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Commits from this thread:
2020-07-10 40316dfedc 986529ce40 ca5001a361 907283576d c3a79e7192 Remove WARNING message from brin_desummarize_range
* Intermittent BRIN failures on hyrax and lousyjack
@ 2020-06-30 16:24 Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 1 reply; 5+ messages in thread
From: Tom Lane @ 2020-06-30 16:24 UTC (permalink / raw)
To: Alvaro Herrera <alvherre@2ndquadrant.com>; +Cc: pgsql-hackers@lists.postgresql.org
Buildfarm member hyrax has shown this failure twice recently:
inline patch 1: /home/buildfarm/buildroot/HEAD/pgsql.build/src/test/regress/results/brin.out (+1/-0 lines) download inline-1.patch
--- /home/buildfarm/buildroot/HEAD/pgsql.build/src/test/regress/expected/brin.out 2020-01-23 11:10:05.730014075 -0500
+++ /home/buildfarm/buildroot/HEAD/pgsql.build/src/test/regress/results/brin.out 2020-06-30 03:50:23.651196117 -0400
@@ -490,6 +490,7 @@
INSERT INTO brintest_2 VALUES (numrange(0, 2^1000::numeric));
INSERT INTO brintest_2 VALUES ('(-1, 0)');
SELECT brin_desummarize_range('brinidx', 0);
+WARNING: leftover placeholder tuple detected in BRIN index "brinidx", deleting
brin_desummarize_range
------------------------
* Re: Intermittent BRIN failures on hyrax and lousyjack
@ 2020-07-01 03:28 Alvaro Herrera <alvherre@2ndquadrant.com>
parent: Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 1 reply; 5+ messages in thread
From: Alvaro Herrera @ 2020-07-01 03:28 UTC (permalink / raw)
To: Tom Lane <tgl@sss.pgh.pa.us>; +Cc: pgsql-hackers@lists.postgresql.org
On 2020-Jun-30, Tom Lane wrote:
> SELECT brin_desummarize_range('brinidx', 0);
> +WARNING: leftover placeholder tuple detected in BRIN index "brinidx", deleting
> I think the "crash" actually was the forced autovac cancellation we see
> here. Thus, the fact that both these animals use CLOBBER_CACHE_ALWAYS is
> not a direct cause of the failure, though it might contribute to getting
> the timing right for this to happen.
Oh, interesting.
> So (1) the comment needs to be adjusted to mention that vacuum
> cancellation is enough to create the situation, and (2) probably the
> message needs to be downgraded quite a lot, DEBUG2 or even less.
> Or maybe we could just delete the quoted stanza altogether.
Yeah, maybe deleting the whole thing is a decent answer. When I wrote
that, I was thinking that it was a very unlikely event, but evidently
that's not true.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Intermittent BRIN failures on hyrax and lousyjack
@ 2020-07-09 22:46 Tom Lane <tgl@sss.pgh.pa.us>
parent: Alvaro Herrera <alvherre@2ndquadrant.com>
0 siblings, 1 reply; 5+ messages in thread
From: Tom Lane @ 2020-07-09 22:46 UTC (permalink / raw)
To: Alvaro Herrera <alvherre@2ndquadrant.com>; +Cc: pgsql-hackers@lists.postgresql.org
Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> On 2020-Jun-30, Tom Lane wrote:
>> SELECT brin_desummarize_range('brinidx', 0);
>> +WARNING: leftover placeholder tuple detected in BRIN index "brinidx", deleting
>> So (1) the comment needs to be adjusted to mention that vacuum
>> cancellation is enough to create the situation, and (2) probably the
>> message needs to be downgraded quite a lot, DEBUG2 or even less.
>> Or maybe we could just delete the quoted stanza altogether.
> Yeah, maybe deleting the whole thing is a decent answer. When I wrote
> that, I was thinking that it was a very unlikely event, but evidently
> that's not true.
trilobite (also a CCA animal) just reported one of these, too:
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=trilobite&dt=2020-07-09%2008%3A03%3A08
Were you going to fix this, or did you expect me to?
If the latter, I lean to just deleting the message.
regards, tom lane
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Intermittent BRIN failures on hyrax and lousyjack
@ 2020-07-09 22:55 Alvaro Herrera <alvherre@2ndquadrant.com>
parent: Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 1 reply; 5+ messages in thread
From: Alvaro Herrera @ 2020-07-09 22:55 UTC (permalink / raw)
To: Tom Lane <tgl@sss.pgh.pa.us>; +Cc: pgsql-hackers@lists.postgresql.org
On 2020-Jul-09, Tom Lane wrote:
> Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> > On 2020-Jun-30, Tom Lane wrote:
> >> SELECT brin_desummarize_range('brinidx', 0);
> >> +WARNING: leftover placeholder tuple detected in BRIN index "brinidx", deleting
>
> >> So (1) the comment needs to be adjusted to mention that vacuum
> >> cancellation is enough to create the situation, and (2) probably the
> >> message needs to be downgraded quite a lot, DEBUG2 or even less.
> >> Or maybe we could just delete the quoted stanza altogether.
>
> > Yeah, maybe deleting the whole thing is a decent answer. When I wrote
> > that, I was thinking that it was a very unlikely event, but evidently
> > that's not true.
>
> trilobite (also a CCA animal) just reported one of these, too:
>
> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=trilobite&dt=2020-07-09%2008%3A03%3A08
>
> Were you going to fix this, or did you expect me to?
I have a moment now, let me have a go at it. I agree with deleting the
message. I think I'll keep the comment, slightly reworded:
/*
* Placeholder tuples only appear during unfinished summarization, and we
* hold SUE lock, so this function cannot run concurrently with
* that. Any placeholder tuples that exist must be leftovers from a
* crashed or aborted summarization; remove them silently.
*/
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Intermittent BRIN failures on hyrax and lousyjack
@ 2020-07-10 00:22 Alvaro Herrera <alvherre@2ndquadrant.com>
parent: Alvaro Herrera <alvherre@2ndquadrant.com>
0 siblings, 0 replies; 5+ messages in thread
From: Alvaro Herrera @ 2020-07-10 00:22 UTC (permalink / raw)
To: Tom Lane <tgl@sss.pgh.pa.us>; +Cc: pgsql-hackers@lists.postgresql.org
On 2020-Jul-09, Alvaro Herrera wrote:
> I have a moment now, let me have a go at it. I agree with deleting the
> message. I think I'll keep the comment, slightly reworded:
>
> /*
> * Placeholder tuples only appear during unfinished summarization, and we
> * hold SUE lock, so this function cannot run concurrently with
> * that. Any placeholder tuples that exist must be leftovers from a
> * crashed or aborted summarization; remove them silently.
> */
Pushed to all branches.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
^ permalink raw reply [nested|flat] 5+ messages in thread
end of thread, other threads:[~2020-07-10 00:22 UTC | newest]
Thread overview: 5+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2020-06-30 16:24 Intermittent BRIN failures on hyrax and lousyjack Tom Lane <tgl@sss.pgh.pa.us>
2020-07-01 03:28 ` Alvaro Herrera <alvherre@2ndquadrant.com>
2020-07-09 22:46 ` Tom Lane <tgl@sss.pgh.pa.us>
2020-07-09 22:55 ` Alvaro Herrera <alvherre@2ndquadrant.com>
2020-07-10 00:22 ` Alvaro Herrera <alvherre@2ndquadrant.com>
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