshenfanying]

Does this mean that if an error in service A is propagated back to service B, then service B will also be forced to record this trace? If the error in service A is not propagated back to service B, and service B’s sampling rate does not sample this trace, will this trace be lost?

[wu-sheng]

The part of downstream could be dropped if not sampled according yo your rate.

[linshenfanying]

1. If the sampling rate of each service is the same, can it ensure that the downstream can also collect (the trace)?
2. Regarding the sampling rate implemented by the OAP server, does the Java Agent report all data, and then the OAP Server implements sampling rate control during processing?

[wu-sheng]

1. If the sampling rate of each service is the same, can it ensure that the downstream can also collect (the trace)?

No, it can't. There is no logic relationship.

2. Regarding the sampling rate implemented by the OAP server, does the Java Agent report all data, and then the OAP Server implements sampling rate control during processing?

Yes, it is.

[linshenfanying]

Here are a few other questions. Could you help me answer them?

1. Regarding the slowDBAccessThreshold configuration item, if I set it, will any database access that exceeds the threshold be recorded regardless of the service's sampling rate? And is the recording method the same as that of forceSampleErrorSegment?
2. What's the specific function of the segmentStatusAnalysisStrategy configuration item?

[wu-sheng]

Can't provide that for now, I am on vacation, don't have codes and laptop on my hands.

[linshenfanying]

Any progress on this yet?

[wu-sheng]

No, I will be back until 27th.