multiple mailscanner instances?

[Jim Levie]

On Fri, 2002-09-13 at 19:22, Eric H wrote:
> On Fri, 13 Sep 2002, Jim Levie wrote:
>
> > Yes, it is possible to run more than one instance of MailScanner, but
> > it's a little more complicated. What needs to happen in that case is
> > that Sendmail is configured to drop inbound mail into mqueue.in. Then
> > you need something else that picks up qf/df pairs from the input queue
> > and distributes those to two or more MailScanner work queues. Each of
>
> But that would cost another disk read/write. How exactly is MailScanner
> picking up qf/df pairs from the input queue that it can't cooperate
> with another instance?
>
Julian could provide the best analysis, but a quick read of the code
said to me that it scans the input queue and identifies "Max
Safe|Unsafe" sized batch of messages to process. The header data of
those are written into MailScanners incoming directory
(xxxxxxxxxx.header) and an internal list is constructed. Then it
processes each message in that batch. The original copy of each message
remains in the input queue until processing of that batch is complete.

So running more than one instance on the same input queue and with the
same work dirs isn't going to work, if I read the code correctly. At the
very least you'd get duplicate delivery of at least some messages.

Distributing the input queue to multiple processing queues is cheap,
because it's just a "mv" of the qf/df pair. If you are interested I can
clean up the queue mgmt code and document how I do it on a server that
handles some 150-180K messages a day.
--
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The instructions said to use Windows 98 or better, so I installed RedHat
   Jim Levie                                 email:
jim at entrophy-free.net