Thread: BUG #8450: pg_basebackup blocks until WAL archiving successful

BUG #8450: pg_basebackup blocks until WAL archiving successful

From
stuart@stuartbishop.net
Date:
The following bug has been logged on the website:

Bug reference:      8450
Logged by:          Stuart Bishop
Email address:      stuart@stuartbishop.net
PostgreSQL version: 9.1.9
Operating system:   all
Description:

Hi.


pg_basebackup blocks until all necessary WAL files have been archived by
archive_command. This can take a few minutes under normal circumstances, and
indefinitely if archive_command is failing.


I would like to be able to disable this check, as I am streaming backups to
a system that can time out my connection if it does not receive new data for
a short while. This makes unattended backups problematic.

Re: BUG #8450: pg_basebackup blocks until WAL archiving successful

From
Heikki Linnakangas
Date:
On 13.09.2013 15:13, stuart@stuartbishop.net wrote:
> pg_basebackup blocks until all necessary WAL files have been archived by
> archive_command. This can take a few minutes under normal circumstances, and
> indefinitely if archive_command is failing.
>
> I would like to be able to disable this check, as I am streaming backups to
> a system that can time out my connection if it does not receive new data for
> a short while. This makes unattended backups problematic.

I can see why you'd want that, but it seems equally problematic to let
pg_basebackup return, when the WAL files haven't been archived yet and
you therefore don't in fact have valid, restorable backup yet. Have you
considered using the --xlog-method=stream option, to include the WAL
files in the backup? That will make your backups somewhat larger, as the
WAL files are included, but in that mode pg_basebackup won't wait for
the archival and the backup will be restorable even if archive_command
is failing.

- Heikki

Re: BUG #8450: pg_basebackup blocks until WAL archiving successful

From
Stuart Bishop
Date:
On Mon, Sep 23, 2013 at 3:33 PM, Heikki Linnakangas

> I can see why you'd want that, but it seems equally problematic to let
> pg_basebackup return, when the WAL files haven't been archived yet and you
> therefore don't in fact have valid, restorable backup yet. Have you
> considered using the --xlog-method=stream option, to include the WAL files
> in the backup? That will make your backups somewhat larger, as the WAL files
> are included, but in that mode pg_basebackup won't wait for the archival and
> the backup will be restorable even if archive_command is failing.

I'm supporting PG 9.1 at the moment so cannot rely on
--xlog-method=stream. I agree that the current behavior is for most
use cases better, and I think that the behavior I want should be
explicitly enabled with an option.


--
Stuart Bishop <stuart@stuartbishop.net>
http://www.stuartbishop.net/