From: | Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com> |
---|---|
To: | chenhj <chjischj(at)163(dot)com>, pgsql-hackers(at)lists(dot)postgresql(dot)org |
Subject: | Re: could not access status of transaction |
Date: | 2019-01-20 16:19:55 |
Message-ID: | cca621ea-0e93-4515-1266-f21bcba5ae65@2ndquadrant.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On 1/20/19 5:07 PM, chenhj wrote:
> In our PG 10.2(CentOS 7.3) database, the following error is reported when querying a table. We have already restored the production data through backup, but i want to confirm what may be the reason and how to avoid it in the future.
>
> lma=# select count(*) from bi_dm.tdm_ttk_site_on_way_rt;
> ERROR: could not access status of transaction 3250922107
> DETAIL: Could not open file "pg_xact/0C1C": No such file or directory.
>
> Here are some related information
>
> The CLOG files in pg_xact diractory is as follow:
>
> 0C4A(Last update date: 2018/12/29)
> ...
> 0D09(Last update date: 2019/01/13)
>
Yes, that very much looks like a data corruption, probably due to
truncating the clog too early or something like that.
> ...
>
> A similar problem has been reported in 9.0, but there is no reason to mention it.
>
> https://www.postgresql.org/message-id/flat/1300970362.2349.27.camel%40stevie
>
The symptoms are the same, but that's far from sufficient to conclude
it's the same root cause.
> Currently I suspect that it may be the same problem as the bug below. is it possible?
>
> The bug will cause some sessions to cache the wrong relfrozenxid of the table. The session that may call vac_truncate_clog() will clean up the clog after the actual relfrozenxid due to reading the wrong relfrozenxid.
>
> https://www.postgresql.org/message-id/flat/20180809161148.GB22623%40momjian.us#a7cc4d41464064b7752a5574eb74a06d
>
Maybe. But it'll be hard to confirm it's what happened. It also shows
why it's important to keep up with minor updates (you're running 10.3,
which is almost 1 year old).
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
From | Date | Subject | |
---|---|---|---|
Next Message | Dave Cramer | 2019-01-20 16:40:19 | Re: Reviving the "Stopping logical replication protocol" patch from Vladimir Gordichuk |
Previous Message | chenhj | 2019-01-20 16:07:01 | could not access status of transaction |