5.0 is a massive milestone. A huge thank you to everyone that's invested their time into the release. I've done a lot of testing, benchmarking, and tire kicking and it's truly mind blowing how much has gone into 5.0 and how great it is for the community.
I am a bit concerned that CASSANDRA-19668, which I found in 4.1, will also affect 5.0. This is a pretty serious bug, where using Paxos v2 + off heap memtables can cause a SIGSEV process crash. I've seen this happen about a dozen times with a client over the last 3 months. Since the new trie memtables rely on off heap, and both Trie memtables & Paxos V2 is so compelling (esp for multi-dc users), I think there's a good chance that we'll be making an already bad problem even worse, for folks that use LWT. Unfortunately, until next week I'm unable to put any time into this; I'm on vacation with my family. I wish I had been able to confirm and raise this issue as a 5.0 blocker sooner, but I've deliberately tried to keep work stuff out of my mind. Since I'm not 100% sure if this affects 5.0, I'm not blocking the RC, but I don't feel comfortable putting a +1 on a release that I'm at least 80% certain contains a process-crashing bug. I have a simple 4.1 patch in CASSANDRA-19668, but I haven't landed a commit in several years and I have zero recollection of the entire process of getting it in, nor have I spent any time writing unit or dtests in the C* repo. I ran a test of 160MM LWTs over several hours with my 4.1 branch and didn't hit any issues, but my client ran for weeks without hitting it so it's hard to say if I've actually addressed the problem, as it's a rare race condition. Fwiw, I don't need to be the one to handle CASSANDRA-19668, so if someone wants to address it before me, please feel free. It will likely take me a lot longer to deal with than someone more involved with the process, and I'd want 2 sets of eyes on it anyways given what I already mentioned previously about committing and testing. Jon On Tue, Jun 25, 2024 at 2:53 PM Mick Semb Wever <m...@apache.org> wrote: > > > . > > Proposing the test build of Cassandra 5.0-rc1 for release. >> >> sha1: b43f0b2e9f4cb5105764ef9cf4ece404a740539a >> Git: https://github.com/apache/cassandra/tree/5.0-rc1-tentative >> Maven Artifacts: >> https://repository.apache.org/content/repositories/orgapachecassandra-1336/org/apache/cassandra/cassandra-all/5.0-rc1/ >> > > > The three green CI runs for this are > - > https://app.circleci.com/pipelines/github/driftx/cassandra?branch=5.0-rc1-2 > - > https://app.circleci.com/pipelines/github/driftx/cassandra?branch=5.0-rc1-3 > - > https://app.circleci.com/pipelines/github/driftx/cassandra?branch=5.0-rc1-4 > > >
