I've got some questions regarding a "good" HA Setup for shinken with realms.

The situation:

- Location Office, Server A (Reactionner, Scheduler, Poller, Receiver, Broker), the Server B has the same Services as spare
- Location Datacenter, Servers C (Scheduler, Poller, Receiver) the Server D has the same Services as spare

We've got 3 Datacenter with two Shinken Server and 2 Locations with 1 Shinken Server. Also we've got 10 Shinken Poller with Scheduler, Poller and Receiver.

We are using Realms for configuration, looks fine and works. :-)

If I understood the HA Concept from Shinken right, I need a "Retention DB" for the Scheduler (holds the State, ACK's,Downtimes, etc.). I think MongoDB is a good Choice (I hope! ;-) ). And, if the Scheduler for a Location dies, the standby admin kills me if there are many, many SMS regarding disabled or acknolegded services. ;-)

The MongoDB Wiki says that "old Master-Slave Concept" is deprecated and I may use "Replica Sets". For Replica Sets I need two Members and a Mongo Arbiter OR at least 3 Members. I have for every pair of poller two servers.

Is it correct to use a big MongoDB with 10 Members for the retention? Or should I use an other database for retention?
I think MongoDB is nice, because the Replica Sets looks nice and the Mongos manage the write requests etc..

Well, the real question:

Is there anybody with a smiliar setup? What are you using?

Thanks for help or reading. :-)