ZEUS ZARAH vs. Grid
In 1992 ZEUS also started ZARAH (high CPU, high bandwidth)
- "Zentrale Analyse Rechen Anlage für HERA Physics”
- SMP with storage server, later developed into a farm architecture
A centralized installation at DESY
- Seamless integration w/ workstation cluster (or PCs) for interactive use
- Universities bring their own workstation/PC to DESY
- Crucial component: job entry system that defined job execution environment on the central server, accessible from client machines around the world (including workstations/PCs at outside institutes)
- jobsub, jobls, jobget, ...
- Over time it was expanded to the “local area” — PC clusters
Did not address aspects of dissemination to collaborating institutes
- Distribution of calibration and other data bases, software, know-how!
In a world of high-speed networks the Grid advantages become feasible
- seamless access to experiment data to outside—or even on-site—PCs
- Integration with non-ZARAH clusters around the ZEUS institutions
- Database access for physics analysis from scientists around the world