Need some advice on which replication technology to choose? Please find a network diagram at the following URL for clarity:
A Brief Synopsis:
I need to deploy a web application based on PHP and MySQL across Geographically spread data centres. Each Data Centre will have multiple nodes and the load balancing will be done by a HA Proxy Server within the DC. All nodes within the DC needs to be replicated in Real Time and nodes across DCs need to be replicated in Real Time as well.
When an end user fires a DNS query, the anycast DNS servers will lookup the requestor IP and then route the user to the geographically closest DC. The DNS servers will also manage a DNS level Fail Over in case the HA Proxy Server in any of the DCs goes down. In case an additional HA proxy server is deployed per DC for HA, then the DNS will also do load balancing between the 2 HA proxy servers.
I am stumped with which replication technology to choose. I considered DRBD but then that allows replication between 2 nodes only. DRBD 9 allows multi-node replication however that is yet in pre-release phase. Gluster FS will achieve HA however the Geo Targetting will not work. RSync and Unison are completely out of the equation as they are not real-time.
Thanks and regards,