With the emergence of high performance local networks, distributed memory parallel programming has entered a new era. Indeed, parallel programming is no more reserved for highly specialized technicians : (almost...) everyone can now afford a small pile of PCs, i.e. a collection of PCs interconnected by a high-speed network. Unfortunately, parallel programming remains "esoteric" for most of end-users accustomed to classical mono-processor programming. Designing and optimizing an inter-process communication scheme, balancing workloads between processors, optimizing computing and network resources is not trivial and, in the lack of a high level programming environment, programming a complex parallel application resembles like piloting a Formula 1 car : one needs advanced skills to use it at its maximum power (... and not to have bad surprises).
In this talk, we will present two parallel programming environments that have been developed in your lab. PM2 proposes users to design their application as a collection of threads that will be spread over the network and migrated for load balancing purpose. On another side, the Distributed Shared Memory (DSM) system DOSMOS implements, above a distributed memory architecture, a programming model allowing a transparent manipulation of shared data. Thus, in practice, DOSMOS handles all the inter-process communications and maintains the coherence of the shared data. In order to ensure scalability and efficiency, several novel features have been introduced as the grouping of processes, the possibility of mixing message-passing (PVM) code and DSM code, the definition of optimized weak consistency protocols, the integration of monitoring facilities. Initially developed on top of PVM, DOSMOS is now available on top of MPI... and PM2.
Finally, we will discuss experiments and point out current developments that try to take advantage of both multithreading and DSM programming.
Keywords: parallel programming environments, distributed shared memory, threads.
Der Vortragende:
Lionel Brunie received his PhD in 1992 from University Joseph Fourier,
Grenoble, France. His researches were then concerned with medical
informatics, more specifically with the fusion of multimodal medical
images and its application to the 3D dynamic imaging of the scoliosis.
Since 1993, Lionel Brunie has been assistant professor and then in 1997
associate professor at Ecole Normale Superieure of Lyon.
His domains of interest include parallel databases, distributed operating systems, medical images management systems (PACS - RIS), performance evaluation of parallel applications. His lectures are delivered on databases, parallel databases, distributed systems, parallel computing. Lionel Brunie is (co-)author of more than 50 research papers published in international conferences proceedings or international journals and 3 international patents.
He was the leader of the LIP research group "Parallel databases, Automatic parallelization, Parallel programming tools and environments" including 22 researchers (permanent researchers and PhD students). He is currently the deputy leader of the INRIA team-project REMAP. He is also the leader of several international research projects concerned. This october he became professor at the INSA Lyon.
Referent: Prof. Dr. Lionel Brunie,
Ecole normale supérieure de Lyon
Laboratoire de l'Informatique du Parallélisme
URA 1398 du CNRS
École normale supérieure de Lyon - 46, allée
allée d'Italie - 69364 LYON cedex 07 - France
Zeitpunkt: Mittwoch, 18. November 1998, 17 Uhr c. t.
Ort: HS 1 der Universität Klagenfurt