[Dovecot] director directing to wrong server (sometimes)

[Angel L. Mateo]

Hello,

	I have discovered a strange behaviour with director proxying...

	I have a user, its assigned server is 155.54.211.164. The problem is 
that I don't know why director sent him yesterday to a different server, 
because my server was up all the time. Moreover, I'm using poolmon in 
director servers to check availability of final servers and it didn't 
report any problem with the server.

	I have two load balanced director servers. Logs at these servers are:

* logs directing him to the correct backend server
Jun 28 08:38:18 myotis42 dovecot: auth: Debug: master in: 
PASS#0111#011<user>@um.es#011service=lmtp#011lip=155.54.211.185#011lport=24#011rip=155.54.212.168#011rport=52255
Jun 28 08:38:18 myotis42 dovecot: auth: Debug: 
static(<user>,155.54.212.168): lookup
Jun 28 08:38:18 myotis42 dovecot: auth: Debug: master out: 
PASS#0111#011user=<user>#011proxy#011proxy_timeout=150
Jun 28 08:38:18 myotis42 dovecot: lmtp(15889): Debug: auth input: 
user=<user> proxy proxy_timeout=150 host=155.54.211.164 proxy_refresh=450
Jun 28 08:39:59 myotis42 dovecot: auth: Debug: master in: 
PASS#01118#011<user>@um.es#011service=lmtp#011lip=155.54.211.185#011lport=24#011rip=155.54.212.166#011rport=40008
Jun 28 08:39:59 myotis42 dovecot: auth: Debug: 
static(<user>,155.54.212.166): lookup
Jun 28 08:39:59 myotis42 dovecot: auth: Debug: master out: 
PASS#01118#011user=<user>#011proxy#011proxy_timeout=150
Jun 28 08:39:59 myotis42 dovecot: lmtp(15361): Debug: auth input: 
user=<user> proxy proxy_timeout=150 host=155.54.211.164 proxy_refresh=450

* now, the other director server sends him to an incorrect backend server
Jun 28 09:01:12 myotis41 dovecot: auth: Debug: 
static(<user>,155.54.66.38): lookup
Jun 28 09:01:12 myotis41 dovecot: auth: Debug: 
static(<user>,155.54.66.38): Allowing any password
Jun 28 09:01:12 myotis41 dovecot: auth: Debug: client out: 
OK#01134556#011user=<user>#011proxy#011proxy_timeout=150#011pass=<hidden>
Jun 28 09:01:12 myotis41 dovecot: auth: Debug: 
static(<user>,155.54.66.38): lookup
Jun 28 09:01:12 myotis41 dovecot: auth: Debug: 
static(<user>,155.54.66.38): Allowing any password
Jun 28 09:01:12 myotis41 dovecot: auth: Debug: client out: 
OK#01152763#011user=<user>#011proxy#011proxy_timeout=150#011pass=<hidden>
Jun 28 09:01:12 myotis41 dovecot: imap-login: proxy(<user>): started 
proxying to 155.54.211.162:143: user=<<user>>, method=PLAIN, 
rip=155.54.66.38, lip=155.54.211.186
Jun 28 09:01:12 myotis41 dovecot: imap-login: proxy(<user>): started 
proxying to 155.54.211.162:143: user=<<user>>, method=PLAIN, 
rip=155.54.66.38, lip=155.54.211.186
Jun 28 09:01:13 myotis41 dovecot: auth: Debug: 
static(<user>,155.54.66.38): lookup
Jun 28 09:01:13 myotis41 dovecot: auth: Debug: 
static(<user>,155.54.66.38): Allowing any password

* Now, the first director sends him to the incorrect one too
Jun 28 09:33:50 myotis42 dovecot: auth: Debug: master in: 
PASS#01132#011<user>@um.es#011service=lmtp#011lip=155.54.211.185#011lport=24#011rip=155.54.212.168#011rport=46830
Jun 28 09:33:50 myotis42 dovecot: auth: Debug: 
static(<user>,155.54.212.168): lookup
Jun 28 09:33:50 myotis42 dovecot: auth: Debug: master out: 
PASS#01132#011user=<user>#011proxy#011proxy_timeout=150
Jun 28 09:33:50 myotis42 dovecot: lmtp(17284): Debug: auth input: 
user=<user> proxy proxy_timeout=150 host=155.54.211.162 proxy_refresh=450

	I haven't found any error log for the correct backend server between 
the correct redirection and the incorrect one. In fact, I have lot of 
logs of other users directed to it, and logs of the same director 
directing connections to the correct server.

-- 
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