The big experiments in high-energy physics are fertile ground for new developments in computers and communications – witness the World Wide Web, which was developed at CERN. Computer specialist Ben Segal recalls how distributed UNIX boxes took over from CERN’s all-powerful IBM and Cray mainframe workhorses.
I don’t remember exactly who first proposed running physics batch jobs on a UNIX workstation, rather than on the big IBM or Cray mainframes that were doing that kind of production work in 1989 at CERN. The workstation in question was to be an Apollo DN10000, the hottest thing in town with reduced instruction set (RISC) CPUs of a formidable five CERN Units (a CERN Unit was defined as one IBM 370/168, equivalent to four VAX 11-780s) each and costing around SwFr 150 000 for a 4-CPU box.
It must have been the combined idea of Les Robertson, Eric McIntosh, Frederic Hemmer, Jean-Philippe Baud, myself and perhaps some others who were working at that time around the biggest UNIX machine that had ever crossed the threshold of the Computer Centre – a Cray XMP-48, running UNICOS.
At any rate, when we spoke to the Apollo salespeople about our idea, they liked it so much that they lent us the biggest box they had, a DN10040 with four CPUs plus a staggering 64 Mb of memory and 4 Gb of disk space. Then, to round it off, they offered to hire a person of our choice for three years to work on the project at CERN.
In January 1990 the machine was installed and our new “hireling”, Erik Jagel, an Apollo expert after his time managing the Apollo farm for the L3 experiment, coined the name “HOPE” for the new project. (Hewlett-Packard had bought Apollo and OPAL had expressed interest, so it was to be the “HP OPAL Physics Environment”).
We asked where we could find the space to install HOPE in the Computer Centre. We just needed a table with the DN10040 underneath and an Ethernet connection to the Cray, to give us access to the tape data. The reply was: “Oh, there’s room in the middle” – where the recently obsolete round tape units had been – so that was where HOPE went, looking quite lost in the huge computer room, with the IBM complex on one side and the Cray supercomputer on the other.
Soon the HOPE cycles were starting to flow. The machine was surprisingly reliable, and porting the big physics FORTRAN programs was easier than we had expected. After around six months, the system was generating 25 per cent of all CPU cycles in the centre. Management began to notice the results when we included HOPE’s accounting files in the weekly report we made that plotted such things in easy-to-read histograms.
We were encouraged by this success and went to work on a proposal to extend HOPE. The idea was to build a scalable version from interchangeable components: CPU servers, disk servers and tape servers, all connected by a fast netw
