[Dovecot] Dsync replication

[list at airstreamcomm.net]

I have been loosely following discussions dsync replication, but I am 
wondering if this tool still in a testing phase or has it been committed 
as a production part of Dovecot?  I would like to do some testing with 
the protocol to see if it's capable of handling the change rate our mail 
service generates, which has about 23,000 active users.  We are trying 
to find solutions for a two site setup where mail processing is either 
being done at the primary data center A and fails over to a hot standby 
cluster at the secondary data center B, or where both data centers are 
doing active processing.  I have been unable to find documentation on 
dsync replication on the wiki, so if there is any documentation 
available on how to setup dsync replication I would appreciate a nudge 
in the right direction.