NonStop/spl reg/ advanced architecture

For nearly 30 years the Hewlett Packard NonStop Enterprise Division (formerly Tandem Computers Inc.) has produced highly available, fault-tolerant, massively parallel NonStop computer systems. These vertically integrated systems use a proprietary operating system and specialized hardware for detecting, isolating, and recovering from faults. The NonStop advanced architecture (NSAA) uses dual or triple modular redundant fault-tolerant servers built from standard HP 4-way SMP Itanium/spl reg/2 server processor modules, memory boards, and power infrastructure. A unique synchronization mechanism allows fully compared operations from loosely synchronized processor modules. In addition, the NSAA improves system availability by additional hardware fault masking, and significantly lowers cost by leveraging existing high-volume Itanium server components.