Gabriel Reid commented on HADOOP-14331:

FWIW, I discovered this issue when I started leveraging the code in 
HadoopScheduledThreadPoolExecutor for an external project. I made a few 
unsuccessful attempts to fix the issue in the code as it's currently 
implemented, but in the end found that it was a lot easier to just re-implement 
HadoopScheduledThreadPoolExecutor and HadoopThreadPoolExecutor to just wrap all 
submitted Runnables and Callables with a wrapper which catches and logs any 
exception thrown from the underlying Runnable/Callable. 

This is the approach that I would suggest here -- if that sounds good, let me 
know and I'll add a patch to do this.

> HadoopScheduledThreadPoolExecutor broken for periodic task running
> ------------------------------------------------------------------
>                 Key: HADOOP-14331
>                 URL: https://issues.apache.org/jira/browse/HADOOP-14331
>             Project: Hadoop Common
>          Issue Type: Bug
>          Components: common
>    Affects Versions: 3.0.0-alpha3
>            Reporter: Gabriel Reid
>         Attachments: HADOOP-14331_demonstrate_bug.patch
> The HadoopScheduledThreadPoolExecutor (introduced in HADOOP-12749) is broken 
> for the scheduling of periodic tasks (i.e. for tasks submitted with 
> {{scheduleAtFixedRate}} and {{scheduleAfterFixedDelay}}).
> The behavior of the executor with these methods is that the underlying task 
> is executed once, and then blocks the running thread indefinitely in 
> {{ExecutorHelper::logThrowableFromAfterExecute}}, meaning further executions 
> of the task won't run, and will also block the running thread from running 
> any other tasks.
> A quick scan of the source has shown me that these methods are used on 
> HadoopScheduledThreadPoolExecutor instances in several places in the code 
> base, at least in {{JobHistory}} and {{CleanerService}}, which appears to 
> mean that these classes also no longer function correctly.

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