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Accumulo, mail # user - thread safety of IndexedDocIterator


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Re: thread safety of IndexedDocIterator
William Slacum 2012-11-05, 20:29
At one point, Keith had warned me against kicking off threads inside a scan
session. Is it possible we could have a discussion on the implications of
this?

On Mon, Nov 5, 2012 at 11:30 AM, Billie Rinaldi <[EMAIL PROTECTED]> wrote:

> On Mon, Nov 5, 2012 at 11:24 AM, Sukant Hajra <[EMAIL PROTECTED]>wrote:
>
>> We noticed that IndexedDocIterator.java has the following private static
>> fields:
>>
>>     private static Text indexColf = DEFAULT_INDEX_COLF;
>>     private static Text docColf = DEFAULT_DOC_COLF;
>>
>> The init method, which sets these is synchronized.  Still, though, this
>> synchronization doesn't seem enough to allow different runs of the
>> iterator to
>> use different values for indexColf and docColf.  One run will set the
>> "Colf"
>> variables one way atomically in the synchronized init method. . . and
>> another
>> run and immediately interleave in alternate "Colf" settings, which breaks
>> the
>> original iterator run.
>>
>> For now, we're not touching the indexColf and docColf, just leaving it as
>> the
>> defaults.
>>
>> We're not blocked by this.  We're just curious if there's a bug in this
>> design.
>> Also, if it's not a defect, we're interested in learning what system
>> invariant
>> of iterator execution makes this not a problem.
>>
>
> Sounds like a bug.  Feel free to open a ticket!
>
> Billie
>
>
>
>>
>> Thanks,
>> Sukant
>>
>
>