From: TAKATSUKA Haruka <harukat@sraoss.co.jp>
To: Michael Paquier <michael@paquier.xyz>
Cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #15402: Hot standby server with archive_mode=on keeps initial WAL segments
Date: Wed, 26 Sep 2018 13:36:40 +0900
Message-ID: <20180926133640.99bfbc7ea82f71aa91a02c11@sraoss.co.jp> (raw)
In-Reply-To: <20180926035205.GJ1659@paquier.xyz>
References: <15402-a453c90ed4cf88b2@postgresql.org>
<20180926035205.GJ1659@paquier.xyz>
Hello Michael,
Firstly, I will tell the reproduce steps.
On Wed, 26 Sep 2018 12:52:05 +0900
Michael Paquier <michael@paquier.xyz> wrote:
> On Wed, Sep 26, 2018 at 03:26:50AM +0000, PG Bug reporting form wrote:
> > A hot standby server with “archive_mode = on” keeps initial WAL segment
> > files that copied by pg_basebackup. It shows the following status.
> > 000000010000000000000042 will be kept forever in this case.
>
> How did you find yourself in this situation? Did you take a base backup
> from a primary which had .ready files in it, and those got copied to the
> standby's data folder? We may want to study the possibility of
> filtering things when taking a base backup instead.
I can reproduce it by this steps.
$ pg_basebackup -D data_standby -R -Xs
$ pg_ctl start -D data_standby -o '-p 5433'
$ pgbench -i ; pgbench -i ; pgbench -i
$ psql -c 'checkpoint' ; psql -p 5433 -c 'checkpoint'
$ ls data_standby/pg_wal ; ls data_standby/pg_wal/archive_status/
postgresql.conf:
archive_mode = on
archive_command = 'cp %p /tmp/arc/%f'
max_wal_size = 160MB
There are no .ready files right after pg_basebackup.
It will be generated after the replication starts.
Thnaks,
Haruka Takatsuka
> > Though I understand renaming the .ready to .done manually can clean it,
> > I would like to fix the server code like the following patch.
> > I'd appreciate if you would consider that.
>
> Your patch looks incorrect to me to begin with... What if archive_mode
> is switched from "on" to "always" back-and-forth and there some of the
> past segments which should be archived are not?
> --
> Michael
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To: pgsql-bugs@postgresql.org
Cc: harukat@sraoss.co.jp, michael@paquier.xyz, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #15402: Hot standby server with archive_mode=on keeps initial WAL segments
In-Reply-To: <20180926133640.99bfbc7ea82f71aa91a02c11@sraoss.co.jp>
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