Dear devs, I'd like to ask you for help with the communication incompatibility between pre-2.18.0 servers and the newer ones. What I've learned so far is that in 2.18.0 there's been a change in the REPLICATION_START_FINISH_SYNC packet, yet no new version of that packet has been introduced. There have been some additional data appended to that packet, so that newer servers expect older servers to send more data than they actually do, and older servers can't cope with the additional data they receive. The fact that until now nobody noticed that replication between pre-2.18.0 and post-2.18.0 does not work confuses me a little.
Before learning the actual reason of the incompatibility, I have developed a test which would eventually pass after the issue has been fixed. But now I see that fixing it would mean releasing a set of at least five minor bugfix releases. Shall I even attempt? If not, will you accept at least the test suite so that nothing like that happens in the future? Also mentioning the incompatibility somewhere might help others as unfortunate as me. The WIP PR is here: https://github.com/apache/activemq-artemis/pull/4144 [https://opengraph.githubassets.com/1fef362275960b2364da60ecddb76ca361b56b67aca157a2a2d25e3145d32d99/apache/activemq-artemis/pull/4144]<https://github.com/apache/activemq-artemis/pull/4144> ARTEMIS-3767 Fix replication incompatibility between pre 2.18.0 and SNAPSHOT (WIP) by jsmucr · Pull Request #4144 · apache/activemq-artemis<https://github.com/apache/activemq-artemis/pull/4144> This PR attempts to solve the issue described in https://issues.apache.org/jira/browse/ARTEMIS-3767. TL;DR replication between =<2.17.0 and newer Artemis versions is broken since 2.18.0. github.com Thanks for your suggestions. Jan
