tgw-thirdfort opened a new issue, #35295: URL: https://github.com/apache/beam/issues/35295
### What happened? When streaming data from PubSub, there are two broad options: 1. Create a new subscription on a topic 2. Use an existing subscription for a topic These are mutually exclusive. However, the pubsubio package does not guarantee this exclusion - as can be seen [here](https://github.com/apache/beam/blob/master/sdks/go/pkg/beam/io/pubsubio/pubsubio.go#L74), if `ReadOptions` contains a non-empty Subscription, this is set on the existing [payload](https://github.com/apache/beam/blob/master/sdks/go/pkg/beam/model/pipeline_v1/beam_runner_api.pb.go#L3659) which already has the Topic set. This violates the guarantees that the comments on the `pipepb.PubSubReadPayload` assume - that "Exactly one of topic or subscription should be set.". In practice, when used in a Dataflow job, I observe that a new subscription is created - it seems the fact that `Topic` is specified means approach 1 (above) wins out. If I make the following change to the `pubsubio` code I observe the behaviour I expect when running in Dataflow (no subscription created except for the tracker subscription if custom timestamps are used): ```go if opts != nil { payload.IdAttribute = opts.IDAttribute payload.TimestampAttribute = opts.TimestampAttribute if opts.Subscription != "" { payload.Topic = "" payload.Subscription = pubsubx.MakeQualifiedSubscriptionName(project, opts.Subscription) } payload.WithAttributes = opts.WithAttributes } ``` ### Issue Priority Priority: 2 (default / most bugs should be filed as P2) ### Issue Components - [ ] Component: Python SDK - [ ] Component: Java SDK - [x] Component: Go SDK - [ ] Component: Typescript SDK - [ ] Component: IO connector - [ ] Component: Beam YAML - [ ] Component: Beam examples - [ ] Component: Beam playground - [ ] Component: Beam katas - [ ] Component: Website - [ ] Component: Infrastructure - [ ] Component: Spark Runner - [ ] Component: Flink Runner - [ ] Component: Samza Runner - [ ] Component: Twister2 Runner - [ ] Component: Hazelcast Jet Runner - [x] Component: Google Cloud Dataflow Runner -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@beam.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
