Reapply rack response body instrumentation #1099
Assignees
Labels
Comments
tombruijn
added a commit
that referenced
this issue
Jul 2, 2024
Instrument what happens when a Rack response body is read and closed. We instrument these events by wrapping the response body in the appropriate response body BodyWrapper subclass, depending on the response object type. This change was previously sent in as PR #1037 and reverted in #1052. We saw issues with multiple requests reported in the same transaction. This problem occurred when there was an error in the middleware stack, and the BodyWrapper never closed the response body. I've removed any transaction complete logic from the BodyWrapper in the original PR. We now have a Rack EventHandler that ensures the transaction is always closed per request, even when such an error scenario occurs again. The only scenario in which we don't support this response body instrumentation is when no EventHandler is present in the middleware stack. This level of support is acceptable to me. We want people to use the EventHandler. Most of our automatic instrumentations are updated to add it to the middleware stack. From the original commit: 7da96e7 > Some work might be getting done within a Rack response body. For > example, when ActionController::Streaming is used, or when a Rack app > elects to stream a response. > > The Rack SPEC doc defines the behavior in sufficient detail to wrap > this into the current AppSignal transaction. > > Sadly, there is some work involved in supporting all the right > methods, so just "one-size-fits-all" wrapper will not quite work. Part of #1099 Co-authored-by: Julik Tarkhanov <me@julik.nl>
tombruijn
added a commit
that referenced
this issue
Jul 8, 2024
Instrument what happens when a Rack response body is read and closed. We instrument these events by wrapping the response body in the appropriate response body BodyWrapper subclass, depending on the response object type. This change was previously sent in as PR #1037 and reverted in #1052. We saw issues with multiple requests reported in the same transaction. This problem occurred when there was an error in the middleware stack, and the BodyWrapper never closed the response body. I've removed any transaction complete logic from the BodyWrapper in the original PR. We now have a Rack EventHandler that ensures the transaction is always closed per request, even when such an error scenario occurs again. The only scenario in which we don't support this response body instrumentation is when no EventHandler is present in the middleware stack. This level of support is acceptable to me. We want people to use the EventHandler. Most of our automatic instrumentations are updated to add it to the middleware stack. From the original commit: 7da96e7 > Some work might be getting done within a Rack response body. For > example, when ActionController::Streaming is used, or when a Rack app > elects to stream a response. > > The Rack SPEC doc defines the behavior in sufficient detail to wrap > this into the current AppSignal transaction. > > Sadly, there is some work involved in supporting all the right > methods, so just "one-size-fits-all" wrapper will not quite work. Part of #1099 Co-authored-by: Julik Tarkhanov <me@julik.nl>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Reapply the reverted PR #1037.
I think we should do this after the Rack middleware refactor #329, so we can ensure the request transaction is always closed and we can't have transactions leak across multiple requests.
I hope we can change the response body instrumentation so that it's not in charge of completing the request transaction.
The text was updated successfully, but these errors were encountered: