Message-ID: <55439214.6080506@iki.fi>
Date: Fri, 01 May 2015 07:47:48 -0700
From: Heikki Linnakangas <hlinnaka@iki.fi>
Reply-To: hlinnaka@iki.fi
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To: Peter Geoghegan <pg@heroku.com>
CC: Andres Freund <andres@anarazel.de>, Jeff Janes <jeff.janes@gmail.com>,
 Stephen Frost <sfrost@snowman.net>,
 Dean Rasheed <dean.a.rasheed@gmail.com>, Bruce Momjian <bruce@momjian.us>,
 Pg Hackers <pgsql-hackers@postgresql.org>
Subject: Re: INSERT ... ON CONFLICT UPDATE/IGNORE 4.0
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	<553EFF0D.4040903@iki.fi>
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	<5542DE23.6060800@iki.fi>
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On 04/30/2015 11:09 PM, Peter Geoghegan wrote:
> I've been unable to reproduce the unprincipled deadlock using the same
> test case as before. However, the exclusion constraint code now
> livelocks. Here is example output from a stress-testing session:
>
>...
>
> [Fri May  1 04:45:35 2015] normal exit at 1430455535 after 128000
> items processed at count_upsert_exclusion.pl line 192.
> trying 128 clients:
> [Fri May  1 04:45:58 2015] NOTICE:  extension "btree_gist" already
> exists, skipping
> [Fri May  1 04:45:58 2015] init done at count_upsert_exclusion.pl line 106.
>
>
> (I ssh into server, check progress). Then, due to some issue with the
> scheduler or something, progress continues:
>
> [Fri May  1 05:17:57 2015] sum is 462
> [Fri May  1 05:17:57 2015] count is 8904
> [Fri May  1 05:17:58 2015] normal exit at 1430457478 after 128000
> items processed at count_upsert_exclusion.pl line 192.
> trying 128 clients:

Hmm, so it was stuck for half an hour at that point? Why do you think it 
was a livelock?

> This is the same server that I shared credentials with you for. Feel
> free to ssh in and investigate it yourself.

I logged in, but the system seems very unresponsive in general. I just 
started "apt-get install gdb" on it, to investigate what the backends 
are stuck at. It's been running for about 30 minutes now, and I'm still 
waiting...

- Heikki


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