- macro
- An instruction that when executed causes the execution of a predefined sequence
of instructions in the source language. The predefined sequence can be modified
by parameters in the macro. CICS RDM macros are assembler macros and are converted
by the assembler.
- macro temporary store (MTS)
- The SMP/E data set used to hold updated versions of macros that will
not be placed in a target system library. They are stored during APPLY processing
and deleted by ACCEPT or STORE processing.
- main storage
- (ISO)
Program-addressable storage from which instructions and data can be loaded
directly into registers for subsequent execution or processing.
- main storage database (MSDB)
- In IMS, a root-segment database that
resides in main storage and that can be accessed to a field level.
- maintain system history program (MSHP)
- A program used for automating
and controlling various installation, tailoring, and service activities for
a VSE system.
- maintenance point
- A CICSPlex SM address space (CMAS) that is responsible
for maintaining CICSPlex SM definitions in its data repository and distributing
them to other CMASs involved in the management of a CICSplex.
- major object descriptor block (MODB)
- In CICSPlex SM, a control
structure built by Kernel Linkage during initialization of a CICSPlex SM component
that contains a directory of all methods that make up that component. The
structure of the MODB is the same for all components.
- major object environment block (MOEB)
- In CICSPlex SM, a control
structure built by Kernel Linkage during initialization of a CICSPlex SM component
and pointed to by the MODB. MOEB stores information critical to a CICSPlex
SM component and anchors data used by the component. The structure of the
MOEB is unique to the component it supports.
- map
- In BMS, a format established
for a page or a portion of a page, or a set of screen format descriptions.
A map relates program variables to the positions in which their values appear
on a display device. A map contains other formatting information such as field
attributes. A map describes constant fields and their position on the display,
the format of input and output fields, the attributes of constant and variable
fields, and the symbolic names of variable fields.
- map definition
- Definition of the size, shape, position, potential content, and
properties of BMS map sets, maps, and fields within maps, by means of macros.
See also map set definition macro (DFHMSD), map definition macro (DFHMDI), and field definition macro (DFHMDF).
- map definition macro (DFHMDI)
- In BMS, a macro that defines a map
within the map set defined by the previous DFHMSD macro. map set definition macro (DFHMSD),
and field definition macro (DFHMDF).
- mapped conversation
- In advanced
program-to-program communications (APPC), a temporary connection between an
application program and an APPC session in which the system provides all the
information on how the data is formatted. See also basic conversation.
- mapping
- In BMS, the process of transforming field data to and
from its displayable form.
- map set
- In basic mapping support (BMS), one
or more maps combined in a map set. The effects of this combination are to
reduce the number of entries in the PPT, and to load simultaneously all maps
needed for one application.
- map set definition macro (DFHMSD)
- A macro that is used to define a set of BMS maps. See also Defining The Map Set.
- map set suffix
- In
BMS, a suffix relating different versions of a map set to different terminal
models or partitions. This allows you to format the same data differently
on different screen types, in response to the same programming request.
- master
- In a multi-MVS or VSE MRO XRF configuration, a region that issues
commands to dependent regions at takeover time. See also coordinator.
- master JVM
- A JVM that initializes and owns
the shared class cache. The master JVM externalizes its system heap to become
the shared class cache, and supplies the class loading paths needed to load
classes into it. The master JVM is not used to run applications.
- master terminal
- (1) The IMS logical terminal that has complete control of IMS resources
during online operations.
- (2) In CICS, the terminal at which a designated
operator is signed on.
- master terminal functions
- A set of functions that allow a user to dynamically control and alter the
operation of a CICS system.
- master terminal operator
- Any CICS operator authorized to use the master terminal functions transaction
(CEMT).
- MBO
- See message backout table (MBO).
- MCP
- See message control program (MCP).
- MCT
- See monitoring control table (MCT).
- MDT
- See modified data tag (MDT).
- message area
- In BMS, the area of a screen used to send instruction
messages to assist the operator in processing a transaction. This area should
be separate from the application data area to allow communication with the
operator, without disturbing the application data. The message area is normally
the bottom one or two lines of the screen.
- message backout
table (MBO)
- In the restart data set, a summary table that contains
an entry for each terminal for which logged or journaled message or message
resynchronization records were written to the restart data set. Data in this
table is available to user-written exit programs.
- message cache
- A temporary storage queue with a DATAID of DFHMxxxx, where xxxx is the
identification of a logical unit, into which CICS reads messages (for message-protected
tasks only) during emergency restart. A user-written enquiry program run after
emergency restart can read the contents of message caches. CICS does not read
or purge message caches.
- message control program (MCP)
- In ACF/TCAM, a specific implementation of an access method, including
I/O routines, buffering routines, activation and deactivation routines, service
facilities, and SNA support.
- message data set
- The
message data set is used principally to pass messages about the current state
of specific resources from the active system to the alternate system. It is
also used for the secondary surveillance signals of the active, alternate,
or both CICS systems, when the control data set is unavailable for this purpose,
either because the last write has not completed yet or because of I/O errors.
- message domain
- Major component of CICS. It is a repository for
CICS messages and it handles the sending of messages to transient data destinations
or to the console. It also provides an interface for returning the text of
a message to the caller.
- message performance option
- The improvement of ISC performance by eliminating syncpoint coordination between
the connected systems.
- message protection
- A recovery and
restart function provided by CICS. It logs input and output messages for VTAM
terminals and enables the messages to be recovered following a system failure.
- message routing
- A method used for building a logical message and
routing it to one or more terminals. The message is scheduled, for each designated
terminal, to be delivered as soon as the terminal is available to receive
messages, or at a specified time. Terminal operators who receive the message
use terminal operator paging commands to view it. A variety of operands on
the ROUTE command allow you flexibility when specifying the message destinations.
- message switching
- The process of receiving a message, storing
it, and forwarding it to its destination unaltered.
- Meta-Object
Facility (MOF)
- A standard for the definition of information models
and the subsequent mapping of these models to CORBA interfaces.
- mirror task
- CICS task that services incoming requests that specify a CICS mirror
transaction (CSMI, CSM1, CSM2, CSM3, CSM5, CPMI, CVMI, or a user-defined mirror
transaction identifier). For more information, see The Mirror Transaction & Transformer Program.
- mirror transaction
- CICS transaction that recreates a request that is function shipped
from one system to another, issues the request on the second system, and passes
the acquired data back to the first system.
- mismatch
- The situation
when CICS assigns an available TCB from the open TCB pool, the HP TCB pool
or the JVM pool to a request, when the TCB has the correct mode (J8, J9, H8
or L8) but the wrong attributes (for example, a different program name or
JVM profile from that specified by the request). The TCB can be reused but
its attributes must be changed. For J8 and J9 TCBs, this means that the JVM
must be re-initialized. See also steal.
- mixed traffic
- A function of the VTAM class of service facility. Different kinds of
traffic can be assigned to the same virtual route, and, by selecting appropriate
transmission priorities, undue session interference can be prevented.
- MLPA
- See modified link pack area (MLPA).
- MMDDYYYY (mmddyyyy)
- Month-month-day-day-year-year format of a date (for example 04281934 for 28
April 1934). This format can be specified in the DATFORM system initialization
parameter. For more information, see Specifying CICS
system initialization parameters.
- MODB
- See Major object descriptor block (MODB).
- mode
- (1) In SNA data communications, the set of rules
and protocols to be used for a session. See also session.
- (2) The processing state of an activity. An activity can be in an initial,
active, dormant (that is, waiting for an event), cancelling, or complete mode.
- modegroup
- A VTAM LOGMODE entry, which can specify (among other
things) the class of service required for a group of APPC sessions.
- modename
- The name of a modeset and of the corresponding modegroup.
- modeset
- In CICS, a group of APPC sessions. A modeset is linked by its
modename to a modegroup (VTAM LOGMODE entry) that defines the class of service
for the modeset.
- modified data tag (MDT)
- (1) An
indicator, associated with each input or output field in a displayed record,
that is automatically set on when data is typed into the field. The modified
data tag is maintained by the display file and can be used by the program
using the file.
- (2) In the attribute byte of each field in a BMS map,
a bit that determines whether the field should be transmitted on a READ MODIFIED
command (the command used by CICS for all except copy operations).
- modified link pack area (MLPA)
- An element of MVS/ESA virtual storage.
This area provides a temporary extension to the PLPA existing only for the
life of the current IPL. You can use this area to add or replace altered LPA-eligible
modules without having to recreate the LPA. See also pageable link pack area (PLPA).
- MOEB
- See Major object environment block (MOEB).
- MOF
- See Meta-Object Facility
- monitor
- A user-provided program that handles unexpected events
reported by FEPI.
- monitoring
- (1) The regular assessment of an
ongoing production system against defined thresholds to check that the system
is operating correctly. See also monitoring domain.
- (2) Running
a hardware or software tool to measure the performance characteristics of
a system.
- (3) Pertaining to the collection of performance data for
all user- and CICS-supplied transactions during online processing for later
offline analysis.
- monitoring control table (MCT)
- A CICS table for the exclusive use of, in CICS Transaction Server, the
monitoring domain, and in CICS/VSE, the monitoring facility. The MCT contains
definitions of user event monitoring points (EMPs). EMPs describe how user
data fields in the performance class records are to be manipulated at each
user EMP. See also event monitoring point (EMP).
- monitoring domain
- In CICS Transaction Server only, the CICS domain responsible for producing
performance information on each task. Note that CICS distinguishes between
monitoring and statistics, but IMS does not. See also monitoring.
- monitoring record
- Any of three types of task-related activity
record (performance, event, and exception) built by the CICS monitoring domain
in CICS Transaction Server. Monitoring records are available to the user for
accounting, tuning, and capacity planning purposes. See The classes of monitoring data: Overview for a description of the three
types of account class data that can be collected. See also performance class data. exception class data, and SYSEVENT class data.
- monitoring section
descriptor
- The section descriptor preceding each section of monitoring
data written to the journal file, and built at the beginning of each monitoring
buffer.
- monitoring section prefix
- A prefix that precedes each section
of monitoring data written to the journal. It is built in an area immediately
after the journal control area (JCA). CICS moves it to the journal buffer
immediately before the section descriptor.
- MRO
- See multiregion operation (MRO).
- MSDB
- See main storage database (MSDB).
- MSHP
- See maintain system history program (MSHP).
- MTS
- See macro temporary store (MTS).
- multi-MVS environment
- A physical processing system that is capable of operating more
than one MVS image. See also MVS image
- multiple
mirror situation
- A transaction condition that can arise in an
intercommunication environment. When a transaction accesses resources in more
that one remote system, the intercommunication component of CICS invokes a
mirror transaction in each system to execute requests for the application
program. When the application program reaches a syncpoint, the intercommunication
component exchanges syncpoint messages with those mirror transactions that
have not yet terminated (if any).
- Multiple Virtual
Storage (MVS)
- The primary operating system used on IBM mainframes.
This operating system manages large amounts of memory and disk space.
- Multiple Virtual Storage/Enterprise Systems Architecture (MVS/ESA)
- Renamed, and more commonly known as z/OS.
- multiprogramming
- The concurrent execution of two or more computer programs by a computer.
- multiregion operation (MRO)
- Communication between CICS systems
in the same processor without the use of SNA network facilities. This allows
several CICS systems in different regions to communicate with each other,
and to share resources such as files, terminals, temporary storage, and so
on. The systems must be in the same operating system; or, if the XCF access
method is used, in the same MVS sysplex. See also intersystem communication (ISC) and
CICSplex.
- multitasking (tasking)
- A mode of operation that provides for concurrent
performance or interleaved execution of two or more tasks.
- multithreading
- Use, by several transactions, of a single copy of an application
program. See also single threading.
- MVS
- See Multiple Virtual Storage (MVS).
- MVS/Data Facility Product (MVS/DFP)
- A major element of MVS, including
data access methods and data administration utilities.
- MVS/DFP
- See MVS/DFP.
- MVS/ESA
- See Multiple Virtual Storage/Enterprise Systems Architeture (MVS/ESA).
- MVS/ESA extended nucleus
- A major element of MVS/ESA virtual storage.
This area duplicates the MVS/ESA nucleus above the 16MB line. See also MVS/ESA nucleus.
- MVS/ESA nucleus
- A major element of
MVS/ESA virtual storage. This static storage area contains control programs
and key control blocks. The area includes the nucleus load module and is of
variable size, depending on the installation's configuration. The nucleus
is duplicated above the 16MB line as the MVS/ESA extended nucleus.
- MVS image
- A single occurrence of the MVS/ESA operating system that has
the ability to process work. See also multi-MVS environment, single-MVS environment.
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