lhotari edited a comment on pull request #59: URL: https://github.com/apache/pulsar-helm-chart/pull/59#issuecomment-682162804
> [bin/pulsar](https://github.com/apache/pulsar/blob/master/bin/pulsar#L314) script already uses `exec` to running the process. Are you sure that we need this change? @sijie Yes, it's needed. `exec` is a shell built-in and it will only be able to replace it's current shell, not any parent shells. Therefore the exec in `bin/pulsar` won't affect the top-level shell (`command: ["sh", "-c"]`). You can quickly check the behavior without exec in docker: ``` docker run --name pulsar-standalone --rm -it --entrypoint '/bin/sh' apachepulsar/pulsar:2.6.1 -c 'bin/apply-config-from-env.py conf/standalone.conf && bin/pulsar standalone' ``` ``` $ docker exec -it pulsar-standalone ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 0 19:56 pts/0 00:00:00 /bin/sh -c bin/apply-config-from root 7 1 99 19:56 pts/0 00:01:01 /usr/local/openjdk-8/bin/java -c root 685 0 10 19:56 pts/1 00:00:00 ps -ef ``` As it can be seen, /bin/sh is PID 1 in the docker container when exec isn't used. When issuing `docker stop pulsar-standalone`, one can see that the Pulsar process doesn't receive any signals. No console output is produced. The stop command waits 10 seconds and kills the container processes. after adding `exec` this changes: ``` docker run --name pulsar-standalone --rm -it --entrypoint '/bin/sh' apachepulsar/pulsar:2.6.1 -c 'bin/apply-config-from-env.py conf/standalone.conf && exec bin/pulsar standalone' ``` ``` $ docker exec -it pulsar-standalone ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 99 19:58 pts/0 00:00:14 /usr/local/openjdk-8/bin/java -c root 253 0 0 19:58 pts/1 00:00:00 ps -ef ``` the `java` process is now PID 1 and it will receive OS signals as recommended in Docker and k8s documentation (links provided in the issue description). The graceful shutdown can now be verified by issuing `docker stop pulsar-standalone`. The shutdown process in Pulsar starts and the console is filled with log entries which confirm the graceful shutdown. For example: ``` 04:33:26.011 [Thread-1] INFO org.apache.bookkeeper.bookie.Journal - Shutting down Journal 04:33:26.011 [ForceWriteThread] INFO org.apache.bookkeeper.bookie.Journal - ForceWrite thread interrupted 04:33:26.011 [BookieJournal-3181] INFO org.apache.bookkeeper.bookie.Journal - Journal exits when shutting down 04:33:26.011 [BookieJournal-3181] INFO org.apache.bookkeeper.bookie.Journal - Journal exited loop! 04:33:26.012 [Thread-1] INFO org.apache.bookkeeper.bookie.Journal - Finished Shutting down Journal thread 04:33:26.012 [Bookie-3181] INFO org.apache.bookkeeper.bookie.Bookie - Journal thread(s) quit. ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
