CERN 82-12 23 November 1982 ORGANISATION EUROPÉENNE POUR LA RECHERCHE NUCLÉAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH WORKSHOP ON SOFTWARE IN HIGH-ENERGY PHYSICS (WHERE DO WE GO FROM HERE?) CERN, Geneva, Switzerland 4-6 October 1982 PROCEEDINGS GENEVA 1982 (f) Copyright CERN, Genève, 1982 Propriété littéraire et scientifique réservée pour Literary and scientific copyrights reserved in tous les pays du monde. Ce document ne peut all countries of the world. This report, or être reproduit ou traduit en tout ou en partie any part of it, may not be reprinted or trans• sans l'autorisation écrite du Directeur général lated without written permission of the du CERN, titulaire du droit d'auteur. Dans copyright holder, the Director-General of les cas appropriés, et s'il s'agit d'utiliser le CERN. However, permission will be freely document à des fins non commerciales, cette granted for appropriate non-commercial use. autorisation sera volontiers accordée. If any patentable invention or registrable Le CERN ne revendique pas la propriété des design is described in the report, CERN makes inventions brevetables et dessins ou modèles no claim to property rights in it but offers it susceptibles de dépôt qui pourraient être décrits for the free use of research institutions, manu• dans le présent document; ceux-ci peuvent être facturers and others. CERN, however, may librement utilisés par les instituts de recherche, oppose any attempt by a user to claim any les industriels et autres intéressés. Cependant, proprietary or patent rights in such inventions le CERN se réserve le droit de s'opposer à or designs as may be described in the present toute revendication qu'un usager pourrait faire document. de la propriété scientifique ou industrielle de toute invention et tout dessin ou modèle dé• crits dans le présent document. - iii - ABSTRACT A Workshop on 'Software in High-Energy Physics', attended by some 130 people, took place between 4-6 October 1982 at CERN, Geneva, under the joint sponsorship of CERN (European Organization for Nuclear Research) and ECFA (European Committee for Future Accelerators). Sixteen invited speakers from computer science, from software- and hardware-producing industry, and from other various fields of science, presented their views on the question chosen as the Workshop's subtitle: 'Where do we go from here?'. These proceedings contain most of the invited papers and the dis• cussion contributions, as well as the transcript of a closing panel dis• cussion. - v - INTRODUCTION This Workshop is an attempt to solve a problem of communication arising from history. High-energy physicists were amongst the very early users of large computer systems. Together with the first representatives of what later became computer science, they dis• covered in the i960's the shortcomings of the then available systems and techniques. They developed or proposed solutions which the market did not offer, and created for themselves a computer environment in which the analysis programs they needed could be developed, tested, and exchanged as required. This environment is found, in a similar form, in all computer centres used for high-energy physics; it is dominated by large amounts of data and non-trivial evolutive analysis programs, all shipped around between different computer centres, and the solution adopted is that of FORTRAN programs and extensions by subroutine packages and libraries. The need for frequent adaptation to changing requirements, the necessity for true portability, and the fact that the task of writing and maintaining these programs is car• ried out mostly by physicists who are without either training or specific interest in com• puter science, make this environment remarkably resistant to changes. Today, of course, computer science has established itself, a market of commercially available software products is building up, the classical interface between user and com• puter is being dramatically reviewed, and high-energy physicists have become a comparatively small group of customers amongst many others. All this has made it seem a necessary exercise to assess whether or not the existing approach to software is about to fall behind the state of the art, and to look for areas in which experience, help, or guidance could be brought to high-energy physics from other fields. Some questions for which we hoped to find the answers are the following: - How much of our software can be properly engineered rather than put together in an artistic approach? and by which methods? Can software quality be measured? - Which methods allow us to optimize the necessary breaking of large problems into modular parts? - How closely is the writing of software linked to the computing environment? Is it beneficial to follow the permanent change with the ensuing agonizingly frequent re• appraisal? How easy is it to narrow down the multitude of choices to a reasonable number of solutions? - Do there exist computer users with similar problems, whose solutions could serve as a model for high-energy physics? Does the commercial market offer some solutions? -vi- In consequence, a number of prominent and experienced speakers were invited to present to physicists, most of them from European high-energy physics laboratories, their personal views on these questions: views of computer scientists, views of other computer-intensive branches of science, presentations of future hardware with impact on software writing. Here is the place to thank all invited speakers for their contributions, and for the remarkable understanding they showed towards the problems with which they were confronted. Thanks are also due to all participants who contributed to the lively discussions. R.K. Bock, for the Organizing Committee P. Zanella, for the CERN Management * * * THE PROGRAMME AND ORGANIZING COMMITTEE J. Allaby, CERN V. Blobel, DESI R. Bock, CERN R. Dobinson, CERN R. Fruhwirth, Vienna I. Hughes, Glasgow Ch. Jones, CERN E. Lillestol, Bergen L. Pape, CERN Ch. Petit-Jean-Genaz - Redman, CERN I. Willers, CERN - vu - CONTENTS INTRODUCTION PROGRAMMING M.A. Jackson PHYSICS vs. COMPUTER SCIENCE R. Pike FORTRAN IS ALIVE AND WELL.1 M. Me tealf ADA AND ITS IMPACT ON THE SCIENTIFIC USER R. Marty SOME SOFTWARE TOOLS FOR SCIENTIFIC PROGRAMMING P.P. Worden DATABASE APPLICATIONS IN HIGH ENERGY PHYSICS K.G. Jeffery STORAGE SYSTEMS AND TECHNOLOGY: STATUS AND FUTURE DIRECTIONS M.D. Canon SCIENTIFIC COMPUTING IN METEOROLOGY D.M. Burridge SOFTWARE IN THE OIL INDUSTRY M.C. Turnill SOFTWARE PROBLEMS IN MAGNETIC FUSION RESEARCH í?. Gruber DATA PROCESSING AT THE EUROPEAN SPACE AGENCY C. Mazza HIGHLIGHTS OF A NEW SYSTEM FOR DATA ANALYSIS P. Svensson THE GRAPHICS FUTURE IN SCIENTIFIC APPLICATIONS - Trends and developments in computer graphics - G. Enderle - vin - OLYMP - EVALUATION OF MULTI-DIMENSIONAL DATA ON VAX 11/780 R. Egloff COMPUTER AIDED DESIGN AROUND THE A300 AIRBUS J. J. Audy PERSONAL WORKSTATIONS I.M. Willers HMINET 2 - A LOCAL X.25 NETWORK CONNECTED TO THE GERMAN PUBLIC DATA NETWORK B. Butscher LOCAL AREA NETWORKS P. Zafiropoulo THE PROVISION OF WIDE-AREA NETWORKING FACILITIES B.J. Charles THE DESY COMPUTER CENTRE: OBJECTIVES TODAY AND TOMORROW P.E. Kuhlmann PANEL DISCUSSION Ch. Jones and I. Villers LIST OF PARTICIPANTS PROGRAMMING M A Jackson Michael Jackson Systems Limited 101 Hamilton Terrace London N W 8 England ABSTRACT The programmer's task is often taken to be the const• ruction of algorithms, expressed in hierarchical structures of procedures : this view underlies the majority of traditional programming languages, such as Fortran. A different view is appropriate to a wide class of problem, perhaps including some problems in High Energy Physics. The programmer's task is regarded as having three main stages: first, an explicit model is constructed of the reality with which the program is concerned; second, this model is elaborated to produce the required program outputs; third, the resulting pro• gram is transformed to run efficiently in the execution environment. The first two stages deal in network structures of sequential processes; only the third is concerned with procedure hierarchies. 1. INTRODUCTION Conventionally, the written version of a conference paper should omit those introductory remarks of a personal nature - such as compliments and thanks to the Program and Organising Committee - that are appropriate to the oral presentation. But not in this case. In addition to thanking the Committee for inviting me to this Workshop, I must firmly disclaim any know• ledge of High Energy Physics and of the programming of problems in that discipline. My unease at this ignorance is somewhat mitigated at finding myself placed so early in the programme of the workshop: clearly, the Comm• ittee are anxious to ensure that my paper should be presented in this state of virgin ignorance, before I can have the advantage of hearing other papers and discussions that might impart some fragments of knowledge. It is my hope, and presumably theirs also, that ideas derived from other programming contexts may prove to have some relevance to the problems in High Energy Physics which are the subject of our meeting. With that hope, I will proceed. 2. THE DIFFICULTY OF PROGRAMMING Programming is not an easy task. This became clear quite early in the history of computing, and has become even clearer as programs become more ambitious in their specifications and in the applications that they serve. Embedded systems and process control systems must be very reliable; computer operating systems are inevitably very complex, and must be efficient; comp• ilers for modern programming languages such as Ada are also complex, and must also be efficient; data processing systems are extremely complex - although their complexity sometimes passes unnoticed because they tend to be loosely - 2 - textured - and must be capable of constant change as the needs of their users change. All this is well known. The problem of programming is exacerbated by the'material of which prog• rams are built.