Glossary

Asynchronous processing

A means of distributing the processing of an application between systems in an intercommunication environment. The processing in each system is independent of the session on which requests are sent and replies are received. No direct correlation can be made between requests and replies and no assumptions can be made about the timing of replies.

APF (Authorized Program Facility)

A facility that enables identification of programs that are authorized to use restricted functions.

Audit trail

A manual or computerized means for tracing the transactions affecting the contents of a record.

Back-end System

The CICS or IMS transaction processing system provided by IBM.

Batch processing

  • Type of data processing in which a number of input items are grouped for processing serially with a minimum of operator intervention and no end-user interaction.
  • Serial processing of computer programs.
  • Pertaining to the technique of executing a set of computer programs so that each is completed before the next program of the set is started.

BMP (Batch Message Processing Program)

An IMS batch processing program that has access to online databases controlled by DBCTL and message queues. BMPs run online; however, like programs in a batch environment, they are started with job control language (JCL).

CEMT

A CICS transaction that invokes all the master terminal functions. These functions include inquiring and changing the value of parameters used by CICS, altering the status of system resources, terminating tasks, and shutting down CICS.

CICS (Customer Information Control System)

IBM's general-purpose online transaction processing (OLTP) software is an e-business, industrial-strength, server for mission-critical applications. It is a layer of middleware that integrates all the basic software services required by OLTP applications together with a rich set of resources and management services in a highly available, reliable, and scalable manner, enabling its customers to concentrate on the tasks relevant to their particular business.

COBOL (Common business-oriented language)

An English-like programming language for business data processing applications.

Cold Start

The standard initialization sequence performed by the TIBCO z/OS Substation initialization program. In a cold start, all resource definitions are refreshed. Resources dynamically installed or changed by the operations or XML Interface in a previous execution are lost.

COMMAREA (Communication area)

A CICS area that is used to pass data between tasks that communicate with a given terminal. The area can also pass data between programs within a task.

Console

An input-output device on a computer, reserved for communication between the computer operator or maintenance engineer and the computer.

Coupling Facility

A special logical partition that provides high-speed caching, list processing, and locking functions in a sysplex.

DCB (Data Control Block)

An MVS control block used by access method routines in storing and retrieving data.

DCUI (Data Configuration User Interface)

The user interface in which data transformation are configured.

DPL (Distributed Link Request)

A facility that enables a CICS client program to call a server program running in a remote CICS region and to pass and receive data using a communications area.

Dump

A representation of the contents of selected areas of the main storage that finds out whether a program is functioning as intended. A dump might serve as a helpful resource for analyzing problems.

ECB (Event Control Block)

An MVS or VSE control block that represents the status of an event.

ESTAE (Extended Specify Task Abnormal Exit)

A recovery routine to which the system passes control when an error occurs in the mainline routine. The recovery routine’s objective is to intercept the error and potentially perform one or more tasks.

EXCI (External CICS Interface) (CICS Transaction Server only)

A CICS application programming interface that helps make CICS applications more easily accessible than non-CICS environments.

Function

A specific purpose of an entity or its characteristic action.

GTF (Generalized Trace Facility)

In MVS, a trace data-collection routine. GTF traces the following system events: seek addresses on START I/O records, SRM activity, page faults, I/O activity, and supervisor services. Execution options specify the system events to be traced.

Heuristic Decision

A decision that enables a transaction manager to complete a failed in-doubt unit of work (UOW) that cannot wait for re synchronization after recovery from the failure.

Under the two-phase commit protocol, the loss of the coordinator (or loss of connectivity) that occurs while a UOW is in doubt theoretically forces a participant in the UOW to wait forever for re-synchronization. While a subordinate waits in doubt, resources remain locked and, in CICS Transaction Server for z/OS, the failed UOW is shunted pending resolution.

IMS (Information Management System)

A database manager that allows access to data in DL/I databases. IMS provides for the arrangement of data in an hierarchical structure and a common access approach in application programs that manipulate IMS databases.

JCL (Job Control Language)

A control language that describes a job and its requirements to an operating system.

LUW (Logical Unit of Work)

A sequence of processing actions (database changes, for example) that must be completed before individual actions can be regarded as committed. When changes are committed (by successful completion of the LUW and recording of the syncpoint on the system log), they do not need to be backed out after a subsequent failure of the task or system. The end of an LUW is marked in a transaction by a syncpoint, issued either by the user program or by CICS/IMS at the end of task. In the absence of user syncpoints, the entire task is an LUW.

MPP (Message Processing Program)

A region for processing IMS messages.

MVS (Multiple Virtual Storage)

An operating system for processing systems consists of one or more mainframe processors.

Multitasking

Concurrent execution of application programs within a CICS region.

Multithreading

Use, by several transactions, of a single copy of an application program.

OTMA (Open Transaction Manager Access)

A transaction-based, connectionless client-server protocol in IMS. The simplified four layer model is often used in descriptions of UNIX networks. In the four layer model, OTMA is the process layer. In the Open Systems Interconnecting (OSI) model, OTMA is the session layer. It can be best to think of OTMA as a combined session and transport layer.

Parameter (ISO)

  • A variable that is given a constant value for a specified application and that can denote the application.
  • Data passed between programs or presented to a program at startup.

Pipe

A one-way communication path between a sending process and a receiving process.

RACF (Resource Access Control Facility)

An IBM program that provides for access control by identifying and verifying users to the system, authorizing access to protected resources, logging detected unauthorized attempts to enter the system, and logging detected accesses to protected resources.

Routine

A program or sequence of instructions called by a program. Typically, a routine has a general purpose and is frequently used.

RRS (Resource Recovery Service)

The z/OS system component that provides the services that a resource manager calls to protect resources. RRS is the z/OS system level syncpoint manager.

SAF (System Authorization Facility)

Part of the operating system and conditionally directs control to RACF, if RACF is present, or to a user-supplied processing routine, or both, when receiving a request from a resource manager.

Sysplex

A set of MVS systems communicating and cooperating with each other through certain multisystem hardware components and software services to process customer workloads. See also MVS system, parallel sysplex.

Transaction

A unit of application data processing (consisting of one or more application programs) initiated by a single request, often from a terminal. A transaction can require the initiation of one or more tasks for its execution.

UOW (Unit of Work)

A sequence of processing actions (database changes, for example) that must be completed before individual actions performed by a transaction can be regarded as committed. After changes are committed (by successful completion of the UOW and recording of the syncpoint on the system log), they become durable, and are not backed out in the event of a subsequent failure of the task or system.

UOW (In-doubt Work Unit)

In CICS and IMS, a piece of work that is pending during commit processing; if commit processing fails between the polling of subsystems and the decision to execute the commit, recovery processing must resolve the status of work units that is in doubt.

VSAM (Virtual Storage Access Method)

An access method for direct or sequential processing of fixed-and variable-length records on direct access devices.

XCF (Cross System Coupling facility)

A component of MVS that provides functions to support cooperation between authorized programs running within a sysplex.