BUG #16159: recovery requests WALs for the next timelines before timeline switch LSN has been reached

pg.ddx.io  pgsql-bugs@postgresql.org mailing list archive  
help / color / mirror / Atom feed

From: PG Bug reporting form <noreply@postgresql.org>
To: pgsql-bugs@lists.postgresql.org
Cc: psuderevsky@gmail.com
Subject: BUG #16159: recovery requests WALs for the next timelines before timeline switch LSN has been reached
Date: Wed, 11 Dec 2019 12:39:20 +0000
Message-ID: <16159-f5a34a3a04dc67e0@postgresql.org> (raw)

The following bug has been logged on the website:

Bug reference:      16159
Logged by:          Pavel Suderevsky
Email address:      psuderevsky@gmail.com
PostgreSQL version: 11.6
Operating system:   CentOS 7.6.1810 (3.10.0-957.el7.x86_64)
Description:        

Reproduced 11.2,11.6.

If PostgreSQL starts recovery and finds a history file for a timeline that
is higher than current one, it will request file with the segment for the
future timeline (that most likely doesn't exist yet) and only then it will
request file with the segment for current timeline. 
If archive is located on remote storage it can take huge time to find that
segments for the future timelines are not exist yet and therefore recovery
can take too long.

Example:

recovery.conf:
>restore_command = 'echo -e "Searching WAL: %f, location: %p";
/usr/bin/pgbackrest --stanza=platform archive-get %f "%p"'
>recovery_target_timeline = 'latest'
>standby_mode = 'on'

Postgres log during startup:
>
> 2019-12-06 07:11:16 CST  LOG:  database system was shut down in recovery
> at 2019-12-06 07:11:08 CST
> Searching WAL: 00000022.history, location: pg_wal/RECOVERYHISTORY
> 2019-12-06 07:11:16 CST  LOG:  restored log file "00000022.history" from
> archive
> Searching WAL: 00000023.history, location: pg_wal/RECOVERYHISTORY
> 2019-12-06 07:11:16 CST  LOG:  entering standby mode
> Searching WAL: 00000022.history, location: pg_wal/RECOVERYHISTORY
> 2019-12-06 07:11:16 CST  LOG:  restored log file "00000022.history" from
> archive
> Searching WAL: 00000022000018C60000003F, location: pg_wal/RECOVERYXLOG
> Searching WAL: 00000021000018C60000003F, location: pg_wal/RECOVERYXLOG
> 2019-12-06 07:11:20 CST  LOG:  restored log file
> "00000021000018C60000003F" from archive
> Searching WAL: 00000021.history, location: pg_wal/RECOVERYHISTORY
> 2019-12-06 07:11:20 CST  LOG:  restored log file "00000021.history" from
> archive
> Searching WAL: 00000022000018BF0000001B, location: pg_wal/RECOVERYXLOG
> Searching WAL: 00000021000018BF0000001B, location: pg_wal/RECOVERYXLOG
> 2019-12-06 07:11:27 CST  LOG:  restored log file
> "00000021000018BF0000001B" from archive
> 2019-12-06 07:11:27 CST  LOG:  redo starts at 18BF/1B311260
> Searching WAL: 00000022000018BF0000001C, location: pg_wal/RECOVERYXLOG
> Searching WAL: 00000021000018BF0000001C, location: pg_wal/RECOVERYXLOG
> 2019-12-06 07:11:34 CST  LOG:  restored log file
> "00000021000018BF0000001C" from archive
> Searching WAL: 00000022000018BF0000001D, location: pg_wal/RECOVERYXLOG
> Searching WAL: 00000021000018BF0000001D, location: pg_wal/RECOVERYXLOG
> 2019-12-06 07:11:40 CST  LOG:  restored log file
> "00000021000018BF0000001D" from archive
> Searching WAL: 00000022000018BF0000001E, location: pg_wal/RECOVERYXLOG
> Searching WAL: 00000021000018BF0000001E, location: pg_wal/RECOVERYXLOG
> 2019-12-06 07:11:46 CST  LOG:  restored log file
> "00000021000018BF0000001E" from archive
> Searching WAL: 00000022000018BF0000001F, location: pg_wal/RECOVERYXLOG
> Searching WAL: 00000021000018BF0000001F, location: pg_wal/RECOVERYXLOG
> 2019-12-06 07:11:53 CST  LOG:  restored log file
> "00000021000018BF0000001F" from archive

As you can see Postgres tries to restore  00000022* WALs before timeline
switch LSN has been reached while restoring 00000021*.

view thread (3+ messages)  latest in thread

Message-ID: <16159-f5a34a3a04dc67e0@postgresql.org>
Permalink:  ../16159-f5a34a3a04dc67e0@postgresql.org/
Also on:    postgresql.org/message-id/16159-f5a34a3a04dc67e0@postgresql.org

 ·

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-bugs@postgresql.org
  Cc: noreply@postgresql.org, pgsql-bugs@lists.postgresql.org, psuderevsky@gmail.com
  Subject: Re: BUG #16159: recovery requests WALs for the next timelines before timeline switch LSN has been reached
  In-Reply-To: <16159-f5a34a3a04dc67e0@postgresql.org>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox