Abstract: According to one embodiment of load balancing, a system comprises a plurality of nodes being configured to allow input/output (I/O) access to a plurality of data, each data being accessed as a value via a unique key which is associated with the value as a key-value pair, the data being distributed and stored among the plurality of nodes based on hush values of the keys. Each node includes an I/O module to record a number of I/O accesses to each key of a plurality of keys associated with the plurality of data as values, respectively, to form key-value pairs. If resource utilization of a node exceeds a preset threshold, then the node is an overloaded node, and the overloaded node migrates out a part of the key-value pairs in the overloaded node in order to reduce the resource utilization to a level below the preset threshold.

Abstract: A distributed storage system has MDSs (metadata servers). Directories of file system namespace are distributed to the MDSs based on hash value of inode number of each directory. Each directory is managed by a master MDS. When a directory grows with a file creation rate greater than a preset split threshold, the master MDS constructs a consistent hashing overlay with one or more slave MDSs and splits directory entries of the directory to the consistent hashing overlay based on hash values of file names under the directory. The number of MDSs in the consistent hashing overlay is calculated based on the file creation rate. When the directory continues growing with a file creation rate that is greater than the preset split threshold, the master MDS adds a slave MDS into the consistent hashing overlay and splits directory entries to the consistent hashing overlay based on hash values of file names.

Abstract: A global namespace (GNS) is constructed across heterogeneous network-attached storage (NAS) devices by organizing metadata servers into a cluster layer having cluster nodes and a consistent hashing overlay layer having overlay nodes. The global namespace is distributed based on workload at the cluster and overlay nodes, and a portion of the GNS namespace may be migrated from one layer to the other. Cluster nodes may be added to the cluster layer, overlay nodes may be added to the consistent hashing overlay layer. Further, a cluster node may become an overlay node or an overlay node may become a cluster node. To access the global namespace, a request for namespace metadata managed by a cluster node is serviced by the cluster node, but if the requested namespace metadata have been migrated to the consistent hashing overlay layer, the cluster node will forward the request to the responsible overlay node for servicing.

Abstract: A geographically distributed storage system including a global Peer-To-Peer (P2P) ring and a local P2P ring. The global P2P ring includes all storage nodes and the local P2P ring includes a group of the storage nodes. Each of the group of storage node belongs to the global P2P ring and the local P2P ring and each storage node includes global and local management information. The global management information includes a node table for managing topology information of a network connecting the group, a metadata table for managing locations of stored data objects, and a global routing table for managing routing in the global P2P ring. The local management information includes an object management table for managing stored data objects in the group, a Logical Unit (LU) management table for managing logical units in the group and a local routing table used for managing routing in the local P2P ring.

Abstract: A distributed storage system employs a Key-Value Store to dynamically change a table layout scheme based on user access patterns. The system can be used as a basic architecture to construct a distributed Key-Value Store to support both row-oriented and column-oriented table layout schemes, by using DHT (Distributed Hash Table) technology for high scalability.

Abstract: A global namespace (GNS) is constructed across heterogeneous network-attached storage (NAS) devices by organizing metadata servers into a cluster layer having cluster nodes and a consistent hashing overlay layer having overlay nodes. The global namespace is distributed based on workload at the cluster and overlay nodes, and a portion of the GNS namespace may be migrated from one layer to the other. Cluster nodes may be added to the cluster layer, overlay nodes may be added to the consistent hashing overlay layer. Further, a cluster node may become an overlay node or an overlay node may become a cluster node. To access the global namespace, a request for namespace metadata managed by a cluster node is serviced by the cluster node, but if the requested namespace metadata have been migrated to the consistent hashing overlay layer, the cluster node will forward the request to the responsible overlay node for servicing.

Abstract: A geographically distributed storage system including a global Peer-To-Peer (P2P) ring and a local P2P ring. The global P2P ring includes all storage nodes and the local P2P ring includes a group of the storage nodes. Each of the group of storage node belongs to the global P2P ring and the local P2P ring and each storage node includes global and local management information. The global management information includes a node table for managing topology information of a network connecting the group, a metadata table for managing locations of stored data objects, and a global routing table for managing routing in the global P2P ring. The local management information includes an object management table for managing stored data objects in the group, a Logical Unit (LU) management table for managing logical units in the group and a local routing table used for managing routing in the local P2P ring.