From: Andres Freund <andres@anarazel.de>
To: Julien Riou <julien.riou@outlook.com>
Cc: pgsql-admin@lists.postgresql.org <pgsql-admin@lists.postgresql.org>
Subject: Re: ERROR: no known snapshots
Date: Sat, 25 Aug 2018 07:43:03 -0700
Message-ID: <20180825144303.2cbtf7fyor7mkpvm@alap3.anarazel.de> (raw)
In-Reply-To: <DB5PR0201MB17507769C5709234B25A409BE2350@DB5PR0201MB1750.eurprd02.prod.outlook.com>
References: <DB5PR0201MB17507769C5709234B25A409BE2350@DB5PR0201MB1750.eurprd02.prod.outlook.com>
On 2018-08-25 07:04:14 +0000, Julien Riou wrote:
> Hello,
>
> We have few highly available clusters with patroni managing PostgreSQL
> 9.6 (pgdg on debian stretch). We use logical decoding with wal2json to
> stream data to a remote platform. On a majority of clusters, it works
> like a charm. But for one, we have the following error right after
> decoding start:
>
> [1353-1] LOG: starting logical decoding for slot "*****"
> [1353-2] DETAIL: streaming transactions committing after 321/292C06F0, reading WAL from 321/28BA9898
> [1354-1] LOG: logical decoding found consistent point at 321/28BA9898
> [1354-2] DETAIL: There are no running transactions.
> [1355-1] ERROR: no known snapshots
> [1355-2] CONTEXT: slot "*****", output plugin "wal2json", in the change callback, associated LSN 321/2A985A30
>
> The only reference of the "no known snapshots" error is in PostgreSQL source
> code:
> https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/access/heap/tuptoaster.c;h=...
>
> Do you know what can cause this error?
Any chance that you're specifying the "include_unchanged_toast" option?
I briefly looked over wal2json (which isn't part of PG) and as far as I
can tell that option simply can't work correctly, and would cause errors
like the above.
Greetings,
Andres Freund
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To: pgsql-admin@postgresql.org
Cc: andres@anarazel.de, julien.riou@outlook.com, pgsql-admin@lists.postgresql.org
Subject: Re: ERROR: no known snapshots
In-Reply-To: <20180825144303.2cbtf7fyor7mkpvm@alap3.anarazel.de>
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