Patent ID: 6928580

Claim:
A distributed data center system protocol comprising: providing a client having a failure detector and a plurality of data centers each including a plurality of database servers; selecting one of the plurality of data centers to be a primary data center with the other of the plurality of data centers to be a backup data center; selecting one of the plurality of database servers in the primary data center to be a primary database server with the other of the plurality of database servers therein to be a backup database server and the plurality of database servers in the backup data center to be backup database servers; providing communications from the client to the primary database server and the backup database servers; selecting one of the backup database servers as a new primary database server when one of the backup database servers detects a failure of the primary database server; and when the primary database server receives a message from the client to start a new transaction, checking whether the primary database server has already executed another transaction corresponding to the new transaction to ensure that a job generates one committed transaction per database.