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From William Slacum <wilhelm.von.cl...@accumulo.net>
Subject Re: 'scanner closed' error
Date Mon, 04 Aug 2014 01:45:09 GMT
I have seen issues if I don't have an explicit close on the batch scanner.
When I don't have the close, the gc ends up calling `finalize()` which
closes the thread pool. Basically, the work around is to manage the
lifetime of the instance yourself, rather than leave it up to fate.


On Sun, Aug 3, 2014 at 7:03 PM, Don Resnik <
don.resnik@objectivesolutions.com> wrote:

> Josh,
>
> Thanks for the response.  I did see that ticket in my initial research.
> If I understood correctly, that ticket makes it sound like the scanner was
> closed programmatically with threads still running, so there was not really
> an error.  In my case, the error is coming up well before the scanner has
> completed.  We did not intend to programmatically close the scanner where
> is it closing on us, but I will confirm this week that we do not have a
> condition that would cause the scanner to close prematurely with threads
> still running.
>
> Thanks,
>
> Don Resnik
>
>
>
>
> On Sun, Aug 3, 2014 at 5:05 PM, Josh Elser <josh.elser@gmail.com> wrote:
>
>> Don,
>>
>> Does this describe your error?
>>
>> https://issues.apache.org/jira/browse/ACCUMULO-607
>>
>>
>> On 8/3/14, 4:50 PM, Don Resnik wrote:
>>
>>>
>>>
>>> I have some query logic that uses a stack of custom iterators with a
>>> batch scanner.  The query begins to return values but then stops with a
>>> 'scanner closed' error.  The only reference I can find to scanner closed
>>> in the src is in TabletServerBatchReaderIterator.  I can see that the
>>> error is thrown when the query thread pool is shutdown, but I am not
>>> sure why this is happening.  This query logic works on a single node
>>> instance, but I get the scanner closed error when running on a multi-node
>>> cluster.
>>>
>>> So far the stack traces have not been very helpful and we are not sure
>>> where or how to troubleshoot this.  Any info on what conditions would
>>> lead to a scanner closed error and where to begin looking to resolve
>>> would be appreciated.
>>>
>>> Thanks,
>>>
>>
>

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