A multi-service storage architecture

Abstract

This paper gives an overview of a new Multi Service Storage Architecture (MSSA) which has been designed for a broader range of clients than traditional file servers and in particular for emerging clients such as real-time multimedia applications.The proposed architecture is an open hierarchy of services in which both unstructured and structured data are supported. Any client which requires high performance and a minimal service can use the lowest level directly. A principal-specific capability scheme is used for protection.The paper outlines the designs of the two basic components of the architecture, the Low Level and High Level Storage Services (LLSS and HLSS). The LLSS has a traditional storage service interface, at the byte sequence or subsequence level, and exploits non-volatile memory to achieve high performance. The HLSS provides optional support for structured objects through a flexible but efficient storage type generation scheme together with existence control and concurrency control at any required granularity.We have developed tools for performance evaluation which allow us to monitor the LLSS under artificial load generators and benchmarks as well as local applications. As a side effect we can compare the properties of these loads.We outline how the storage services are being used as a basis for a directory service, a database programming language, an integrated virtual memory system and the representation, storage and retrieval of structured multimedia objects with synchronisation between components.