Method and system for data synchronization

A data synchronization method, comprising:

• providing a first server with a synchronizing flag for a data block;
• providing a second server with a master flag and a write flag for the data block;
• synchronizing, by a synchronizing component, data of the data block on the second server with the first server;
• removing the master flag of the data block on the second server and removing the synchronizing flag of the data block on the first server if an error occurs on the second server;
• and
• configuring a master flag and a write flag for the data block on the first server;
• importing a snapshot of the data block to the second server after the second server recovers from the error;
• configuring a synchronizing flag for the data block on the second server;
• synchronizing, by the synchronizing component, data of the data block on the first server to the second server;
• removing the write flag of the data block on the first server when a master status of the second server for the data block is to be restored;
• synchronizing, by the synchronizing component, latest data of the data block on the first server to the second server;
• removing the master flag of the data block on the first server and removing the synchronizing flag of the data block on the second server after the data of the data block on the second server and the data of the data block on the first server are completely synchronized;
• and
• configuring a master flag and a write flag for the data block on the second server and configuring a synchronizing flag for the data block on the first server.

A data synchronization system, comprising:

• a first server;
• a second server;
• a configuring module, configured to generate a master flag and a write flag for the data block on the first server;
• an import module, configured to import a snapshot of the data block to the second server;
• and
• a synchronizing component, configured to synchronize data of the data block on the first server to the second server, wherein:
• the configuring module is further configured to generate a synchronizing flag for the data block on the second server;
• to remove the write flag of the data block on the first server when the data block is to be migrated out of the first server;
• and to remove the master flag of the data block on the first server and remove the synchronizing flag of the data block on the second server after data of the data block on the second server and data of the data block on the first server are completely synchronized, and to generate a master flag and a write flag for the data block on the second server.

A data synchronization system, comprising:

• a first server;
• a second server;
• a configuring module, configured to generate a synchronizing flag for a data block on the first server, and configured to generate a master flag and a write flag for the data block on the second server;
• a synchronizing component, configured to synchronize data of the data block on the second server to the first server;
• and
• an import module, configured to import a snapshot of the data block to the second server after the second server recovers from the error, wherein:
• the configuring module is further configured to remove the master flag of the data block on the second server and remove the synchronizing flag of the data block on the first server if an error occurs on the second server, and generate a master flag and a write flag for the data block on the first server;
• and to generate a synchronizing flag for the data block on the second server after the second server recovers from the error;
• the synchronizing component is further configured to synchronize data of the data block on the first server to the second server after the second server recovers from the error;
• and
• the configuring module is further configured to remove the write flag of the data block on the first server when a master status of the second server for the data block is to be restored;
• and to remove the master flag of the data block on the first server and remove the synchronizing flag of the data block on the second server after data of the data block on the second server and data of the data block on the first server are completely synchronized, and generate a master flag and a write flag for the data block on the second server and generate a synchronizing flag for the data block on the first server.