[imp] imp causes high load ?

[Clive McDowell]

On Tue, 6 Feb 2001 11:27:45 -0500 (EST) serene@home.martnet.com wrote:

> Hello,
> 
> For some time we have been experiencing very high loads that seems to be
> caused by imp.  We are running imap and a small website and basically
> nothing much else.  We had tried to upgrade the apache webserver,
> but it didn't help that much.
> Has anyone ever had a similar experience and are there
> any solutions if in fact the high load is due to imp? 
> 
> 
> here are what we have:
> 
> solaris 2.6
> apache 1.3.17 + mod_ssl-2.8.1 + php-4.0.4pl1 + openssl-0.9.6
> imp 2.2 and horde 1.2

You don't say what imap software you are using on your mail server 
but my guess is that it is some version of UW. Because IMP does not 
use persistent imap connections a new imapd process is spawned and 
closed down each time you perform an imap operation. There is a high 
cpu loading when the imapd process starts up (thereafter it's quite 
efficient but we're not using it in the way in which it was 
originally intended). Your only solutions are to beef up the 
processor power on your mail platform or switch to a lighter weight 
imapd such as courier. We have a similar problem which I have solved 
by restricting access to IMP to off-site connections only but then 
the IMP service here was introduced for just that purpose.

Regards,

Clive McDowell

Information Services
The Queen's University of Belfast