From: yamt@mwd.biglobe.ne.jp
To: drkp@csail.mit.edu
Cc: pgsql-hackers@postgresql.org
Cc: Kevin.Grittner@wicourts.gov
Cc: heikki.linnakangas@enterprisedb.com
Subject: Re: SSI bug?
Date: Mon, 11 Apr 2011 03:57:19 +0000 (UTC)
Message-ID: <20110411035719.4839E19CF5D@mail.netbsd.org> (raw)
In-Reply-To: <20110407020210.D851019CF0A@mail.netbsd.org>
References: <20110407020210.D851019CF0A@mail.netbsd.org>
hi,
> hi,
>
>> I think I see what is going on now. We are sometimes failing to set the
>> commitSeqNo correctly on the lock. In particular, if a lock assigned to
>> OldCommittedSxact is marked with InvalidSerCommitNo, it will never be
>> cleared.
>>
>> The attached patch corrects this:
>> TransferPredicateLocksToNewTarget should initialize a new lock
>> entry's commitSeqNo to that of the old one being transferred, or take
>> the minimum commitSeqNo if it is merging two lock entries.
>>
>> Also, CreatePredicateLock should initialize commitSeqNo for to
>> InvalidSerCommitSeqNo instead of to 0. (I don't think using 0 would
>> actually affect anything, but we should be consistent.)
>>
>> I also added a couple of assertions I used to track this down: a
>> lock's commitSeqNo should never be zero, and it should be
>> InvalidSerCommitSeqNo if and only if the lock is not held by
>> OldCommittedSxact.
>>
>> Takashi, does this patch fix your problem with leaked SIReadLocks?
>
> i'm currently running bf6848bc8c82e82f857d48185554bc3e6dcf1013 with this
> patch applied. i haven't seen the symptom yet. i'll keep it running for
> a while.
i haven't seen the symptom since them. so i guess it was fixed by
your patch. thanks!
YAMAMOTO Takashi
>
> btw, i've noticed the following message in the server log. is it normal?
>
> LOG: could not truncate directory "pg_serial": apparent wraparound
>
> YAMAMOTO Takashi
>
>>
>> Dan
>>
>>
>> --
>> Dan R. K. Ports MIT CSAIL http://drkp.net/
>
> --
> Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-hackers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: yamt@mwd.biglobe.ne.jp, drkp@csail.mit.edu, Kevin.Grittner@wicourts.gov, heikki.linnakangas@enterprisedb.com
Subject: Re: SSI bug?
In-Reply-To: <20110411035719.4839E19CF5D@mail.netbsd.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox