[Dovecot] Problem with lmtp director proxy

[Angel L. Mateo]

Hi,

	I have a timeout problem only when I have heavy load in my system. I 
have two director servers directing to 4 backend servers.

	The problem is when my smtp relays tries to deliver mail to my users 
via lmtp (proxied with director).

	In the smtp logs I have:

Jun 12 11:41:18 xenon13 postfix/lmtp[4248]: 4433E5D5A0: 
to=<myuser at um.es>, relay=pop.um.es[155.54.212.106]:24, delay=31, 
delays=0.41/0.06/0/30, dsn=4.4.0, status=deferred (host 
pop.um.es[155.54.212.106] said: 451 4.4.0 Remote server not answering 
(timeout while waiting for reply to DATA reply) (in reply to end of DATA 
command))

	If I look for this connection in the director servers I have:

Jun 12 11:40:39 myotis41 dovecot: lmtp(6595): Connect from 155.54.212.167
Jun 12 11:40:39 myotis41 dovecot: lmtp(6595): Debug: auth input: 
user=user1 proxy host=155.54.211.163 proxy_refresh=450
Jun 12 11:40:39 myotis41 dovecot: lmtp(6595): Debug: auth input: 
user=user2 proxy host=155.54.211.163 proxy_refresh=450
....  (more users, a total of 34 recipients)
Jun 12 11:40:39 myotis41 dovecot: lmtp(6595): Debug: auth input: 
user=myuser proxy host=155.54.211.164 proxy_refresh=450
...
Jun 12 11:41:09 myotis41 dovecot: lmtp(6595): Disconnect from 
155.54.212.167: Client quit (in reset)

	and in one of the final server (the one for the user in question):

Jun 12 11:40:38 myotis34 dovecot: lmtp(16824): Connect from 155.54.211.186
Jun 12 11:40:38 myotis34 dovecot: lmtp(16824, <user1>): wJ9BD7YM10
+4QQAAG5O5Qg: sieve: 
msgid=<182283367.48.1339494011054.JavaMail.tomcat at sakai-prod4>: stored 
mail into mailbox 'INBOX'
...
Jun 12 11:41:10 myotis34 dovecot: lmtp(16824, <myuser>): wJ9BD7YM10+4QQA
AG5O5Qg: sieve: 
msgid=<182283367.48.1339494011054.JavaMail.tomcat at sakai-prod4>: stored 
mail into mailbox 'INBOX'
...
Jun 12 11:41:11 myotis34 dovecot: lmtp(16824): Disconnect from 
155.54.211.186: Connection closed (in reset)

	So the mail seems to be correctly delivered in about 30 seconds. All my 
postfix timeouts are bigger than this time:

lmtp_connect_timeout = 0s
lmtp_connection_cache_time_limit = 2s
lmtp_connection_reuse_time_limit = 300s
lmtp_data_done_timeout = 600s
lmtp_data_init_timeout = 120s
lmtp_data_xfer_timeout = 180s
lmtp_lhlo_timeout = 300s
lmtp_mail_timeout = 300s
lmtp_pix_workaround_delay_time = 10s
lmtp_pix_workaround_threshold_time = 500s
lmtp_quit_timeout = 300s
lmtp_rcpt_timeout = 300s
lmtp_rset_timeout = 20s
lmtp_sasl_auth_cache_time = 90d
lmtp_starttls_timeout = 300s
lmtp_tls_session_cache_timeout = 3600s
lmtp_xforward_timeout = 300s

	So... why do I have this error?

	As a side effect this mail was delivered twice in the user's  mailbox, 
this is one and the other when postfix retries again.

	Any help? Thank you


-- 
Angel L. Mateo Martínez
Sección de Telemática
Área de Tecnologías de la Información       _o)
y las Comunicaciones Aplicadas (ATICA)      / \\
http://www.um.es/atica                    _(___V
Tfo: 868887590
Fax: 868888337