NonStop is a series of
server computers introduced to market in 1976 by
Tandem Computers
Tandem Computers, Inc. was the dominant manufacturer of fault-tolerant computer systems for Automated teller machine, ATM networks, banks, stock exchanges, telephone switching centers, 911 systems, and other similar commercial transaction proc ...
Inc., beginning with the NonStop
product line
In marketing jargon, product lining refers to the offering of several related product (business), products for individual sale. Unlike product bundling, where several products are combined into one group, which is then offered for sale as a uni ...
. It was followed by the Tandem Integrity NonStop line of
lock-step fault-tolerant computers, now defunct (not to be confused with the later and much different
Hewlett-Packard
The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company. It was founded by Bill Hewlett and David Packard in 1939 in a one-car garage in Palo Alto, California ...
Integrity
Integrity is the quality of being honest and having a consistent and uncompromising adherence to strong moral and ethical principles and values.
In ethics, integrity is regarded as the honesty and Honesty, truthfulness or of one's actions. Integr ...
product line extension). The original NonStop product line is currently offered by
Hewlett Packard Enterprise
The Hewlett Packard Enterprise Company (HPE) is an American multinational information technology company based in Spring, Texas. It is a business-focused organization which works in servers, storage, networking, containerization software and ...
since Hewlett-Packard Company's split in 2015. Because NonStop systems are based on an integrated hardware/software stack, Tandem and later HPE also developed the NonStop OS
operating system
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ...
for them.
NonStop systems are, to an extent, self-healing. To circumvent
single points of failure, they are equipped with almost all
redundant components. When a mainline component fails, the system automatically falls back to the backup.
These systems can be used by
bank
A bank is a financial institution that accepts Deposit account, deposits from the public and creates a demand deposit while simultaneously making loans. Lending activities can be directly performed by the bank or indirectly through capital m ...
s,
stock exchange
A stock exchange, securities exchange, or bourse is an exchange where stockbrokers and traders can buy and sell securities, such as shares of stock, bonds and other financial instruments. Stock exchanges may also provide facilities for ...
s, payment applications, retail companies, energy and utility services, healthcare organizations, manufacturers, telecommunication providers, transportation, and other enterprises requiring extremely high
uptime
Uptime is a Measurement, measure of system reliability, expressed as the period of system time, time a machine, typically a computer, has been continuously working and available. Uptime is the opposite of downtime.
It is often used as a measure ...
.
History
Originally introduced in 1976 by Tandem Computers Inc., the line was later owned by
Compaq
Compaq Computer Corporation was an American information technology, information technology company founded in 1982 that developed, sold, and supported computers and related products and services. Compaq produced some of the first IBM PC compati ...
(from 1997), Hewlett-Packard Company (from 2003) and Hewlett Packard Enterprise (since 2015). In 2005, the HP Integrity "NonStop i" (or TNS/E) servers, based on
Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...
Itanium
Itanium (; ) is a discontinued family of 64-bit computing, 64-bit Intel microprocessors that implement the Intel Itanium architecture (formerly called IA-64). The Itanium architecture originated at Hewlett-Packard (HP), and was later jointly dev ...
microprocessors, was introduced. In 2014, the first "NonStop X" (or TNS/X) systems, based on Intel
x86-64
x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit extension of the x86 instruction set architecture, instruction set. It was announced in 1999 and first available in the AMD Opteron family in 2003. It introduces two new ope ...
processors, were introduced. Sales of the Itanium-based systems ended in July 2020.
Early NonStop applications had to be specifically coded for
fault tolerance
Fault tolerance is the ability of a system to maintain proper operation despite failures or faults in one or more of its components. This capability is essential for high-availability, mission-critical, or even life-critical systems.
Fault t ...
. That requirement was removed in 1983 with the introduction of the Transaction Monitoring Facility (TMF), along with Pathway transaction management software and SCOBOL applications (or, later, NonStop Tuxedo transaction management software), which handles the various aspects of fault tolerance on the system level.
Software
NonStop OS is a
message-based operating system designed for fault tolerance. It works with process pairs and ensures that backup processes on redundant CPUs take over in case of a process or CPU failure. Data integrity is maintained during those takeovers; no transactions or data are lost or corrupted.
The operating system as a whole is branded NonStop OS and includes the Guardian layer, which is a low-level component of the operating system and the Open System Services (OSS) personality which runs atop this layer, which implements a Unix-like interface for other components of the OS to use.
The operating system and application are both designed to support the fault tolerant hardware. The operating system continually monitors the status of all components, switching control as necessary to maintain operations. There are also features designed into the software that allow programs to be written as continuously available programs. That is accomplished using a pair of processes where one process performs all the primary processing and the other serves as a "hot backup", receiving updates to data whenever the primary reaches a critical point in processing. Should the primary stop, the backup steps in to resume execution using the current transaction.
The systems support
relational database management system
A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970.
A Relational Database Management System (RDBMS) is a type of database management system that stores data in a structured for ...
s like
NonStop SQL
NonStop SQL is a commercial relational database management system that is designed for fault tolerance and scalability, currently offered by Hewlett Packard Enterprise. The latest version is SQL/MX 3.4.
The product was originally developed by Tan ...
and hierarchical databases such as
Enscribe
Enscribe is the native hierarchical database in the commercial HP NonStop (Tandem) servers. It is designed for fault tolerance and scalability and is currently offered by Hewlett Packard Enterprise.
The product was originally developed by Ta ...
.
Languages supported include
Java
Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...
,
C,
C++,
COBOL
COBOL (; an acronym for "common business-oriented language") is a compiled English-like computer programming language designed for business use. It is an imperative, procedural, and, since 2002, object-oriented language. COBOL is primarily ...
, SCOBOL (Screen COBOL),
Transaction Application Language
Transaction Application Language or TAL (originally "Tandem Application Language") is a block-structured, procedural language optimized for use on Tandem (and later HP NonStop) hardware. TAL resembles a cross between C and Pascal. It was the ori ...
(TAL), etc. It uses the scripting and job control language
TACL (Tandem Advanced Command Language), and is written in TAL and C.
Hardware

The HPE Integrity NonStop computers are a line of
fault-tolerant, message-based server computers based on the
Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...
Xeon
Xeon (; ) is a brand of x86 microprocessors designed, manufactured, and marketed by Intel, targeted at the non-consumer workstation, server, and embedded markets. It was introduced in June 1998. Xeon processors are based on the same archite ...
processor platform,
and optimized for transaction processing. Average availability levels of 99.999% have been observed. NonStop systems feature a
massively parallel processing (MPP) architecture and provide linear scalability. Each CPU runs its own copy of the OS, and systems can be expanded up to over 4000 CPUs. This is a
shared-nothing architecture
A shared-nothing architecture (SN) is a distributed computing architecture in which each update request is satisfied by a single node (processor/memory/storage unit) in a computer cluster. The intent is to eliminate contention among nodes. Nodes do ...
— a "share nothing" arrangement also known as
loosely coupled multiprocessing.
Due to the integrated hardware/software stack and a
single system image
In distributed computing, a single system image (SSI) cluster is a cluster (computing), cluster of machines that appears to be one single system. The concept is often considered synonymous with that of a distributed operating system, but a single i ...
for even the largest configurations, system management requirements for NonStop systems are rather low. In most deployments there is just a single production server, not a complex
server farm
A server farm or server cluster is a collection of Server (computing), computer servers, usually maintained by an organization to supply server functionality far beyond the capability of a single machine. They often consist of thousands of compu ...
.
Most customers also have a backup server in a remote location for
IT disaster recovery
IT disaster recovery (also, simply disaster recovery (DR)) is the process of maintaining or reestablishing vital infrastructure and systems following a natural or human-induced disaster, such as a storm or battle. DR employs policies, tools, an ...
. There are standard products to keep the data of the production and the backup server in sync, for example, HPE's Remote Database Facility (RDF), hence there is fast takeover and little to no data loss also in a disaster situation with the production server being disabled or destroyed.
HP also developed a
data warehouse
In computing, a data warehouse (DW or DWH), also known as an enterprise data warehouse (EDW), is a system used for Business intelligence, reporting and data analysis and is a core component of business intelligence. Data warehouses are central Re ...
and
business intelligence
Business intelligence (BI) consists of strategies, methodologies, and technologies used by enterprises for data analysis and management of business information. Common functions of BI technologies include Financial reporting, reporting, online an ...
server line,
HP Neoview, based on the NonStop line. It acted as a
database server
A database server is a server which uses a database application that provides database services to other computer programs or to computers, as defined by the client–server model. Database management systems (DBMSs) frequently provide database- ...
, providing NonStop OS and
NonStop SQL
NonStop SQL is a commercial relational database management system that is designed for fault tolerance and scalability, currently offered by Hewlett Packard Enterprise. The latest version is SQL/MX 3.4.
The product was originally developed by Tan ...
, but lacked the
transaction processing
In computer science, transaction processing is information processing that is divided into individual, indivisible operations called ''transactions''. Each transaction must succeed or fail as a complete unit; it can never be only partially c ...
functionality of the original NonStop systems. The line was
retired, and no longer
marketed, as of 24 January 2011.
See also
*
List of compilers
This page is intended to list all current compilers, compiler generators, Interpreter (computing), interpreters, translators, tool foundations, Assembler (computing), assemblers, automatable command line interfaces (Shell (computing), shells), et ...
- includes some compilers for NonStop
*
Master-checker
Master-checker or master/checker is a hardware-supported fault tolerance architecture for multiprocessor
Multiprocessing (MP) is the use of two or more central processing units (CPUs) within a single computer system. The term also refers to th ...
*
Reliability engineering
Reliability engineering is a sub-discipline of systems engineering that emphasizes the ability of equipment to function without failure. Reliability is defined as the probability that a product, system, or service will perform its intended functi ...
*
Stratus Technologies
Stratus Technologies, Inc. is a major producer of fault tolerant computer servers and software. The company was founded in 1980 as Stratus Computer, Inc. in Natick, Massachusetts, and adopted its present name in 1999. The current CEO and presi ...
References
Sources
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External links
HPE NonStop
{{DEFAULTSORT:NonStop
Hewlett Packard Enterprise
Computer-related introductions in 1976
Computer architecture
Fault-tolerant computer systems
HPE servers
HP software
MIPS architecture
Proprietary operating systems
X86-64 operating systems