- back-end (system)
- The CICS or IMS system in which existing applications
run. Equivalent to partner system. See also front-end (system).
- back-end transaction
- In synchronous transaction-to-transaction
communication, a transaction that is started by a front-end transaction.
- background partition
- An area of virtual storage in which programs
are executed under control of the system. By default, the partition has a
processing priority lower than any of the existing foreground partitions.
- backout
- (1) An operation that reverses all the changes made during
the current unit of recovery or unit of work. After the operation is complete,
a new unit of recovery or unit of work begins. See also commit.
- (2) The process of restoring to a previous state all or part of a
system. The process of removing all the updates against protected resources
such as files and DL/I databases performed by an application program that
either has terminated abnormally or was inflight at the time of a CICS or
MVS or VSE image failure. Backout can by done dynamically in the case of an
application abend, or during restart in the case of CICS or MVS or VSE failure.
- backup
- The process of making a copy of a data file that can be
used if the original file is destroyed.
- backup session
- The
session that replaces the failing primary extended recovery facility (XRF)
session between a terminal user and the active subsystem.
- backup
while open (BWO)
- A means of taking backups of VSAM files that
CICS is concurrently updating. Backups taken with this facility are accepted
as input by the CICSVR forward recovery program.
- backward recovery
- The process of restoring integrity to databases and other recoverable
resources following a failure.
- BAS
- See Business Application Services (BAS).
- base cluster
- In systems with VSAM, a key-sequenced or entry-sequenced
file over which one or more alternate indexes are built.
- based addressing
- A form of addressing in which a data description is associated
with a storage area by a variable address held in a separate pointer area.
This is implemented in COBOL by BLL cells and in VS COBOL II by the ADDRESS
special register.
- base locator for linkage (BLL)
- In DOS/VS and OS/VS COBOL, a mechanism used to address storage outside
the working storage of an application program.
- base map
- Normal BMS full-screen
map that can be used as a base for simulated windows. See also canned map and overlay map.
- base segment
- The portion of a RACF profile
that contains basic information needed to define a user, group, or resource
to RACF. Also called RACF segment.
- base state
- The state
of a terminal that is set by CICS in the absence of any instructions from
a user application program, and before CICS sends data to it. In this state,
the terminal behaves as an ordinary display device.
- basic conversation
- In APPC, a conversation between two programs in which the sending
program must construct generalized data stream (GDS) records for the receiving
program. See also mapped conversation.
- basic direct
access method (BDAM)
- An access method used to retrieve or update
particular blocks of a data set on a direct access device.
- basic mapping resource map (BMS map)
- A map controlling the display
of input and output data by describing where fields are to be positioned on
the screen and what display attributes they are to have. They are not needed
for text data output. Every BMS mapping command names a map that contains
formatting (mapping) instructions. Each map has two forms: physical and symbolic.
- basic mapping support (BMS)
- An interface between CICS and application
programs that formats input and output display data and routes multiple-page
output messages without regard for control characters used by various terminals.
- basic sequential access method (BSAM)
- An access method for storing
or retrieving data blocks in a continuous sequence, using either a sequential
access or a direct access device.
- Basic Telecommunications Access Method (BTAM)
- An access method
that permits read and write communication with remote devices.
- Basic Telecommunications Access Method-Extended Storage (BTAM-ES)
- An IBM supplied telecommunications access method that permits read and
write communication with remote devices.
- batch data interchange
- A program that is used to extend the facilities of CICS terminal
control to simplify further the handling of data streams in a network.
- batched repository-update facility
- A CICSPlex SM facility, invoked
from the CICSPlex SM end user interface, for the bulk application of CICSPlex
SM definitions to a CMAS data repository.
- batch
message processing program (BMP, BMP program)
- An IMS batch processing
program that has access to online databases and message queues. BMPs run online,
but like programs in a batch environment, they are started with job control
language (JCL).
- batch processing
- A method of running
a program or a series of programs in which one or more records (a batch) are
processed with little or no action from the user or operator.
- batch program
- A program that is processed in series with other programs and therefore
normally processes data without user interaction.
- BB
- See begin bracket (BB).
- BDAM
- See basic direct access method (BDAM).
- before image
- A record
of the contents of a data element before it is changed. Before images are
used to backout incomplete or incorrect changes in the event of a failure.
- begin bracket (BB)
- In SNA, an indicator defining the start of
a conversation. The value of the indicator (binary 1) in the request header
of the first request in the first chain of a bracket denotes the start of
a bracket. See also conditional end bracket (CEB), FMH-5.
- BID
- In SNA, a command used to request permission to initiate a bracket.
- binary digit (bit)
- The smallest unit of computer information,
which has two possible states that are represented by the binary digits 0
or 1.
- binary synchronous communication (BSC)
- Data transmission in which
synchronization of characters is controlled by timing signals generated at
the sending and receiving stations. See also SDLC.
- bind
- In SNA, a request to activate a session between two logical
units (LUs). See also unbind session (UNBIND).
- bind request
- A request
to establish a connection between systems.
- bind-time security
- In LU6.2 and MRO, the level of security applied when a request to establish
a session is received from, or sent to, a remote system. Used to verify that
the remote system is really the system it claims to be. Also known as session security. See also BIND, link security,
and user security.
- bit
- See binary digit (bit).
- bit map
- In
temporary storage, a control block used by intrapartition transient data to
show the VSAM control intervals (or BSAM tracks) that have been used and are
available. It is updated whenever a control interval or track is assigned
to or released from a destination.
- bits per inch (bpi)
- The density, measured in number of bits per inch, at which information
can be stored on magnetic tape.
- bits per second (bps)
- In serial transmission, the instantaneous bit speed with which a device
or channel transmits a character.
- BLL
- See base locator for linkage (BLL).
- blocking
- The process of combining two or more records into one
block. See also deblocking.
- block-level data sharing
- A kind of IMS data sharing that allows multiple subsystem access
to the same database, controlled by means of a lock manager. Sharing is at
the physical-block level for ISAM or OSAM databases and at the control-interval
level for VSAM databases.
- BMP
- See batch message processing program (BMP).
- BMP program
- See batch message processing program (BMP).
- BMS
- See basic mapping support (BMS).
- BMS map
- See basic mapping resource map (BMS map).
- BMS map definition
- The use of macros (DFHMSD, DFHMDI, and DFHMDF) to define the
size, shape, position, potential content, and properties of BMS map sets,
maps, and fields within maps.
- BMS message routing
- The routing of data to one or more terminals other than the originating terminal.
- BMS page building
- The building and display of multiple, logically-connected
pages of mapped or text data.
- BMS text building
- The
formatting of unmapped text data.
- BNN
- See boundary network node (BNN).
- bottleneck
- A place in the system where contention for a resource
is affecting performance.
- boundary network node (BNN)
- In SNA, a subarea node that provides protocol support for adjacent peripheral
nodes, for example, transforming network addresses to local addresses and
vice versa, and providing session-level support for these peripheral nodes.
In XRF, the point at which terminal sessions are switched from the failing
active system to the new active system. The communication controller (or,
in CICS/VSE, an XSWITCH mechanism) at the BNN must be able to operate in an
XRF configuration.
- bpi
- See bits per inch (bpi).
- bps
- See bits per second (bps).
- bracket
- In SNA, one or more chains of request
units and their responses, representing a complete transaction, exchanged
between two session partners.
- bracket protocol
- In SNA,
a protocol that prevents the interruption of a transaction between CICS and
a logical unit. A bracket can also delimit conversations between CICS and
the logical unit or merely the transmission of a series of data chains in
one direction. Bracket protocol is used when CICS communicates with specific
logical units.
- browse token
- Identifier of a particular
browse of BTS objects within a CICS region. The same token returned on a STARTBROWSE
command must be supplied on the corresponding GETNEXT and ENDBROWSE commands.
CICS discards it after the ENDBROWSE.
- BSAM
- See basic mapping support (BMS)
- BSC
- See binary synchronous communication (BSC).
- BTAM
- See basic telecommunications access method (BTAM).
- BTAM-ES
- See Basic Telecommunications Access Method-Extended Storage (BTAM-ES).
- BTS
- See CICS business transaction services (BTS).
- BTS activity
- One part of a process managed
by CICS BTS. Typically, an activity is part of a business transaction.
- BTS-set
- The set of CICS regions across which related BTS processes
and activities may execute.
- buffer
- A routine or a portion of storage used
to hold data temporarily in order to compensate for different speeds of data
flow or timings of events between one device or system and another.
- buffer address
- In 3270 data stream, the address of a location
in the character buffer (screen image).
- builder
- A module in CICS
that, in conjunction with other builders, makes the autoinstall process possible,
allows the terminal control table (TCT) to be changed dynamically on a running
CICS system, and reduces the times needed for warm and emergency restart on
systems that use autoinstall.
- built-in function
- In CICS, the field de-editing function provided by the EXEC CICS BIF DEEDIT
command. The BIF DEEDIT command removes alphabetic and special characters
from an EBCDIC data field, and right-justifies the remaining digits, padding
to the left with zeros as necessary.
- bulk loading
- A performance
feature of VS COBOL II that supports the loading of selected library routines
into the CICS region at CICS initialization time, or into the LPA at MVS initialization
time or SVA at VSE initialization time.
- business application
- Any set of CICS resources that represent a meaningful entity to an enterprise
or a user (such as Payroll).
- Business Application
Services (BAS)
- The component of CICSPlex SM that provides the
ability to define and manage business applications in terms of their CICS
resources and associated CICS systems. BAS provides a central definition repository
for CICS systems, complete with installation facilities and the ability to
restrict a CICSPlex SM request to those resources defined as being part of
the business application.
- business logic
- The
part of a distributed application that is concerned with the application logic
rather than the user interface of the application. See presentation logic.
- business transaction
- A self-contained business function, for example,
the booking of an airline ticket. Traditionally, in CICS a business transaction
might be implemented as multiple user transactions; the booking of the airline
ticket might be undertaken by transactions that inquire about availability,
reserve the seat, deal with payment, and print the ticket, for example. Using
BTS, a business transaction might be implemented as multiple activities.
- business transaction services
- An application programming interface
(API) and support services that allow users to manage complex busniess transactions.
See business transaction.
- BWO
- See backup while open (BWO).
- byte
- A string that represents a character and usually consists
of eight binary digits that are treated as a unit. A byte is the smallest
unit of storage that can be addressed directly.
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