Update on

On Friday, November 27, 2020, EffiSYS / Martin Querleu <
martin.querleu@effisys.fr> wrote:

Hello

We use PG 11.9 and are encountering the problem with connection limit and
parallel workers aborting a totally valid query ("CONTEXT: parallel worker"
error)

I found there was a thread concerning this problem and even a patch was
developed: /messages/by-id/CAB7nPqQKJPgNkg0VQguUP
1u%2BpDdk1qF16Qh5MtDQEtSMG4S-fg%40mail.gmail.com but no news since 2017

Do you know the status of the patch or a modification to remove the
parallel worker from the connection count against user (also server?)
CONNECTION_LIMIT or to just not launch workers if not possible?

That thread was resolved with a committed patch [1] mid-thread, then got
hijacked a bit...

https://github.com/postgres/postgres/commit/f1169ab501ce90e035a7c6489013a1d4c250ac92

David J.

Hello David

After reading the commit I understand it modifies the management so that
parallel workers don't count against connection_limit so I don't
understand why I experience the problem
What do you mean by "hijacked"?

Best regards
Martin

On 27/11/2020 19:30, David G. Johnston wrote:

On Friday, November 27, 2020, EffiSYS / Martin Querleu
<martin.querleu@effisys.fr <mailto:martin.querleu@effisys.fr>> wrote:

Hello

We use PG 11.9 and are encountering the problem with connection
limit and parallel workers aborting a totally valid query
("CONTEXT: parallel worker" error)

I found there was a thread concerning this problem and even a
patch was developed:
/messages/by-id/CAB7nPqQKJPgNkg0VQguUP1u+pDdk1qF16Qh5MtDQEtSMG4S-fg@mail.gmail.com
</messages/by-id/CAB7nPqQKJPgNkg0VQguUP1u+pDdk1qF16Qh5MtDQEtSMG4S-fg@mail.gmail.com&gt;
but no news since 2017

Do you know the status of the patch or a modification to remove
the parallel worker from the connection count against user (also
server?) CONNECTION_LIMIT or to just not launch workers if not
possible?

That thread was resolved with a committed patch [1] mid-thread, then
got hijacked a bit...

https://github.com/postgres/postgres/commit/f1169ab501ce90e035a7c6489013a1d4c250ac92
<https://github.com/postgres/postgres/commit/f1169ab501ce90e035a7c6489013a1d4c250ac92&gt;

David J.

--
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EffiSYS (www.effitrace.fr - www.logistique-e-commerce.fr)
martin.querleu@effisys.fr
3, rue Gustave Delory
59000 Lille
Tél: +33 9 54 28 38 76

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On Mon, Nov 30, 2020 at 2:04 AM EffiSYS / Martin Querleu <
martin.querleu@effisys.fr> wrote:

Hello David

After reading the commit I understand it modifies the management so that
parallel workers don't count against connection_limit so I don't understand
why I experience the problem

Nor do I. Hoping a -hacker responds here, I just wanted to comment about
the thread/patch that you mentioned.

What do you mean by "hijacked"?

After David's patch got posted, ending the thread in theory, Peter added a
slightly related patch to the thread, "hijacking it" to a new purpose.
What likely happened (though I didn't look) is that the new patch was
realized to have been misplaced and moved to a new thread, but no one noted
that on the old thread and so it looks as if that thread went unresolved if
one doesn't read closely and assume that the "I'll commit this tomorrow"
actually happened - which it did but no link to the commit was added to the
thread.

David J.