Re: LDBM or BDB ?

[Tony Earnshaw <tonye@billy.demon.nl>]

fre, 02.01.2004 kl. 13.07 skrev Ignacio Coupeau:

> > Can anyone give me some reasons to switch from ldbm to Berkeley bdb for
> > LDAP backend? I had such problems getting LDAP to compile with BDB that
> > I gave up on it until recently. Now I don't know if it is worth the
> > effort to recompile all databases to BDB or leave as is. I have roughly
> > 2000 accounts 3 slave LDAP directories and 1 master. These are used
> > primarily for Samba authentication.
> 
> I recommend you stay a while with ldbm; samba wrotes very few in the 
> ldap, so the ldbm may be OK (we have about +29.000 accounts and runs as 
> a charm).

I asked the same question as Kent when I started with Openldap in 2002.
The general answer was, that if there was much writing, ldbm files "got
full of holes" - became steadily sparser. I checked, and it was true;
therefore I went over to BDB. I did experience frequent trouble with
corruption though; db_recover always, always fixed it.

> The DBD requires a careful tunning, and may be a pain if you don't have 
> some experience (look the list :).

Definitely true for 4.0 (extinct, now) and 4.1; but it seems though
4.2(.52 in my case) might be a whole lot better.

Others - though not everyone - have/has experienced rapid performance
degeneration with BDB 4.1. It'll be interesting to see the general
experience with 4.2. Quanah is the one I always look to for experience
here.

Interesting that Wietse Venema, the IBM-employed Postfix MTA guru, is
said to be disenchanted with BDB (source: developers on the Postfix
mailing list) and has gone over from BDB to btree for databases that are
frequently updated (e.g. the experimental Postfix policy daemon
database).

--Tonni

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