Bumping this thread so it’s current.
> On Feb 14, 2022, at 6:09 AM, Christophe Bornet <bornet.ch...@gmail.com> wrote:
>
> Big +1
>
> Le lun. 14 févr. 2022 à 14:54, Nicolò Boschi <boschi1...@gmail.com> a
> écrit :
>
>> Dear Pulsar community,
>>
>>
>> I would like to start a discussion about having a plan to make Pulsar
>> runtime-compatible with JDK 17.
>>
>>
>> The goal is to run Pulsar using JDK17 at runtime, benefitting from the
>> latest JVM performance improvements and features.
>>
>>
>> The non-goal is to deprecate JDK8 or JDK11 runtime compatibility. The java
>> compiler *release* flag will be kept to 8 (this change deserves another
>> discussion thread).
>>
>>
>> *Build*
>>
>>
>> At the moment, the build command (mvn clean install -DskipTests) works well
>> using JDK17.
>>
>>
>> We fixed a lot of unit tests and other issues found using JDK17 removing
>> PowerMockito improper usages: https://github.com/apache/pulsar/pull/14098
>>
>> Other small pulls were merged fixing other kinds of issues (all related to
>> the tests themself and not the production code).
>>
>>
>> *Runtime compatibility*
>>
>>
>> Currently I haven't seen severe issues running Pulsar on JDK17.
>>
>> For testing purposes, I’ve created a simple image which pulls the Pulsar
>> master and installs JDK17-zulu instead of JDK11.
>>
>> I've tried running the docker image in a Kubernetes environment (deploying
>> it with the Apache Pulsar helm chart), testing a few scenario:
>>
>> * Produce and consume message (pulsar cli, pulsar perf)
>>
>> * Functions/Connectors (embedding Nar files)
>>
>>
>> All the components/pods are working without visible issues. However my
>> tests weren't under high traffic and a lot of Pulsar features were not
>> involved in the tests.
>>
>>
>> The main problems might be caused by the restrictions around reflection
>> usage introduced in JDK17 JEP 403: Strongly Encapsulate JDK Internals
>> <https://openjdk.java.net/jeps/403>
>>
>> We may need to unlock some packages to reflection to keep some
>> optimizations, for example for BookKeeper Native IO (
>>
>> https://github.com/apache/bookkeeper/blob/master/bookkeeper-server/src/main/java/org/apache/bookkeeper/util/NativeIO.java#L98
>> )
>>
>>
>> It would be great to chase other improvements to be explicitly unlocked for
>> other low-level libraries (Netty, GRPC...)
>>
>>
>>
>> *Continuous Integration*
>>
>> To maintain the support for JDK17 we need to switch all the CI jobs to
>> JDK17; the idea is to replace JDK11 completely. We could - not sure - keep
>> a single job for JDK11 compatibility, like we do with JDK8.
>>
>>
>>
>> *Docker distribution*
>>
>> After we get the Pulsar master CI stable, we can move the official Docker
>> images to JDK17 (currently on JDK11).
>>
>>
>>
>> *Proposal plan*
>>
>> We can start moving the CI to JDK17 after the branch-2.10 has been cut and
>> targeting JDK17 runtime support for Pulsar 2.11
>>
>>
>>
>>
>> WDYT?
>>
>> BR,
>> Nicolò Boschi
>>
