LDAP: Connection appears to be hanging, reconnecting

[Simon Fraser]

On 16/12/14 16:30, Matthias Egger wrote:

> What happened:
> A few weeks ago one of the LDAPS Servers which is not maintained by us
> has crashed. From that moment on, users could still login to check their
> emails, but they were not able to send any email through postfix (which
> uses smtpd_sasl_type = dovecot)
>
> What i do not understand, is why did dovecot not switch to the second
> configured LDAPS Server? It looks like it retried for ever to reconnect
> to the crashed LDAP Server.

This is speculation, but what has happened to us in the past is that the 
LDAP server stopped responding to queries, but the TCP socket was still 
open for connections. A new TCP connection would be established, but the 
daemon would not be notified of it.

So, depending on precisely how the first LDAP server crashed, it may not 
be the same test as killing the process, but closer to sending it 'kill 
-STOP' (and then 'kill -CONT' afterwards, obviously)

Simon.



-- 
 The Wellcome Trust Sanger Institute is operated by Genome Research 
 Limited, a charity registered in England with number 1021457 and a 
 company registered in England with number 2742969, whose registered 
 office is 215 Euston Road, London, NW1 2BE.