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

[Michael Lang]

On Wed, 2006-10-04 at 14:25 -0800, Matthew Schumacher wrote:
> 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.

thinking about, what's more complex, using another 'singlepoint of
failure' within your filter (ramdisk, dbbackend, cache,...) or just
using Mimedefang 2.56 which just handles slave requests with one
instance (so your query can be stored for one email in Variables). 

I'm running 2.56 as i additional count RFC ignorant or CountryBases
Scores to Spammassassin Tagging scores from filter_recipient to
filter_end so the request must stay on the instance, but maybe thats a
feature Request for David to be able to select the Queuing/Scheduling
Algorithm within the same Version ? ...

Kind regards
Michael Lang

> 
> schu
> 
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-- 
Michael Lang <michi+mimedefang at relay3.jackal-net.at>