Instrument spring-batch: item-level spans

[mateuszrzeszutek]

Another part of spring batch instrumentation, last level of span hierarchy - item-level spans.
This time I couldn't use any listeners for instrumentation, so I'm instrumenting spring batch internal classes. And the item level instrumentation is very chatty, so perhaps it should stay an optional instrumentation even if spring batch ends up being enabled by default.

[anuraaga]

It'd definitely be nice to get some spec issues going for this batch processing stuff

[mateuszrzeszutek]

Yes, definitely - I've filed a spec issue about that (now that my vacation is over I can start working on that 😄 ).

[trask]

Thanks for calling this out:

the item level instrumentation is very chatty, so perhaps it should stay an optional instrumentation even if spring batch ends up being enabled by default

It sounds like otel.instrumentation.spring-batch.item.enabled should be false by default even now then?

[mateuszrzeszutek]

It sounds like otel.instrumentation.spring-batch.item.enabled should be false by default even now then?

Yes, definitely -- done.

[mateuszrzeszutek]

By the way I ran into an interesting issue with muzzle here: when item level instrumentation was disabled and type instrumentations were not added to the list, by default the byteBuddyjava task didn't see advice classes used by those instrumentations - and thus did not register helper classes. I've changed the way those instrumentations are disabled, and now every type instrumentation is always active, but the configuration switch is moved to the advice class.