What's the use case for `exception.escaped`?

[trask]

What's the use case for exception.escaped?

We have never captured this in Java instrumentation, and no one has ever asked for it, so I'm wondering if it's really useful?

Assuming there are use cases for it, are they compelling enough to justify capturing it by default (as recommended) or should it be opt-in?

[scheler]

The trace sdk in python seems to be setting this attribute to True automatically - see this - and a relevant example would be the following - .

try:
    with tracer.start_as_current_span("example-span") as span:
        print("Inside the span.")
        # Simulate an operation that raises an exception
        raise ValueError("An intentional error within the span.")
       # the span automatically ends here but the exception lives on
except Exception as e:
    print(f"Exception outside span: {e}")
    # Exception can propagate here after the span is closed
    raise

The documentation for recording an exception has a pseudo-java example - maybe we should replace it with the python example? The Java example still demonstrates the purpose of this attribute.

[trask]

thanks @scheler

I think the question I'm trying to ask is what would a user do with this piece of information (exception.escaped)? and is that use case compelling enough to justify capturing it by default (as recommended) or should it be opt-in if it's a very narrow use case

[scheler]

@trask I think the python community would know more on this since the spec language for this attribute includes python terms and is likely written by someone from python side. (ContextManager / exit method).

[lmolkova]

I was making a case for this attribute in open-telemetry/opentelemetry-specification#4333, but I no longer think it's necessary.

I believe the use-case behind it is the ability to distinguish handled exceptions from unhandled ones.

If we report exceptions on logs/events, we have severity to capture it - Error+ severity is for exceptions that went unhandled and wither failed incoming call, background operation, or crashed the process. Warning and lower is for exceptions that are being handled or may be handled by the caller.

there is no severity on the span event and we should deprecated this attribute along with span events.

[lmolkova]

The attribute is now deprecated in #1716