Julian Field mailscanner at ecs.soton.ac.uk
Mon Dec 16 16:53:41 GMT 2002

At 16:33 16/12/2002, you wrote:
>Normally it uses near 900meg+ of ram (I think there might be a mem leak in
>mailscanner, not 100% sure tho)

Each of the processes will get pretty big. Mine often go over 90Mb for each
process. It will use pretty much all the RAM you give it. The possibility
of resource leaks in Perl is one of the reasons that the child processes
restart themselves every few hours.

>  and it handles mail very well.
>I have noticed that when the incoming queue builds up past a certain point,
>it just keeps on going and doesn't catch up.  I have cron scripts setup to
>stop accepting mail once the mqueue.in hits 5000 and doesn't start accepting
>until it drops below 4500.  For whatever reason, once I stop accepting
>messages, the queue drops down several thousand even though I start
>accepting mail again at 4500msgs.

It takes a while to read the entire mqueue.in and sort it by date. If the
queue gets really big, it could end up trying to spend all its time
reading+sorting the queue. Slower CPU's would obviously suffer the problem
worse. Unfortunately you can't get away with not sorting the queue as
otherwise messages will be delivered in the wrong order.

I'll add this to the list of things to look at.

>This behavior is similar on my other 2 boxes, they are not as fast as this
>so they seem to suffer a bit more.
>Does anyone have any suggestions or tips for me ?
>I know I will have to try the new version of mailscanner for sure.
>-----Original Message-----
>From: Julian Field [mailto:mailscanner at ECS.SOTON.AC.UK]
>Sent: Monday, December 16, 2002 11:21 AM
>Subject: Re: RamDisk
>At 15:40 16/12/2002, you wrote:
> >I had an idea earlier about possibly using some sort of ramdisk to
> >handle the mailscanning and mailq items.
> >
> >Have any tests on this type of setup been ran or am I the visionary in
> >this area.
> >
> >I know my mail servers ( I have a cluster of 3 right now ) handle a LOT
> >of mail and I'm looking for ways to help the load and to deliver mail
> >quicker.
> >
> >Any ideas?
>I'm expecting a *very fast* new server tomorrow, I have a load of speed
>tests in mind for it, including this. What sort of ram disk are you
>considering, tmpfs? I must confess I have never set up a ramdisk on a Linux
>box, but I expect it's all pretty obvious.
>Julian Field
>MailScanner thanks transtec Computers for their support

Julian Field
MailScanner thanks transtec Computers for their support

More information about the MailScanner mailing list