Gerben Wierda:
> Currently, every time haproxy checks if postfix is still alive,
> e.g. on port 587, I see this in my logging:
>
> Jan 28 13:13:20 albus submission/smtpd[97331]: warning: haproxy read: EOF
> Jan 28 13:13:20 albus submission/smtpd[97331]: connect from unknown[unknown]
> Jan 28 13:13:20 albus submission/smtpd[97331]: disconnect from
> unknown[unknown] commands=0/0
That is not a valid health check, it does not even complete the
HaProxxy protocol handshake (that's why it logs "haproxy read:
EOF"). You only verify TCP. Postfix could be comatose and this probe
would not notice.
A proper health check verifies that a service actually responds.
You can find more with "haproxy health check script". For example,
Postfix should reply with a "220" status within 5 seconds.
Wietse
