From: Jerry Sievers <gsievers19@comcast.net>
To: Rui DeSousa <rui.desousa@icloud.com>
Cc: Jerry Sievers <gsievers19@comcast.net>,  pgsql-admin@postgresql.org
Subject: Re: pg_rewind: confused about recovery.conf/restore_command
References: <87fu7khohy.fsf@jsievers.enova.com>
	<6EFCAFA0-3555-4F44-A059-3361586984D4@icloud.com>
Date: Fri, 05 Jan 2018 13:12:37 -0600
In-Reply-To: <6EFCAFA0-3555-4F44-A059-3361586984D4@icloud.com> (Rui DeSousa's
	message of "Fri, 05 Jan 2018 09:55:40 -0500")
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Rui DeSousa <rui.desousa@icloud.com> writes:

> Hi Jerry,
>
> That has been my experience as well; pg_rewind does not fetch the WAL
> files.

Hmmm, just prior to my email here last night was my 2nd attempt, taking
a few hours of r/d time to eventually conclude that I was
misunderstanding the docs :-)

A few mentions of recovery.conf in the docs themselves plus what I found
searching Google certainly left me with the impression that pg_rewind
itself knows how to try using a restore_command if found in a
recovery.conf file of the target system to fetch WALs.


> You can use following parameter to keep the most recent logs; i.e. a
> couple of hours worth.  That will allow pg_rewind to work during that

Yup this is obvious and I tested same with OK results.

> time frame =E2=80=94  If it is still missing a WAL file or two you can
> manually copy them over in a pinch.

Yes and in fact I used my restore_command to do so.

>
>  wal_keep_segments=20
>
>
> p.s. I switched to using ZFS snapshots instead.

Oh, my site is quite familiar with FS or SAN/array snapshots and we use
them all the time.

Just felt like pg_rewind looked like something we should try.

I'll wait to see if others can shed more light on this.

Thanks


>
>

--=20
Jerry Sievers
Postgres DBA/Development Consulting
e: postgres.consulting@comcast.net
p: 312.241.7800