GitHub user shanthoosh opened a pull request:

    https://github.com/apache/samza/pull/496

    SAMZA-1692: Standalone stability fixes.

    - Currently, on session expiration processorListener with incorrect 
generationId is registered with zookeeper(ZkUtils generationId is incremented 
on reconnect but the generationId in processorListener is zero all the time). 
When a session reconnect happens to a processor successive to leader, leader 
expiration event will be skipped. This will prevent leader re-election on a 
current leader death and will stall the processors group. Fix is to 
reinstantiate and then register processorChangeListener on session expiration.
    - Add processorId to debounce thread name (this can aid debugging when 
multiple processors are running within a jvm).
    - After ScheduleAfterDebounceTime queue is shutdown, don't accept new 
schedule requests. Current ZkJobCoordinator shutdown sequence comprise of the 
following steps
         - Shutdown the ScheduleAfterDebounceTime queue.
         - Stop the zkClient  and relinquish it's resources.
    
    After we shutdown ScheduleAfterDebounceTime and before zkclient is stopped, 
any new operations can be scheduled in ScheduleAfterDebounceTime queue. This 
will result in RejectedExecutionException, since executorService is stopped.
    
    ```
    Caused by: java.util.concurrent.RejectedExecutionException: Task 
java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask@23f962a8 
rejected from java.util.concurrent.ScheduledThreadPoolExecutor@43408be8
    ```

You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/shanthoosh/samza master

Alternatively you can review and apply these changes as the patch at:

    https://github.com/apache/samza/pull/496.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #496
    
----
commit 5f9e5bdd4adc9ba14ef06b3de536787cb36cd0cc
Author: Shanthoosh Venkataraman <svenkataraman@...>
Date:   2018-04-30T04:28:14Z

    SAMZA-1692: Standalone stability fixes.
    
    - Currently, on session expiration processorListener with incorrect 
generationId is registered with zookeeper(ZkUtils generationId is incremented 
on reconnect but the generationId in processorListener is zero all the time). 
When a session reconnect happens to a processor successive to leader, leader 
expiration event will be skipped. This will prevent leader re-election on a 
current leader death and will stall the processors group. Fix is to 
reinstantiate and then register processorChangeListener on session expiration.
    - Add processorId to debounce thread name (this can aid debugging when 
multiple processors are running within a jvm).
    - After ScheduleAfterDebounceTime queue is shutdown, don't accept new 
schedule requests. Current ZkJobCoordinator shutdown sequence comprise of the 
following steps
         - Shutdown the ScheduleAfterDebounceTime queue.
         - Stop the zkClient  and relinquish it's resources.
    
    After we shutdown ScheduleAfterDebounceTime and before zkclient is stopped, 
any new operations can be scheduled in ScheduleAfterDebounceTime queue. This 
will result in RejectedExecutionException, since executorService is stopped.
    
    ```
    Caused by: java.util.concurrent.RejectedExecutionException: Task 
java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask@23f962a8 
rejected from java.util.concurrent.ScheduledThreadPoolExecutor@43408be8
    ```

----


---

Reply via email to