dovecot and ldap

Hi Sorry for my question...

I use dovecot+ldap

How realy works (in dovecot-2.2.x ) lists of LDAP hosts to use ?

------ dovecot.conf ----

hosts = ldap.domain.pl:389 ldap-slave.domain.pl:389 #uris =

This is simpe HA ? I mean if ldap.domain.pl have problem another request go to ldap-slave.domain.pl ?