Multi-node media server with efficient work scheduling

摘要

A multi-node video server system in accordance with the invention comprises disk storage associated with a first node which stores at least a portion of a video presentation in the form of plural data blocks, each data block comprising a viewing time segment of the presentation. RAM buffer in a second node receives and stores data blocks of the video presentation from the disk storage in the first node, upon an initial request by a first viewing terminal to view a portion of the video presentation. A communication module in the second node outputs the data blocks, as an isochronous data stream, to requesting terminals. A host controller is coupled to the video server nodes and receives requests from viewing terminals for the video presentation. The host controller causes the communication module in the second node to connect to a viewing terminal which renders the initial request. Additional viewing terminals requesting the same video presentation are also connected to the same communication module if their requests are received within a time period from the initial request that does not exceed a sum of viewing time segments represented by data blocks stored in the RAM buffer. In this manner, both the first requestor and subsequent requesting viewing terminals are enabled to receive the audiovisual presentation directly from the same buffer without requiring additional disk accesses for the subsequent viewers. Avoidance of additional internal video server communications is thus achieved.