Log exception details when Message.type == TMessageType.EXCEPTION

[Froodulous]

Currently, when a message of type EXCEPTION is returned by a thrift service, the server-side span is tagged as an error. However, no details of the exception are logged to the span. When the SpanProcessor catches an exception, it creates error logs and adds them to the span. Can the library do the same when the exception is returned by thrift? Just the type of the exception being returned would be useful.

[malafeev]

problem that org.apache.thrift.ProcessFunction doesn't do anything with Exception except logging:

catch (Exception ex) {
      LOGGER.error("Internal error processing " + getMethodName(), ex);
      if(!isOneway()) {
        result = new TApplicationException(TApplicationException.INTERNAL_ERROR,
            "Internal error processing " + getMethodName());
        msgType = TMessageType.EXCEPTION;
      }
}

So exception is not accessible from TProtocolDecorator.

[Froodulous]

I see. That is a pain. So there's basically no way of getting the details of that exception without extending the ProcessFunction class, and that class is referenced directly by code generated by the thrift compiler. You would need a change to thrift itself to be able to add the details of the exception to the span.