High CPU Usage after switching to CompatibleFieldSerializer

[ankit-harness]

Describe the bug

We recently switched to CompatibleFieldSerializer in our codebase. After that we have had few instances where a thread ends up consuming very high CPU in our service. We have to restart our service instance to fix that. Here's the stacktrace for the thread -

main-app-pool-97571" #4516363 prio=5 os_prio=0 cpu=1058305.52ms elapsed=1212.28s tid=0x00007f6620d90400 nid=0x57dd8 runnable  [0x00007f6611c19000]
   java.lang.Thread.State: RUNNABLE
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
at com.esotericsoftware.kryo.io.OutputChunked.flush(OutputChunked.java:64)
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
at com.esotericsoftware.kryo.io.OutputChunked.flush(OutputChunked.java:64)
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
at com.esotericsoftware.kryo.io.OutputChunked.flush(OutputChunked.java:64)
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
at com.esotericsoftware.kryo.io.OutputChunked.flush(OutputChunked.java:64)
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
at com.esotericsoftware.kryo.io.OutputChunked.flush(OutputChunked.java:64)
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
at com.esotericsoftware.kryo.io.OutputChunked.flush(OutputChunked.java:64)
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
at com.esotericsoftware.kryo.io.OutputChunked.flush(OutputChunked.java:64)
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
at com.esotericsoftware.kryo.io.OutputChunked.flush(OutputChunked.java:64)
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
at com.esotericsoftware.kryo.io.OutputChunked.flush(OutputChunked.java:64)
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
at com.esotericsoftware.kryo.io.OutputChunked.flush(OutputChunked.java:64)
at com.esotericsoftware.kryo.io.Output.flush(Output.java:186)
   Locked ownable synchronizers:
<0x000000043f002148> (a java.util.concurrent.ThreadPoolExecutor$Worker)

I think this issue is same as #838. We wanted to try out the fix done for this issue. But, it's not available in 4.0.2 which is the version we are using. Upgrading to 5.x.x is going to be a huge effort as it has breaking changes.

Can we release 4.0.3 with this fix?

[theigl]

Hi @ankit-harness. Please create a PR that applies the fix to the kryo-4 branch.

I had no plans to release another 4.x version, but I will consider it in this case.

[ankit-harness]

Thanks a lot @theigl . I have created the PR - #978

[theigl]

Thank you @ankit-harness! I will try to release a new Kryo 4 version next week. First I have to look through all improvements that were made to Kryo 5 that could potentially be backported.

I have not done a release of 4.x since I took over as maintainer of this project. I hope the release process still works after 4 years ;)

[ankit-harness]

Eagerly waiting for the release with extra goodness. 😀

[ankit-harness]

Hi @theigl , any update on this?

[theigl]

Not yet. I need a couple of hours of spare time to get the 4.x branch into a releasable state again. I'll let you know when I cut the release.

[theigl]

@ankit-harness: I have just released 4.0.3.

I cherry picked and applied two additional fixes concerning InputChunked and OutputChunked.

Please verify that this release works for you.

[ankit-harness]

Thanks a lot @theigl . I will try it out. Is artifact uploaded to maven central repo too?

[theigl]

Yes. It should make it to central in the next hours.