Topic: Can DBMail work for georedundancy?
I am planning to install iRedmail with SoGo on two new vServers (OpenVZ CentOS 7) which are in different datacenters / different cities.
I do not want to create a setup with a simple MX backup since that would only ensure mail delivery when a server is down and wouldn't help in a critical event where the primary server is lost.
When I replace Dovecot with DBMail from my understanding everything from configuration to mail data incl. attachments should be stored in MariaDB. When I setup a Master-Master sync of MariaDB between the two servers then both servers should contain the full setup and any one server could fail without loosing any functionality.
Since KeepAlived, HAProxy, etc. will not work with geographic redundant locations and the inability to route one ip to both hosts I plan on using cheap DNS round robin. I know DNS RR can have issues when a DNS cache has the IP stored which is down etc., but I am not looking into high performance failover but rather a fully functioning server in the case of a disaster to keep services running within 24 hours max.
So what do you think? Basically there are two questions out there:
- What's the probability of breaking future iRedmail upgrades when switching from the default Dovecot to DBMail?
- Will a Master-Master sync in combination with DNS round robin work with iRedmail and is there really no data left to be synced when DBMail is used except maybe config files?