OpenTelemetry on Layer7 API Gateway 11.1

[Thianrawit Teevasupitikasem]

We enabled opentelemetry in our environment, and the problem is that we can't see some traces in our monitoring tools. We observe that the problem relates to one parameter call 'trace_flags'. We don't see this parameter in layer7, but we found 'trace_flags' parameter in another application logs we called. When 'trace_flags' is '00' the traces are missing. If it is '01' the traces are exist. And layer7 is the first one who start Opentelemetry traces. This behavior is like trace sampling. So we have questions on below
 
1. Does Layer7 enable Opentelemetry Traces sampling by default?
2. If it enable traces sampling, can we change this parameter? how to?
3. If we would like to recheck 'trace_flags' parameter in layer7 logs, how to do that?

[Ben Urbanski]

Hello, Thianrawit.

The gateway allows you to configure which services will be traced per this documentation using the otel.traceConfig cluster-wide property. We refer to this configuration as filtering, and when your filter selects a service to trace than all transactions for that service will generate a trace that will be sent to the collector. In other words, the gateway does not do sampling. Collectors can be configured to sample, and many do sample by default. This is controlled by your collector configuration, not the gateway. The gateway does not support a "trace_flags" parameter.

Regards,

Note, the 

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Ben Urbanski
Product Manager, API Gateway
Layer7 API Management
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