I am using Pulsar 3.2.1, the cluster has been running for 24h. I've ingested around 30k messages during that time. It looks like some messages were not delivered and are in the backlog, but were acked. Happens on Shared and Exclusive subscriptions. One of the affected topic is:

__change_events

, therefore I don't think it's related to my code. All my affected topics has subscriptions with readCompacted set to

true

. Anyone faced this issue and knows the potential cause/solution? I am using KAAP

Yes I stumbled upon the same issue: all messages acknowledged, but some still appear in the backlog (shared topics without compaction). I do not know the cause / solution. The issue seems related to the Java client since v3 (I do not have the issue with Pulsar 3+ and client 2.11)

For now I've changed Pulsar release to 3.1 (3.1.3), for now no issues, but we'll see ...

Which client do you use?

The client is 3.2.0

There's a bug report and fix that matches the description in this thread: issue https://github.com/apache/pulsar/issues/22352 and fix https://github.com/apache/pulsar/pull/22353

@Lari Hotari I am on a conference and just downgraded the version to get rid of the problem.

@Michał Cukierman the fixed version isn't available yet. It is a useful contribution to Pulsar to validate that snapshot or release candidate versions fix a problem or don't cause regressions. We need more Pulsar users that would be willing to contribute to Pulsar in this way. /cc @Gilles Barbier

Sure, I am on Adobe Summit on a booth, cannot try the SNAPSHOT version. I had 50 visitors yesterday, looking for the same number today 😉

Pulsar 3.2.2 and 3.0.4 will contain the required 2 fixes to this problem. Both releases are in release candidate phase and in release voting. Will be released on Tuesday or Wednesday. https://lists.apache.org/thread/qp0bto5fbto1djg0lro9k1pmfcrkq1hv https://lists.apache.org/thread/pl5c0hx2z19kg4v76lgxhfxxccmcoj56

@Lari Hotari sure - what’s the easiest way to access it?

@Gilles Barbier the release vote emails contain the links. For Maven deps, there's a staging repository url. There's also docker images. Links in the previous message https://apache-pulsar.slack.com/archives/C5Z4T36F7/p1711715458390569?thread_ts=1711399325.293829&cid=C5Z4T36F7

Is there an update of the java client as well in this version?

Yes, that's available via the maven staging repository url. The voting emails contain the URLs.

https://repository.apache.org/content/repositories/orgapachepulsar-1286 seems to be unavailable

@Gilles Barbier The version has been released and is currently syncing to maven central. It should be available within a few hours.

ok - I will test it today.

sounds good. The 3.0.4 and 3.2.2 versions aren't yet synced in Maven central. https://apache-pulsar.slack.com/archives/C5Z4T36F7/p1712141547255429 . There has been some incident in the repository sync and it is being resolved by Sonatype.

it seems to work now

ok great

ok. Same for 3.0.4 - bug fixed for me 🙂

I will have a look tomorrow or next week. Will let you know if we encounter the issue again. Thanks!