Tandem Computers
Tandem Computers was an American computer manufacturer, who developed his first series NonStop especially fault-tolerant server systems. The company was founded in 1974 and acquired by Compaq in 1997. The fault-tolerant NonStop computers were still developed and sold after the acquisition by Compaq Hewlett -Packard (HP) in 2002, now known as the HP Integrity NonStop server.
History
The Company Tandem Computers was founded in 1974 by a group of Hewlett-Packard engineers to James Treybig. The first system (tandem NonStop I) was brought to market in 1976.
Other important model series of the early years were NonStop II ( 1980), NonStop TXP (1983 ), NonStop VLX (1986) and NonStop Cyclone (1989 ), all of which were constructed in discrete technology. One of the machines from the early 1980s, is on display at the Deutsches Museum Munich as a running system. In the 1990s, the K- series microprocessors MIPS NonStop systems were fitted. 1997 at the new S- series the Dynabus architecture used until then was replaced by the new system architecture " ServerNet ". Instead of a double- designed system bus came a redundant system area network with extremely fast internal routers are used, so that the internal bandwidth of the system could be increased virtually unlimited. The technical concepts of ServerNet later incorporated into the high-speed serial transmission technology InfiniBand.
In the same year, the proprietary operating system Guardian used until then was replaced by a completely new operating system called NonStop OS. NonStop OS is a Unix - character (OSS ), the user interfaces are POSIX -compliant. For compatibility reasons NonStop OS has additionally a Guardian mode (investment protection for existing applications).
Tandem Computers was acquired by Compaq for nearly three billion dollars in 1997. The systems were then on sold under the name " Compaq Himalaya".
The Compaq was again taken over by Hewlett -Packard in 2002. For this company, founded by former HP employees has landed after 28 years at HP. For HP, the product name was changed to HP NonStop. The establishment in 2005 switching to Itanium processors by Intel, the current name of HP Integrity NonStop has been introduced. These systems are now one of the three strategic lines of HP servers.
The NonStop systems are characterized by a high level of reliability and are due to their massively parallel computer architecture extremely highly scalable.
NonStop systems do not contain a "single point of failure" ( single point of failure ), all components such as CPUs, controllers, hard drives, data paths or power supplies are redundant. When a component fails, the system automatically reconfigures ( self-healing effect ). The fault tolerance is implemented not only in hardware but also in the system software. Active Processes and their backup processes are process-pairs, the operating system ensures that even with the occurrence of software errors, the processing continues without interruption and no data is lost. For the application of these processes are transparent, the required failure recovery are handled only at the system level.
This special procedure eliminates the usual high availability clustering, making the system management is greatly simplified. Operation of the system is thus very cost effective at the same time, the system behavior is extremely robust.
According to their characteristics NonStop systems are used primarily where continuous availability is required. Examples include the control of ATM and POS payment systems ( point of sale ) or the functioning of exchange trading systems, such as at the New York Stock Exchange. Another example is course 90, the central ticket sales system in several European railway companies.
In the above-mentioned fields about 70 % of all transactions are handled by NonStop systems worldwide. Other typical applications are the control of communication networks (eg for mobile phones), the control of industrial plants and automatic storage systems or operation of reservation systems, such as the Deutsche Bahn.