[Dovecot] Performance, dovecot vs tpop3d
Nate
nm_list at visp.net
Wed Jan 31 02:36:06 UTC 2007
At 06:07 PM 1/30/2007, Kenny Dail wrote:
>I'm curious about your setup, what are the times when you do that with tpop3d?
>17K messages makes for a huge maildir, what OS, filesystem, and how is
>it attached?
I just ran the test on tpop3d, it's a production server, so naturally
being early evening the server load is much higher right now, so the
#'s are a bit off from the earlier testing times.
tpop3d takes ~60 seconds to build the index (right now, dovecot takes
about the same). each connection afterwards returns instant
results. I'll do more thorough testing tomorrow when load is down.
The machine is a 1.6ghz Athlon
512mb ram (swap is never dipped into)
Local reiserfs filesystem
linux software raid-1 using 2 disks
disks are sata 7200 rpm seagate enterprise
tpop3d is not configured to store the index on disk, so apparently it
does it all in memory; however, oddly enough, a restart doesn't slow
down the next login so it must have a cache file somewhere i'm
overlooking. it's late and i'll check it out tomorrow.
One significant difference I just noticed between tpop3d and dovecot,
is tpop3d scans the directory and builds it's index directly after
the password is verified and before any commands can be
issues. Dovecot begins building at the same time; however, allows
commands. A LIST command in dovecot will not output results until
the index rebuild is complete. I don't think this has any impact on
performance server-side, but might prompt something different to
happen client side. Unsure.
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.
More information about the dovecot
mailing list