At 09:01 PM 1/30/2007, Curtis Maloney wrote:

Nate wrote:

...

Perhaps another test i'll run, just to compare apples to apples tomorrow would be to use a memory index with dovecot as well, and see if that drops the I/O load to the same as when tpop3d is running.

Speaking of "Apples to Apples", you might want to try with INDEX=MEMORY on Dovecot, see how that fares.

If your users are only POP3 and download all messages at once, not keeping mail on the server, you can (iirc) disable indexing altogether, since it's a wasted effort.

That test was on my list to try out today. I ran the test, and performance was severely degraded. Upon every new login, the entire index was rebuilt. So with any login it takes the full ~30 seconds to rebuild the index on a 17000 email user.

I've confirmed also that tpop3d is doing no indexing whatsoever on disk. It isn't even compiled with that option. So it seems it is probably disk caching which is assisting tpop3d with returning a 2nd login (within a few minutes) so quickly.

I wish it were the case that all users downloaded messages, but it seems all too often users click the 'leave messages on server', and never expire them. We have quite a few users (thousands probably) in that condition. We occasionally delete old stuff. Did I hear about an expire plugin upcoming? That would be useful.

• Nate