The last time paxos v2 blocked us in CASSANDRA-19617 which also affected 4.1, I didn't get a sense of strong usage from the community, so I agree that RC shouldn't be blocked but this can get fixed before GA. +1 from me.
Kind Regards, Brandon On Tue, Jun 25, 2024 at 11:11 PM Jon Haddad <j...@jonhaddad.com> wrote: > > 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 >> >>
