Re: [Exim] Our Exim server gets overloaded and starts sendin…

On Mon, 7 Jun 2004 22:44:15 +0200, Fyodorov, Andrey FTL wrote:
> We have a couple of Exim 3.36 #8 gateways for inbound and outbound mail.

That's a bad start ... most people here switched to Exim 4.x years ago (well
it feels like it anyway).

> Lately, toward the middle of the day when the load gets high, remote
> servers receive response 554 from at least one of the Exim servers causing
> them to bounce mail.

Try setting the 'queue_only_load' setting in the configuration file. And
read every mention of 'load' in the Exim3 docs.

> We can also see that when the server is loaded, idle CPU is 0.0% for a
> long time (yet when we add all the CPU utilization numbers shown in top,
> they don't add up to 100%).

They won't. Sometimes the kernel needs some CPU to itself.

> Anyway, why is Exim sending a permanent failure response 554 causing an
> NDR instead of a temporary failure 4xx? Is there a way to change it?
>
> Also is it Exim doing this or could it be Trend or SpamAssassin sending
> the response?

Is Trend listening for mail all by itself ? If so, then that's where the 554
is coming from. If not, then you've probably done something weird with Exim
or discovered a bug.

> For now I think we will lower the max number of SMTP connections to
> prevent the Exim servers from getting overloaded.

I think you're going to have to do more than that. At least upgrade to
Exim4, and probably spend some time thinking about how to handle the load.
Are you using spamd ? Is there a daemonised version of Trend you can use ?

--
Mike Meredith, Senior Informatics Officer
University of Portsmouth: Hostmaster, Postmaster and Security
Naturally, I started with "No!" because I'm always in default denial ;)
-- Paul D. Robertson in firewall wizards