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Encyclopedia > Transaction Processing Facility
z/TPF
Website: IBM: z/TPF operating system
Company/
developer:
IBM
OS family: z/TPF
Source model: not open source, source code to licenced users with restrictions
Latest stable release: V1R1 / December, 2005
Kernel type: Real time
License: Proprietary monthly license charge (MLC)
Working state: Current
For other meanings of TPF, see TPF (disambiguation).

TPF is an IBM real-time operating system for mainframes descended from the IBM System/360 family, including zSeries and System z9. The name is an initialism for Transaction Processing Facility. A website (or Web site) is a collection of web pages, images, videos and other digital assets and hosted on a particular domain or subdomain on the World Wide Web. ... The term software company could be applied to; a) a company that produces software or b) a company that distributes software from a third party or c) a company that provides services for software. ... A software developer is a person who is concerned with one or more facets of the software development process, a somewhat broader scope of computer programming or a specialty of project managing. ... International Business Machines Corporation (known as IBM or Big Blue; NYSE: IBM) is a multinational computer technology and consulting corporation headquartered in Armonk, New York, USA. The company is one of the few information technology companies with a continuous history dating back to the 19th century. ... TPF is also the NASA Terrestrial Planet Finder project. ... 2005 (MMV) was a common year starting on Saturday of the Gregorian calendar. ... A kernel connects the application software to the hardware of a computer. ... A software license is a legal agreement which may take the form of a proprietary or gratuitous license as well as a memorandum of contract between a producer and a user of computer software. ... Proprietary software is software with restrictions on using, copying and modifying as enforced by the proprietor. ... TPF can stand for The Phoenix Federation - A mysterious group who hold the secrets of life, the universe and predictions of the future in The Book of The Phoenix; TPF is shrouded in secrecy and control many high ranking positions around the globe, all in its quest for world domination. ... International Business Machines Corporation (IBM, or colloquially, Big Blue) (NYSE: IBM) (incorporated June 15, 1911, in operation since 1888) is headquartered in Armonk, New York, USA. The company manufactures and sells computer hardware, software, and services. ... An operating system (OS) is a set of computer programs that manage the hardware and software resources of a computer. ... SAS 8 on an IBM mainframe under 3270 emulation An IBM mainframe is a mainframe computer made by IBM. // From 1952 into the late 1960s, IBM manufactured and marketed several large computer models, known as the IBM 700/7000 series. ... System/360 Model 65 operators console, with register value lamps and toggle switches (middle of picture) and emergency pull switch (upper right). ... Since December, 2001, IBM designates all its mainframes with the name eServer zSeries, with the e depicted in IBMs well-known red trademarked symbol. ... Since December, 2001, IBM designates all its mainframes with the name eServer zSeries, with the e depicted in IBMs well-known red trademarked symbol. ... Acronyms and initialisms are abbreviations formed from the initial letter or letters of words, such as NATO and XHTML, and are pronounced in a way that is distinct from the full pronunciation of what the letters stand for. ...


TPF evolved from the Airlines Control Program (ACP), a free package developed in the mid-1960s by IBM in association with major North American and European airlines. In 1979, IBM introduced TPF as a replacement for ACP — and as a priced software product. The new name suggests its greater scope. Airlines Control Program, or ACP, was the operating system developed by IBM in 1969 for processing airline reservations and related data. ... The 1960s decade refers to the years from January 1, 1960 to December 31, 1969, inclusive. ... International Business Machines Corporation (IBM, or colloquially, Big Blue) (NYSE: IBM) (incorporated June 15, 1911, in operation since 1888) is headquartered in Armonk, New York, USA. The company manufactures and sells computer hardware, software, and services. ... For the song by the Smashing Pumpkins, see 1979 (song). ...


Current users include Sabre (reservations), Amadeus (reservations), VISA International (authorizations), Holiday Inn (central reservations), CBOE (order routing), Singapore Airlines, KLM, Qantas, Amtrak, Marriott International and the NYPD (911 system). Sabre is a computer reservations system used by airlines, railways, hotels, and other travel companies. ... The Amadeus Global Travel Distribution System is an electronic reservation system. ... Visa is a brand of credit card and debit card operated by the Visa International Service Association of San Francisco, California, USA, an economic joint venture of 21,000 financial institutions that issue and market Visa products. ... Holiday Inn is a brand name applied to hotels within the InterContinental Hotels Group. ... The Chicago Board Options Exchange (CBOE) is one of the worlds largest options exchanges with an annual trade of over 15 billion shares of stock options in some 1200 companies. ... Singapore Airlines Limited (Abbreviation: SIA; Malay: Syarikat Penerbangan Singapura, Tamil: சிங்கப்பூர் ஏர்லைன்ஸ், Chinese: ; pinyin: ; abbreviated 新航) SGX: S55 is the national airline of Singapore. ... KLM Royal Dutch Airlines (in full: Koninklijke Luchtvaart Maatschappij, literally Royal Aviation Company; usual English: Royal Dutch Airlines) is a subsidiary of Air France-KLM. Prior to its merger with Air France, KLM was the national airline of the Netherlands. ... Qantas (pronounced ) is the name and callsign of the national airline of Australia and the worlds third oldest continuously running independent airline behind KLM and Avianca. ... Acela Express in West Windsor, NJ Amtrak Cascades service with tilting Talgo trainsets in Seattle, Washington Amtrak train in downtown Orlando, Florida For other uses, see Amtrak (disambiguation). ... Marriott International, Inc. ... The New York City Police Department (NYPD) , the largest police department in the United States, has primary responsibility for law enforcement and investigation within the five boroughs of New York City. ...


TPF delivers fast, high-volume, high-throughput transaction processing, handling large, continuous loads of essentially simple transactions across large, geographically dispersed networks. The world's largest TPF-based systems are easily capable of processing tens of thousands of transactions per second. TPF is also designed for highly reliable, continuous (24x7) operation. It is not uncommon for TPF customers to have continuous online availability of a decade or more, even with system and software upgrades.


While there are other industrial-strength transaction processing systems, notably IBM's own CICS and IMS, TPF's raison d'être is extreme volume, large numbers of concurrent users and very fast response times, for example, VISA credit card processing during the holiday shopping season. CICS® (Customer Information Control System) is a transaction server that runs primarily on IBM mainframe systems under z/OS or z/VSE. CICS is available for other operating systems, notably i5/OS, OS/2, and as the closely related IBM TXSeries software on AIX, Windows, and Linux, among others. ... Information Management System (IMS) is a joint hierarchical database and information management system. ... Visa is a brand of credit card and debit card operated by the Visa International Service Association of San Francisco, California, USA, an economic joint venture of 21,000 financial institutions that issue and market Visa products. ...


TPF implements an application known as PARS. Many airlines use this passenger reservation application or its international version IPARS. TPF was traditionally a 370 assembly language environment for performance reasons, and many TPF assembler applications persist. However, more recent versions of TPF encourage the use of C. Another programming language called SabreTalk was born and died on TPF. One of TPF's major components is a high performance, specialized database facility called TPFDF. PARS (Programmable Airline Reservation System) is an IBM proprietary large scale airline reservation application, executing under the control of IBMs ACP (and later its successor, TPF). ... An assembly language is a low-level language used in the writing of computer programs. ... C is a general-purpose, procedural, imperative computer programming language developed in 1972 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system. ... A programming language is an artificial language that can be used to control the behavior of a machine, particularly a computer. ... SabreTalk is a dialect of PL/1 for the S/360 IBM mainframes running the TPF platform. ...


It is common for TPF sites to also use other IBM mainframe operating systems, such as z/OS and z/VM, for offline and complementary processing. It is also possible to run a close cousin of TPF, called ALCS, atop z/OS rather than as a separate operating system. All these operating systems usually coexist on the same physical hardware since IBM mainframes feature multiple ways of partitioning, to handle mixed workloads. z/OS Welcome Screen seen through a terminal emulator The title of this article begins with a capital letter due to technical limitations. ... VM is an early and influential virtual machine operating system from IBM, apparently the first true virtual machine system. ... ALCS is an application server that provides industrial-strength, online transaction management for mission-critical applications. ...


IBM announced the delivery of the next release of TPF, dubbed z/TPF V1.1, in September 2005. Most significantly, z/TPF adds 64-bit addressing and mandates use of the 64-bit GNU development tools. The GCC compiler will be the only supported compiler for z/TPF. 2005 (MMV) was a common year starting on Saturday of the Gregorian calendar. ... GNU (pronounced ) is a computer operating system - consisting of a kernel, libraries, system utilities, compilers, and end-user application software - composed entirely of free software. ... The GNU Compiler Collection (usually shortened to GCC) is a set of programming language compilers produced by the GNU Project. ...

Contents

Operating Environment

Tightly Coupled

TPF is capable of running in a multiprocessor, that is, on mainframe systems in which there is more than one CPU. Within the community, the CPUs are referred to as Instruction Streams or simply I-streams. If TPF is running on a mainframe with 1 I-stream or in an LPAR with only one I-stream dedicated, it is said to be running Uni-processor or simply Uni. However on mainframes or LPARs with more than one I-stream, TPF runs what is known as tightly-coupled. Multiprocessing is traditionally known as the use of multiple concurrent processes in a system as opposed to a single process at any one instant. ... In IBM mainframe computing, a Logical Partition, commonly called an LPAR, is a virtualized computing environment abstracted from all physical devices. ...


Due to the reentrant nature of TPF programs and the control program, this is made possible as no active piece of work modifies any program. The default is to run on the main I-stream which is given as the lowest numbered I-stream found during IPL. However users and/or programs can initiate work on other I-streams via internal mechanisms in the API which let the caller dictate which I-stream to initiate the work on. In the new z/TPF, the system itself will try to load balance by routing any application that does not request a preference or affinity to I-streams with less work than others. A computer program or routine is described as reentrant if it is designed in such a way that a single copy of the programs instructions in memory can be shared by multiple users or separate processes. ...


In the TPF architecture, each I-stream shares common core, except for a 4Kb in size prefix area for each I-stream. In other instances where core data must or should be kept separate, the application designer typically carves up reserved storage areas into a number of sections equal to the number of I-streams. A good example of the TPF system doing this can be found with TPFs support of I-stream unique globals. Proper access to these carved sections of core are made by taking the base address of the area, and adding to it the product of the I-stream relative number times the size of each area.


Loosely Coupled

TPF is capable of supporting multiple mainframes (of any size themselves - be it single I-stream to multiple I-stream) connecting to and operating on a common database. Currently, 32 IBM mainframes may share the TPF database; if such a system were in operation, it would be called 32-way loosely coupled. The simplest loosely coupled system would be two IBM mainframes sharing one DASD (Direct Access Storage Device). In this case the control program would be equally loaded into core and each program or record on DASD could be potentially accessed by either mainframe.


In order to serialize accesses between data records on a loosely coupled system, a practice known as Record locking must be used. This means that when one mainframe processor obtains a hold on a record, the mechanism must prevent all other processors from obtaining the same hold and communicate to the requesting processors that they are waiting. Within any tightly coupled system this is easy to manage between I-streams via the use of the Record Hold Table. However when the lock is obtained offboard of the TPF processor in the DASD control unit, an external process must be used. Historically the record locking was accomplished in the DASD control unit via an RPQ known as LLF (Limited Locking Facility) and later ELLF (extended). Given that most if not all DASD on the market today do not have these RPQs, other methods such as IBMs Coupling Facility must be used to manage record locks. Record locking is the technique of preventing simultaneous access to data in a database, to prevent inconsistent results. ...


Processor Shared Records

Records that absolutely must be managed by a record locking process are those which are processor shared. In TPF most record accesses are done by using record type and ordinal. So if you had defined a record type in the TPF system of 'FRED' and gave it 100 records or ordinals, then in a processor shared scheme record type 'FRED' ordinal '5' would resolve to the exact same file address on DASD - clearly neccessitating the use of a record locking mechanism. Record locking is the technique of preventing simultaneous access to data in a database, to prevent inconsistent results. ...


All processor shared records on a TPF system will be accessed via the exact same file address which will resolve to the exact same location.


Processor Unique Records

A processor unique record is one that is defined such that each processor expected to be in the loosely coupled complex has a record type of 'FRED' and perhaps 100 ordinals. However, if a user on any 2 or more processors examines the file address that record type 'FRED', ordinal '5' resolves to, they will note a different physical address is used.


TPF Attributes

What TPF is not

TPF has no graphical user interface (hereafter GUI). TPF's built-in user interface is line driven with simple text screens that scroll upwards. There are no mice, windows, or icons on a TPF Prime CRAS. All work is accomplished via the use of typed one or two line commands, similar to early versions of UNIX sans X Window. GUI can refer to the following: GUI is short for graphical user interface, a term used to describe a type of interface in computing. ...


TPF also does not include a compiler/assembler, text editor, or the concept of a desktop. TPF application source code is typically kept in PDSs on a z/OS system. However, some previous installations of TPF kept source code in z/VM-based files and used the CMS update facility to handle versioning. Currently the z/OS compiler/assembler is used to build TPF code into object modules, producing load files that the TPF "online system" can accept. Starting with z/TPF 1.1, Linux will be the build platform. VM is an early and influential virtual machine operating system from IBM, apparently the first true virtual machine system. ...


Using TPF requires an intimate knowledge of the Operations Guide since there is no shipped support for any type of online command "directory" that you might find on other platforms. Commands created by IBM and shipped by IBM for the running and administration of TPF are referred to as "Z-messages" as they are all prefixed with the letter "Z." Other letters are reserved so that customers may write their own commands.


TPF has extremely limited capability to debug itself. Typically third party software packages such as IBM's TPF Tool Kit or Step by Step Trace from Bedford Associates are employed to aid in the tracing and tracking of errant TPF code. Since TPF can run as a second level guest under IBM's z/VM, a user can employ the VM trace facility to closely follow the execution of code. TPF will allow certain types of function traces to operate and dump their data to a tape, typically through user exits that present parameters to a called function or perhaps the contents of a block of storage. There are some other types of trace information that TPF can collect in core while running, and this information gets "dumped" whenever the system encounters a severe error. International Business Machines Corporation (known as IBM or Big Blue; NYSE: IBM) is a multinational computer technology and consulting corporation headquartered in Armonk, New York, USA. The company is one of the few information technology companies with a continuous history dating back to the 19th century. ...


What TPF is

TPF is highly optimized to permit messages from the supported network to either be switched out to another location, routed to an application (specific set of programs) or to permit extremely efficient accesses to database records.


Data records

Historically all data on the TPF system had to fit in fixed record (and core block) sizes of 381, 1055 and 4K bytes. This was due in part to the physical record sizes of blocks located on DASD. Much overhead was saved by freeing up any part of the operating system from breaking large data entities into smaller ones during file operations, and reassembling same during read operations. Since IBM hardware does I/O via the use of channels and channel programs, TPF would generate very small and efficient channel programs to do its I/O - all in the name of speed. Since the early days also placed a premium on the size of storage media - be it memory or disk, TPF applications evolved into doing very powerful things while using very little resource.


Today, much of these limitations are removed. In fact, only because of legacy support are smaller than 4K DASD records still used. With the advances made in DASD technology, a read/write of a 4K record is just as efficient as a 1055 byte record. The same advances have increased the capacity of each device so that there is no longer a premium placed on the ability to pack data into the smallest model as possible.


Programs and Residency

TPF also had its programs allocated as 381, 1055 and 4K bytes in size and each program consisted of a single record (aka segment). Therefore a comprehensive application could reside in many segments to make the package. With the advent of C-support, application programs were no longer limited to 4K sizes, much larger C programs could be created, loaded to the TPF system as multiple 4K records and read into memory during a fetch operation and correctly reassembled. Since in the past core memory was at a premium, only highly used programs ran 100% of the time as core resident, most ran as file resident. Given the limitations of older hardware, and even todays relative limitations, a fetch of a program, be it a single 4K record or many, is expensive. Since core memory is monetarily cheap and physically much much larger, greater numbers of programs could be allocated to reside in core. With the advent of z/TPF, all programs will reside in core - eventually - the only question is when they get fetched the first time.


Before z/TPF, all assembler language programs were limited to 4K in size. Assembler is a more efficient language to program in so a lot of function can be packed into relatively few 4K segments of assembler code compared to C in 4K segments. However, C language programming is much easier to obtain skilled people in, so most if not all new development is done in C. Since z/TPF allows assembler programs to be repackaged into 1 logical file, critical legacy applications can be maintained and actually improve efficiency - the cost of entering one of these programs will now come at the initial enter when the entire program is fetched into core and logical flow through the program is accomplished via simple branch instructions, instead of a dozen or so IBM instructions previously needed to perform what is known as 'core resident enter/back'.


Core Usage

Historically and in step with the previous, core blocks - memory - were also 381, 1055 and 4K bytes in size. Since ALL memory blocks had to be of this size, most of the overhead for obtaining memory found in other systems was discarded. The programmer merely needed to decide what size block would fit the need and ask for it. TPF would maintain a list of blocks in use and simply hand the first block on the available list.


Physical memory was carved into sections reserved for each size so a 1055 byte block always came from a section and returned there, the only overhead needed was to add its address to the physical block table's proper list. No compaction or data collection was required.


As applications got more advanced demands for more core increased and once C became available, memory chunks of indeterminate or large size were required. This gave rise to the use of heap storage and of course some memory management routines. To ease the overhead, TPF memory was broken into frames - 4K in size (and now 1Mb in size with z/TPF). If an application needed a certain number of bytes, the number of contiguous frames required to fill that need were granted.


External links

  • TPF Information Center (IBM)
  • z/TPF (IBM)
  • TPF User Group (TPF User Group)
  • TPF Minds (A Wiki-based TPF community for sharing TPF knowledge)
  • Blackbeard (Alternative TPF Homepage)
  • Bedford Associates (Suppliers of step by step trace and TPF Consultancy Services)
  • TPFfers (Single largest online community of TPF programmers)
  • PCS Training (Independent training company specialising in TPF)

  Results from FactBites:
 
Transaction processing - Wikipedia, the free encyclopedia (1061 words)
Transaction processing allows multiple individual operations on a database to be linked together automatically as a single, indivisible transaction.
Transaction processing guards against hardware and software errors that might leave a transaction partially completed, with a database left in an unknown, inconsistent state.
Today a number of transaction processing systems are available that work at the inter-program level and which scale to large systems, including mainframes.
transaction processing: Information from Answers.com (2119 words)
Transaction processing is a tool that can help growing businesses deal with their increasing number of transactions.
Transaction processing on the Internet includes several options for those who want to use a credit card or a checking account to pay for goods that do not originate from a typical e-business site, almost as if it is digital cash.
Transaction processing is designed to maintain a database in a known, consistent state, by ensuring that any operations carried out on the database that are interdependent are either all completed successfully or all cancelled successfully.
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