Re: [HACKERS] parallel.c oblivion of worker-startup failures - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: [HACKERS] parallel.c oblivion of worker-startup failures
Date
Msg-id CAA4eK1+y2asrJRS3XG2Pwwy8_Ypcv=arrL33_8U0Bj9hY9Hpeg@mail.gmail.com
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In response to Re: [HACKERS] parallel.c oblivion of worker-startup failures  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: [HACKERS] parallel.c oblivion of worker-startup failures  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
On Tue, Dec 12, 2017 at 9:00 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> On Mon, Dec 11, 2017 at 11:27 PM, Robert Haas <robertmhaas@gmail.com> wrote:
>> On Sun, Dec 10, 2017 at 11:07 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>>> Okay, see the attached and let me know if that suffices the need?
>>
>> +             * Check for unexpected worker death.  This will ensure that if
>> +             * the postmaster failed to start the worker, then we don't wait
>> +             * for it indefinitely.  For workers that are known to be
>> +             * launched, we can rely on their error queue being freed once
>> +             * they exit.
>>
>> Hmm.  Is this really true?  What if the worker starts up but then
>> crashes before attaching to the error queue?
>>
>
> If the worker errored out before attaching to the error queue, then we
> can't rely on error queue being freed.  However, in that case, the
> worker status will be BGWH_STOPPED.  I have adjusted the comment
> accordingly.
>

In particular, if the worker crashed (say somebody forcefully killed
the worker), then I think it will lead to a restart of the server.  So
not sure, adding anything about that in the comment will make much
sense.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com


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