| 摘要 |
A cluster of nodes implements a single distributed file system, comprises at least first and second data centers and a coordination engine process. The first data center may comprise first DataNodes configured to store data blocks of client files, and first NameNodes configured to update a state of a namespace of the cluster. The second data center, geographically remote from and coupled to the first data center by a wide area network, may comprise second DataNodes configured to store data blocks of client files, and second NameNodes configured to update the state of the namespace. The first and second NameNodes are configured to update the state of the namespace responsive to data blocks being written to the DataNodes. The coordination engine process spans the first and second NameNodes and coordinates updates to the namespace stored such that the state thereof is maintained consistent across the first and second data centers. |
