Xavier,
On 7/8/10 1:29 AM, "Xavier Pons" xavier.pons@uib.es wrote:
Yes, we will have two hardware balancers in front of proxies. Thus, the director service will detect failures of backend servers and not forward sessions them? how detects if a backend server it's alive or not?
IIRC, it does not detect failures of backend servers. It's up to you to detect outages and react appropriately.
The folks that sponsored Director development apparently have a monitoring script that removes downed nodes by running something like 'ssh directorhost doveadm director remove backendhost', and then re-adds them when they come back up.
I'm not sure how I'm going to handle this myself, as our monitoring system only checks every 5 minutes, and our existing load balancers check and add/remove nodes every 20 seconds or so. 5 minutes would be a long time to have Dovecot trying to send users to a non-functional server.
The command 'doveadm director status', gives information about status of backend mailservers or of director servers?
Just the backend servers - it shows backend server addresses and how many users they're each assigned, or details on a specific user mapping.
I am not aware of a way to get Dovecot to output the director ring status. That would be nice though, to be able to list the directors and how many connections they're each proxying.
You might read though this thread, which starts here: http://www.dovecot.org/list/dovecot/2010-May/049189.html And continues later here: http://www.dovecot.org/list/dovecot/2010-June/049425.html
-Brad