apache / apache/pulsar-client-cpp

[Bug] [ARM] Partially acknowledged batches are not redelivered

Open
#424 6 comments 0 reactions 0 assignees View on GitHub
Dominant language
C++
Stars
71
Forks
90
Avg merge
2h 33m
Merged PRs (30d)
3

Description

### Search before asking

- [X] I searched in the [issues](https://github.com/apache/pulsar-client-cpp/issues) and found nothing similar.

### Version

Debian GNU/Linux 10 (buster), aarch64 (but the executable is arm32), pulsar-client-cpp 3.3.0

### Minimal reproduce step

1. Send a batch of events to the Pulsar broker (in our reproduction, it is a batch size of 309).
2. Receive these messages (we're using `pulsar::Consumer::receive` in a loop), while continuously acknowledging them asynchronously (acknowledgements are done using `pulsar::Consumer::acknowledge(const MessageId &messageId)`, where `messageId` is `pulsar::Message::getMessageId`).
3. Terminate the program during the middle of receiving a batch (we're terminating after having received and acknowledged the 190/309 events from a batch).
4. Resume the program.

### What did you expect to see?

All of the events in the batch re-sent.

### What did you see instead?

None of the events in the batch, _including the ones never received_ are re-sent.

### Anything else?

- We log the result of the acknowledgement in the callback method, which shows us that the most we've acknowledged is the `190th` message in a batch.
- Exclusive subscription.
- Running it on Gravitron2/3 processors.
- We've used the same broker and test with an x86_64 Pulsar 3.3.0 Pulsar client, and we've had no issues (RHEL8).
- We can actively see missing messages - we are just sending consecutive numbers and logging them. We're missing exactly 119, the amount remaining in the batch that we've not fully acknowledged.
- We've tried not immediately terminating - i.e. we stop receiving messages but continue to process any callbacks, to validate that we're just not seeing 119 callbacks missing, and nothing.

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

Contributor guide

Open the contributing guide

Assessment

This issue has not been assessed yet.

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.