[Dovecot] Restarting dovecot-auth stops authentication

[Attila Nagy]

Hi,

The Dovecot wiki states that Dovecot's master restarts all died 
processes, which is good for availability. But when I kill dovecot/auth 
(to simulate an error condition which happened on a machine), the 
authentication fails with:
Nov 16 14:32:40 be dovecot: imap: Error: net_connect_unix(auth-master) 
failed: No such file or directory

It seems -albeit it gets restarted- dovecot/auth doesn't re-create its 
socket file.
Before:
# ls /var/run/dovecot/
anvil                   auth-worker             doveadm-server
anvil-auth-penalty      config                  dovecot.conf
auth-client             dict                    empty
auth-login              director-admin          lmtp
auth-master             director-userdb         login
auth-userdb             dns-client              master.pid
# ps auwx | grep dovecot/auth
dovecot   87455  0.0  0.0 20024  3832  ??  S     2:34PM   0:00.01 
dovecot/auth
# rm /var/run/dovecot/auth-master; kill 87455
# ps auwx | grep dovecot/auth
dovecot   88815  0.0  0.0 20024  3776  ??  S     2:36PM   0:00.01 
dovecot/auth
# ls /var/run/dovecot/
anvil                   config                  dovecot.conf
anvil-auth-penalty      dict                    empty
auth-client             director-admin          lmtp
auth-login              director-userdb         login
auth-userdb             dns-client              master.pid
auth-worker             doveadm-server

I've deleted the auth-master socket because if I don't, you can't see 
that it's not re-created. :)

Is this a normal behaviour? I understand that killing dovecot/auth is 
not, but Dovecot could survive this easily, if recreating and re-using 
the new socket file would work. And loosing dovecot/auth happens 
sometimes (I don't yet now why).

Thanks,