[imp] Permformance issue

[Eric Rostetter]

Quoting Andrew Morgan <morgan@orst.edu>:
 
> My personal opinion is that you are better off installing IMP on a
> separate machine.  No matter where you install IMP, it will make an IMAP
> or POP connection to your mail server.  In one case this happens locally
> by connecting to localhost and in the other case it happens across the
> network.

That doesn't mean that localhost vs network access perform equally, or have the
same security.
 
> If for some reason you have a really slow network between the two
> machines, then running it locally would make sense.  Otherwise, I'd rather
> have the extra horsepower of a second machine.

Unless you already have too much horsepower already, and/or cost is a concern.

> IMP, especially using SSL
> connections, does take some horsepower to run, so why not take that load
> off of your mail server.  Let your mail server just handle IMAP/POP
> connections.

To be secure, you would then need ssl for the imap/pop connection, so basically
you've doubled the amount of encryption on your web server now (https and
simap/spop3) and haven't decreased the amount of encryption on the mail
server (roughly, not an exact science here).

> Where possible, I prefer to dedicate servers to separate services rather
> than running it all on one big machine.

I can't disagree with that from a management point of view.  But that is
not the same issue as performance.

For example, when I split my IMP installation from one machine to two,
management became 100% better, but performance died (average request now
takes about twice as long as before).  But we did the split for management
reasons, and we're willing to eat the performance loss.

The performance hit we saw is completely explainable and we knew it would
happen.  But we desired it none-the-less.  Other setups would of course
be different, and hence the outcome different.

> Hope this helps,
> 	Andy

-- 
Eric Rostetter
The Department of Physics
The University of Texas at Austin

"TAD (Technology Attachment Disorder) is an unshakable, impractical devotion
to a brand, platform, product line, or programming language. It's relatively
harmless among the rank and file, but when management is afflicted the damage
can be measured in dollars. It's also contagious -- someone with sufficient
political clout can infect an entire organization."

--"Enterprise Strategies" columnist Tom Yager.