[Mimedefang] LDAP lookup in each function or write the LDAP results to the spool?

[John Scully]

generally speaking, if your working dirs are on ramdisk it is pretty light 
load to write files there.  We use a mysql based mail platform and cache 
information to the working dir to reduce multiple DB hits.

When in the RCPT phase we hit the DB to see if it is a valid recipient etc. 
This DB dip also returns the spam settings for that user, which we write 
(append) to a file in the mimedefang working dir.

Then, if there were any valid recipients we hit DCC, greylist, spamassassin 
etc, score the message, read the spam_settings file back in and process it 
for each user as per their individual settings.

There may be lower overhead solutions, but this is pretty light, and easy to 
implement and debug.

John
----- Original Message ----- 
From: "Matthew Schumacher" <matt.s at aptalaska.net>
To: <mimedefang at lists.roaringpenguin.com>
Sent: Wednesday, October 04, 2006 6:25 PM
Subject: [Mimedefang] LDAP lookup in each function or write the LDAP results 
to the spool?


>
> List,
>
> My mail system is getting pretty complex, we have all sorts of features
> and options and they are all controlled by ldap attributes.  Well, as
> you all know, the ldap record can't be saved between functions as
> mimedefang may not use the same child for the next milter call.  Because
> of this I'm doing a LDAP lookup in almost every filter function, for a
> total of 4 lookups per message.
>
> At this point it seems kinda redundant to me so I started looking at
> other ways to reduce the amount of ldap queries, but the only thing that
> comes to mind is to write the attributes to a LDAP file in the spool
> then look at it instead of sending more queries to the LDAP server.  It
> seems to me that opening/parsing/closing a file (even on a ramsdisk) is
> going to be more expensive because my ldap server does cache the data,
> and because the directory fits in memory, but I'm unsure.
>
> Any thoughts on this?  Anyone else run into this and do some
> benchmarking?  Perhaps it's a wash, but it's something to think about.
>
> schu
>
> _______________________________________________
> NOTE: If there is a disclaimer or other legal boilerplate in the above
> message, it is NULL AND VOID.  You may ignore it.
>
> Visit http://www.mimedefang.org and http://www.roaringpenguin.com
> MIMEDefang mailing list MIMEDefang at lists.roaringpenguin.com
> http://lists.roaringpenguin.com/mailman/listinfo/mimedefang
>
>