Comment 12 for bug 8392

Message-ID: <email address hidden>
Date: Tue, 9 Nov 2004 01:37:50 +0100
From: Torsten Landschoff <email address hidden>
To: <email address hidden>
Subject: Re: Bug#272984: slapd: checkpoint directive missed from bdb backend

--vtzGhvizbBRQ85DL
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Hi,=20

On Thu, Oct 21, 2004 at 08:28:09AM -0400, Stephen Frost wrote:
> The bdb backend has 'dbnosync' off by default which means that changes
> should be sync'd to disk immediately. I think you may have a problem
> elsewhere. Did you try to dbrecover? When dbnosync is off, what does
> checkpoint do, exactly? My best guess is that it writes a checkpoint,
> which may mean you don't have to dbrecover but at the same time,
> everything between that checkpoint and the time the machine crashed
> would be lost.
>=20
> This bug isn't 'critical'. It might be normal, maybe.

I've read up on Berkeley DB transactions and it seems to me that it
would make sense to write a checkpoint from time to time. No data should
be lost but in the default configuration slapd only checkpoints the DB
during shutdown which means that reopening the database after a crash=20
(which looks for me like the only reason why slapd would go down short
of a system reboot) will take a lot of time wading through old log
files.

I don't want to mess with the slapd defaults for this small problem
though and I wonder what upstream has to say. AFAICT the checkpoint
directive leads to a massive breakdown of write performance for not that=20
much gain.=20

Greetings

 Torsten

--vtzGhvizbBRQ85DL
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Digital signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)

iD8DBQFBkBFedQgHtVUb5EcRAmK3AJ9ElGWLD9e0GV5AG3uW/o2Keh+K9ACcCojG
sPPCt7fnH5qeBsCW2lAuHUs=
=uWH+
-----END PGP SIGNATURE-----

--vtzGhvizbBRQ85DL--