Developing Monitoring and Debugging Tools for the AP1000 Array Multiprocessor

The LERP project aims to assist the ap1000 programmer with essential monitoring and debugging tools. LERP is based on off-line analysis and replay of an event trace. A common event trace format includes both low level system events and user-defined events. In this paper we address the issues of instrumentation of ap1000 programs with minimal interference, and presentation of traced program behaviour to the user. We describe an interface to the existing display tools ParaGraph and Upshot, and a new compound event analysis tool suited to machines of the ap1000 scale. 1 Introduction The ap1000 is a pioneering member of a class of MIMD wormhole message-passing machines with many hundreds of processors (each of which is a general purpose microprocessor with significant speed and memory in its own right), connected by three communications networks. We may term this class the "kilo-processor" machines. 1 It provides significant challenges to programmers who need to develop correct and effi..

A PADRE in MUFTI (A Multi User Free Text retrieval Intermediary)

The Parallel Document Retrieval Engine (PADRE) has hitherto lacked the ability to support multiple time-sharing searchers, a deficiency which detracted from its cost effectiveness. Extensions, adjuncts and performance improvements are now proposed to permit multiple use and to ensure reasonable response times. This paper describes the proposed multi-user architecture, reports query-processing speed-ups, outlines a number of alternative types of user-interaction client including an interface to network browsers in common use. Implementation progress is reported and potential load handling capacity is discussed. KEYWORDS Text retrieval, information retrieval, parallel computing. 1 Introduction The Parallel Document Retrieval Engine (PADRE) has previously demonstrated that full text scanning methods supported by parallel hardware permit powerful query constructors and rapid response to changing document collections [3, 5, 6]. The addition of paralleldisk -resident inverted file indexes ..