A high availability data store system is provided. The system includes data centers, each data center including a data store, host computers, and application instances executing on the host computers. Each host computer routes client requests to the application instances executing on that host computer based on an internet protocol address. The system further includes a load balancer that establishes a session with a client, the session associating a first application instance with an internet protocol address. The load balancer sends the client requests to the first application instance using the first internet protocol address. The system also includes a name service, the name service operable, when the data center fails, to change the session to associate to a second internet protocol address that routes to a second application instance executing on a host computer in one of the operable data centers.