Common attributes

[shivchelwa]

Is there a way to set common attributes such as app-name, module-name etc. on all the spans that will be created in my library/application? I could not locate any such feature. Please let me know if there an API available.

Thanks

[jkwatson]

It sounds like you're looking for the Resource. You can set a Resource when configuring your SDK, and it can have any common attributes you might want, and also be supplemented from our resource auto-populators as well.

[shivchelwa]

@jkwatson, that explains the behavior. But, it restricts use case like this, where some end-users of an application may want to enable javaagent to get details from instrumented libraries(cassandra, http), others may choose to just see traces from the application. Is there a way to accomplish this? OR is there a way to find out if javaagent is enabled, based on which I could initialize SDK.

[anuraaga]

@shivchelwa Nice timing, we just added a point to the documentation on how to configure the agent to only respect manual (application) instrumentation. Does it work for you?

open-telemetry/opentelemetry-java-instrumentation@f3334c3

[shivchelwa]

@anuraaga, looks like the suggested properties totally shuts out auto-instrumentation. I was looking for something to provide me traces from both auto and manual. With manual I can generate and capture telemetry from my application and with auto I could reap the benefits of instrumented libraries(which are used in my application).

And I could do that by enabling auto-instrumentation(javaagent) and instrumenting my application using API. But, in cases where javaagent is not used to start application, the instrumentation added in my application is useless. To address that, I used SDK to create SdkTracerProvider. But then, I see Resource set in manual instrumentation is not used when javaagent is used.

[anuraaga]

@shivchelwa Ah so you want to be able to run your app without the agent in a way that works, transparently? Currently I think we only support the case of lean vs non-lean by still having the agent in both cases but disabling instrumentation in the lean version. The agent intentionally hides the SDK to eliminate chances of version conflicts with an application. But we have been getting requests for more programatic configuration of the agent's SDK and are tracking it in #2002, I think we need to solve it (by first coming up with an idea for a way to solve it) to support this use case.

[shivchelwa]

@anuraaga, thank you for the explanation.