pg.ddx.io pgsql-hackers@postgresql.org mailing list archive help / color / mirror / Atom feed From: Tomas Vondra <tomas.vondra@enterprisedb.com>
To: Amit Kapila <amit.kapila16@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: long-standing data loss bug in initial sync of logical replication
Date: Mon, 24 Jun 2024 16:36:04 +0200
Message-ID: <571f7387-edfa-4733-a335-ccce7ce01574@enterprisedb.com> (raw )
In-Reply-To: <CAA4eK1+W_9zQtaXX4fsrHDrLOZyoFheeLo6ExQX-U6EPGTAqEA@mail.gmail.com >
References: <de52b282-1166-1180-45a2-8d8917ca74c6@enterprisedb.com >
<20231118015443.sfxfbr4eqolxbmjc@awork3.anarazel.de >
<20231118025445.crhaeeuvoe2g5dv6@awork3.anarazel.de >
<49958b83-009a-9360-2969-ea42cd15fff7@enterprisedb.com >
<20231118181257.qtebsnkrzj3icg36@awork3.anarazel.de >
<3c5ad91c-330a-0c5a-974a-da3801ffc18b@enterprisedb.com >
<20231118210519.yborkczu2aln6zdd@awork3.anarazel.de >
<5cc4bbc8-b2ad-3e6e-9878-cef8ddde8ffe@enterprisedb.com >
<20231119021830.d6t6aaxtrkpn743y@awork3.anarazel.de >
<CAA4eK1+W_9zQtaXX4fsrHDrLOZyoFheeLo6ExQX-U6EPGTAqEA@mail.gmail.com >
On 6/24/24 12:54, Amit Kapila wrote:
> ...
>>
>>>> I'm not sure there are any cases where using SRE instead of AE would cause
>>>> problems for logical decoding, but it seems very hard to prove. I'd be very
>>>> surprised if just using SRE would not lead to corrupted cache contents in some
>>>> situations. The cases where a lower lock level is ok are ones where we just
>>>> don't care that the cache is coherent in that moment.
>>
>>> Are you saying it might break cases that are not corrupted now? How
>>> could obtaining a stronger lock have such effect?
>>
>> No, I mean that I don't know if using SRE instead of AE would have negative
>> consequences for logical decoding. I.e. whether, from a logical decoding POV,
>> it'd suffice to increase the lock level to just SRE instead of AE.
>>
>> Since I don't see how it'd be correct otherwise, it's kind of a moot question.
>>
>
> We lost track of this thread and the bug is still open. IIUC, the
> conclusion is to use SRE in OpenTableList() to fix the reported issue.
> Andres, Tomas, please let me know if my understanding is wrong,
> otherwise, let's proceed and fix this issue.
>
It's in the commitfest [https://commitfest.postgresql.org/48/4766/ ] so I
don't think we 'lost track' of it, but it's true we haven't done much
progress recently.
regards
--
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
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To: pgsql-hackers@postgresql.org
Cc: tomas.vondra@enterprisedb.com, amit.kapila16@gmail.com, andres@anarazel.de, pgsql-hackers@lists.postgresql.org
Subject: Re: long-standing data loss bug in initial sync of logical replication
In-Reply-To: <571f7387-edfa-4733-a335-ccce7ce01574@enterprisedb.com>
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