Haproxy and Dovecot auth

[Giuseppe Civitella]

Hi all,

I'd like to use Haproxy to balance an auth service on a couple of
Dovecot directors to have a redundant sasl service for my Postfix instances.
While I configure the Postfixes to use, as smtpd_sasl_path, a direct
connection to one of the directors I notice no errors.
When I redirect the smtpd_sasl_path through an Haproxy balanced
connection, I receive an error the first time I try to sen an email.
The error is:
SASL PLAIN authentication failed: Connection lost to authentication server
If then I send more emails I receive no errors.
If I do not send emails for a few minutes, the error appears again.

The relevant Haproxy configuration is the following:

listen auth *:12345
      mode tcp
      balance source
      log global
      option tcplog
      option log-health-checks
      stick-table type ip size 200k expire 30m
      stick on src
      default-server inter 1000 fall 3 rise 1
      server dovecot-director01 dovecot-director01:12345 check

Do anyone have an idea about what it's missing?

Thanks a lot
Giuseppe

-- 
Giuseppe Civitella
gcivitella at entermail.it