What are those patches exactly? Comparing the ported version of 3.5 with master I’ve only found 2 patches which are missing:
ZOOKEEPER-3146 Limit the maximum client connections per IP in NettyServerCnxnFactory ZOOKEEPER-3177 Refactor request throttle logic in NIO and Netty to keep the same behavior and make the code easier to maintain None of them are critical I would say. Is there anything else I’m missing? Andor > On 2019. Jan 4., at 16:27, Enrico Olivelli <eolive...@gmail.com> wrote: > > Il giorno ven 4 gen 2019 alle ore 14:23 Andor Molnar > <an...@apache.org <mailto:an...@apache.org>> ha scritto: >> >> Hi team / Enrico, >> >> I’d like to get feedback from the community on the following patch (moving >> the discussion from GitHub to here): >> >> https://issues.apache.org/jira/browse/ZOOKEEPER-3204 >> <https://issues.apache.org/jira/browse/ZOOKEEPER-3204> >> https://github.com/apache/zookeeper/pull/753 >> <https://github.com/apache/zookeeper/pull/753> >> >> In a nutshell: looks like that Netty 3.10 is broken under Java 11: it >> doesn’t properly close the underlying socket (probably not closing the >> registered NIO selectors) and reconfig tests are unable to re-bind the >> ports. This problem is similar that we already fixed in NIO with the >> following patch: >> https://github.com/apache/zookeeper/commit/c3babb94275ad667dc71c10dcb08a383a3c154c2 >> >> <https://github.com/apache/zookeeper/commit/c3babb94275ad667dc71c10dcb08a383a3c154c2> >> The problem doesn’t show up on trunk which has been recently upgraded to >> Netty 4. >> >> Repro: >> - Start embedded ZK, stop it and try to restart on the same port, or >> - Start normal ensemble and reconfig to use different (client) port. Then >> reconfig back to the original port which should fail. (that’s the scenario >> which is covered in ReconfigTest) >> >> I created the above patch (#753) to backport Netty 4 upgrade to 3.5 and it >> fixes the problem with Java 11 (it doesn’t cause regression in the >> pre-commit build either), but Enrico is having concerns about making such >> big change before the release. >> >> I tend to agree, but let’s see what are the options. >> >> Thoughts: >> - Do we have to fix this? - Yes. Java 11 is LTS and I the bug is critical. >> - Can we fix Netty 3? - Maybe. Let’s say we find the bug in Netty 3, what >> can we do? >> a) We cannot workaround from ZooKeeper itself and have to submit a >> pull request for Netty. I think it’s quite unlikely that they will accept >> the change given it’s not a security bug, but even if they did, only the >> upgraded version of Netty 3 would work properly with ZooKeeper. Err. >> b) We can workaround it from ZooKeeper: that could be option #1, but I >> have a strong feeling about it’s not going to be the case. >> - Shall we upgrade to Netty 4? - this is option #2 >> >> Please share your thoughts, maybe you know about an option #3. > > Thank you Andor > > I have thought more about this problem, and I have checked that Netty > 3 is really dead/unmantained (last release in 2016). > If I understand correctly there is no easy workaround (nothing without > hacking Netty 3 internals) > > As soon as we will declare 3.5.5 "stable" the world will hopefully > abandon 3.4 and switch to 3.5 + Netty (because of SSL support). > The network stack is very important so it is better to have Netty 4 as > foundation, I am thinking about security issues, we won't make an > "hotfix" release with the switch to Netty 4 because there is a bad bug > in Netty 3. > So better to switch now. > > But Facebooks friends, expecially @ivmaykov did a lot of bugfixes > around Netty on master branch, we must be sure that what we are > delivering in 3.5.5 is stable. > > We will also have to state clearly in the "release notes" that Netty > version is changed, as this may have a non trivial impact to memory > usage (i.e. Netty 4 uses more Direct memory by default) > > So to recap my final opinion: +1 to switch to Netty 4 if we take care > of port all of the fixes around Netty 4 from master branch and we > state the switch clearly in the release notes > > Enrico > >> >> Regards, >> Andor
