[Dovecot] lmtp performance

[Juan Carlos Sanchez]

A particular reply (not to the list) has told me to try:

"
Add to service lmtp:
process_min_avail = 20
"

And yes, it works (unless for me), so I want to share it with everybody.

Have not exactly measured performance but this morning have seen over 
1400 messages/minute with lmtp under heavy load.


What the "process_min_avail = 20" in service lmtp (or anywhere else) 
exactly imply? cannot find a reference in wiki2 . I suppose it means 
than 20 lmtp processes are always open waiting for new connections and 
so reducing startup latency, isn't it?

Thank you.

>
> On Mon, Oct 17, 2011 at 6:06 AM, Juan Carlos Sanchez 
> <juancarlos.sanchez at upm.es <mailto:juancarlos.sanchez at upm.es>> wrote:
>
>     Hello:
>
>     In the process of migration from version 1.2 to 2.0 have tried to
>     use lmtp instead of lda as delivery agent.
>
>     But unfortunately througput we get is poor with lmtp compared to lda.
>     In peak times with lda we are able to deliver over 1800
>     messages/minute (high I/O but not affecting service) but if we
>     switch to lmtp cannot deliver more than 300 mess/minute (very low
>     I/O).
>
>     This is enough for normal work but low under heavy load
>     (distribution lists messages sometimes stay queued for 4 hours
>     before deliver).
>
>     We have arround 50000 boxes and use postfix as MTA
>
>     How to increase lmtp performance?
>
>
>     dovecot config for lda and lmtp:
>
>     protocol lda {
>      auth_socket_path = /usr/local/var/run/dovecot/auth-master
>      info_log_path = /var/log/mail/dovecot_deliver.log
>      log_path = /var/log/mail/dovecot_deliver.log
>      mail_plugins = quota sieve zlib
>      postmaster_address = postmaster at upm.es <mailto:postmaster at upm.es>
>      sendmail_path = /usr/lib/sendmail
>     }
>
>     protocol lmtp {
>      info_log_path = /var/log/mail/dovecot_deliver.log
>      log_path = /var/log/mail/dovecot_deliver.log
>      mail_plugins = quota sieve zlib
>      postmaster_address = postmaster at upm.es <mailto:postmaster at upm.es>
>      sendmail_path = /usr/lib/sendmail
>     }
>
>     In postfix I have:
>
>     mailbox_transport = lmtp:unix:private/dovecot-lmtp
>
>
>
>     Thanks in advance.
>
>     -- 
>
>     ------------------------------------------------------
>     Juan Carlos Sanchez Hernandez
>     Universidad Politecnica de Madrid
>     ------------------------------------------------------
>
>
>

-- 

------------------------------------------------------
Juan Carlos Sanchez Hernandez
Universidad Politecnica de Madrid
------------------------------------------------------