Oracle International Corporation

William Bailey

Mark R Moore

Mark A Porter

Farzad Nazem

Jeffrey C Olkin

Sue K Lee

Andrew Laursen

A method and apparatus for coordinating access to a storage system in a real time processing system is disclosed. In an apparatus including a file server, a storage system, a real time process, and a non-real time process, an apparatus and method is disclosed for coordinating accesses to the storage system, the method includes the steps of: 1) computing an available data rate from a peak bandwidth data transfer rate for the storage system, 2) receiving a first access request from the real time process, the first access request including a request for a requested data rate, 3) granting the first access request if the requested data rate is less than or equal to the available data rate, and 4) allowing the real time process to directly access the storage system at the requested data rate. In addition, the method of the present invention includes the steps of: 1) receiving a second access request from the non-real time process, the second access request including information indicating an identity of a desired file, 2) assigning an assigned data rate to the non-real-time process, the assigned data rate being less than or equal to the available data rate, and 3) allowing the non-real time process to directly access the storage system at the assigned data rate.

System for granting bandwidth for real time processes and assigning

An improved system and method for providing multimedia data in a networked system is disclosed. The present invention provides a platform for distributed client-server computing and access to data over asymmetric real-time networks. A service mechanism allows applications to be split such that client devices (set-top boxes, personal digital assistants, etc.) can focus on presentation, while backend services running in a distributed server complex, provide access to data via messaging across an abstracted interface.

Method and apparatus for scalable, high bandwidth storage retrieval and

A method and apparatus for providing transparent, real time reconstruction of corrupted data from a redundant array of storage units in a manner that imposes no performance degradation for reconstruction of such corrupted data and that does not tie up system resources. The present invention is particularly suited to applications in which data is retrieved from storage equipment in approximately equally sized parcels. Each parcel is divided into 'N' blocks of data. An 'N+1st' parity block for each parcel is derived based on the content of the 'N' blocks of data. The 'N' blocks of data and the parity block for each parcel are stored in stripes of blocks in a redundancy group consisting of 'N+1' data storage units. Data is read from the storage units an entire stripe at a time. To read a stripe, a read request is concurrently sent to each storage unit in the redundancy group, requesting the block of data in that storage unit that corresponds to the stripe being read. Each storage unit independently processes the read request it has received and sends back the requested block as soon as it has been read. As soon as the first 'N' blocks are received, they are XOR'd together to reconstruct the outstanding 'N+1st' block. The 'N' received blocks and the XOR'd sum, representing a reconstruction of the outstanding 'N+1st' block, are delivered to the requesting device or process. The same procedure is used each time data is read. The present invention thus delivers data at a consistent rate regardless of whether a storage unit failure occurs.

Growing community of inventors

Palo Alto, CA, United States of America

William Bailey