Abstract: A cloud data storage system is provided for multiple clients to access data of files comprising at least one node connecting to a first storage means; at least one namenode module for processing file operations issued from the clients, namenode module issuing data access instructions to access and maintain the metadata on the first storage means; at least one datanode module respectively executing on at least one node, each datanode module functioning to scan and access a second storage means connected thereto; at least one data import module selectively executing on nodes in which datanode module are executing, the data import module scanning a second storage means newly connected to the cloud data storage system and obtaining a corresponding metadata, and executing data migration operation for the data in second storage means without actual physical uploading operation.

Abstract: A cloud data storage system is provided for multiple clients to access data of files comprising at least one node connecting to a first storage means; at least one namenode module for processing file operations issued from the clients, namenode module issuing data access instructions to access and maintain the metadata on the first storage means; at least one datanode module respectively executing on at least one node, each datanode module functioning to scan and access a second storage means connected thereto; at least one data import module selectively executing on nodes in which datanode module are executing, the data import module scanning a second storage means newly connected to the cloud data storage system and obtaining a corresponding metadata, and executing data migration operation for the data in second storage means without actual physical uploading operation.

Abstract: A service workflow generation apparatus, having a quality of service (QoS) monitor for obtaining a plurality of real time QoS values respectively corresponding to a plurality of service elements on the web. A QoS calculation module generates a plurality of possible service workflows composed of the service elements and a plurality of overall QoS values of the possible service workflows based on the real time QoS values by using a Modified Heuristic Algorithm. A service workflow selection module dynamically selects a service workflow from the possible service workflows according to the overall QoS value.