[Dovecot] LDAPS fault tolerance not working with dovecot

[Nikita Koshikov]

Hello list, 

In my dovecot-ldap.ext I have:

uris = ldaps://host1 ldaps://host2 ldaps://host2

Today host1 hangs and new connections can't be established with mail server. Connected users worked fine (auth_cache_size = 5 k auth_cache_ttl = 15 mins). At this time - host2 and host3 are working fine, but switching to them was not happen. Why ?

In logs I got:
Feb 09 10:20:36 imap-login: Error: Timeout waiting for handshake from auth server. my pid=29932, input bytes=0
Feb 09 10:20:36 imap-login: Error: Timeout waiting for handshake from auth server. my pid=29867, input bytes=0
Feb 09 10:20:37 imap-login: Error: auth: connect(login) failed: Resource temporarily unavailable
Feb 09 10:20:37 imap-login: Error: auth: connect(login) failed: Resource temporarily unavailable
Feb 09 10:20:39 imap-login: Error: Timeout waiting for handshake from auth server. my pid=29943, input bytes=0
Feb 09 10:20:40 imap-login: Error: auth: connect(login) failed: Resource temporarily unavailable

I also tried to set:
hosts = host1:636 host2:636 host3:636

But with above config error log fulls with messages:
Feb 09 10:44:57 auth: Error: LDAP: Connection lost to LDAP server, reconnecting

And none of servers accepted ldaps connection. 

Is someone has a success make ldaps fault tolerance ?