Re: [Exim] How to invoke queue runners the right way

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Auteur: Philip Hazel
Datum:  
Aan: Marc Haber
CC: Exim-users
Onderwerp: Re: [Exim] How to invoke queue runners the right way
On Tue, 29 Apr 2003, Marc Haber wrote:

> I will probably change all -q to -qq on my systems, and the Debian
> exim 4 package will probably migrate as well.
>
> This will happen unless somebody on this list objects with a reason.


I do not think you should use -qq for "normal" queue runs. Specifically,
I *definitely* do not think you should use it as default in the Debian (or
any other "standard") packaging of Exim.

Reason: In a "normal" configuration, Exim tries to deliver each message
when it receives it. If it fails (and the recipient is remote), it
remembers which messages are waiting for which hosts in its hints data.
So when it next successfully delivers to one of those hosts, it already
knows which messages to push down the same connection.

If you run a -qq queue runner, it routes every message on the queue, and
sets up the hints file. Then it runs a normal queue run. This is a waste
of resources in most environments, as I hope you can see. Also, for a
large queue, it will take quite a while before it starts delivering.

-qq is useful when the messages on the queue have NOT previously been
attempted, because in that case, Exim has not previously routed them.
This is for special-case use, such as sites that usue queue_only, or
other ways of putting messages on the queue without routing them. One
common case is dial-up hosts that are off-line (I think -qq was invented
for them, come to think of it).

Please do not use blindly replace -q with -qq. It is not a good idea.


--
Philip Hazel            University of Cambridge Computing Service,
ph10@???      Cambridge, England. Phone: +44 1223 334714.