From: Bruce Momjian <bruce@momjian.us>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: pgsql-hackers@lists.postgresql.org
Subject: Re: pg_upgrade should truncate/remove its logs before running
Date: Wed, 15 Dec 2021 16:09:16 -0500
Message-ID: <20211215210916.GC4440@momjian.us> (raw)
In-Reply-To: <20211212025017.GN17618@telsasoft.com>
References: <20211212025017.GN17618@telsasoft.com>
On Sat, Dec 11, 2021 at 08:50:17PM -0600, Justin Pryzby wrote:
> I have seen this numerous times but had not dug into it, until now.
>
> If pg_upgrade fails and is re-run, it appends to its logfiles, which is
> confusing since, if it fails again, it then looks like the original error
> recurred and wasn't fixed. The "append" behavior dates back to 717f6d608.
>
> I think it should either truncate the logfiles, or error early if any of the
> files exist. Or it could put all its output files into a newly-created
> subdirectory. Or this message could be output to the per-db logfiles, and not
> just the static ones:
> | "pg_upgrade run on %s".
>
> For the per-db logfiels with OIDs in their name, changing open() from "append"
> mode to truncate mode doesn't work, since they're written to in parallel.
> They have to be removed/truncated in advance.
>
> This is one possible fix. You can test its effect by deliberately breaking one
> of the calls to exec_progs(), like this.
>
> - "\"%s/pg_restore\" %s %s --exit-on-error --verbose "
> + "\"%s/pg_restore\" %s %s --exit-on-error --verboose "
Uh, the database server doesn't erase its logs on crash/failure, so why
should pg_upgrade do that?
--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EDB https://enterprisedb.com
If only the physical world exists, free will is an illusion.
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To: pgsql-hackers@postgresql.org
Cc: bruce@momjian.us, pryzby@telsasoft.com, pgsql-hackers@lists.postgresql.org
Subject: Re: pg_upgrade should truncate/remove its logs before running
In-Reply-To: <20211215210916.GC4440@momjian.us>
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