Glossary of terms and abbreviations
This glossary defines WebSphere MQ terms and abbreviations used throughout the WebSphere MQ information
set. If you do not find the term you are looking for here, try the IBM(R) Dictionary of Computing, New York: McGraw-Hill, 1994.
If you believe that we have omitted a WebSphere MQ term from this glossary, please
use any of the methods described in Sending your comments
to IBM at the back of this book to tell us.
This glossary includes terms and definitions from the American National Dictionary for Information Systems , ANSI X3.172-1990,
copyright 1990 by the American National Standards Institute (ANSI). Copies
may be purchased from the American National Standards Institute, 11 West 42 Street,
New York, New York 10036. Definitions are identified by the symbol (A) after
the definition.
A: B: C: D: E: F: G: H: I: J: K: L: M: N: O: P: Q: R: S: T: U: V: W: X: Y: Z
A
-
abend reason code
- A 4-byte hexadecimal
code that uniquely identifies a problem with a program that runs on a z/OS(R) or OS390 operating system.
-
abstract class
- An object-oriented
programming class that represents a concept; classes derived from it represent
implementations of the concept. An object cannot be constructed from an abstract
class; that is, it cannot be instantiated. See also parent class.
-
access control
- In computer security,
the process of ensuring that only authorized users can access the resources
of a computer system in authorized ways.
-
access control list (ACL)
- In computer
security, a list associated with an object that identifies all the subjects
that can access the object and their access rights. For example, an access
control list is a list that is associated with a file that identifies the
users who can access the file and that identified the user's access rights
to that file.
-
accountability
- The quality of being
responsible for one's actions.
-
ACL
- See access
control list.
-
active log
- See recovery log.
-
adapter
- An interface between WebSphere(R) MQ for z/OS and TSO, IMS(TM), CICS(R), or batch address spaces. An adapter
is an attachment facility that enables applications to access WebSphere MQ services.
-
address space
- The area of virtual
storage available for a particular job.
-
administration bag
- In the WebSphere MQ Administration
Interface (MQAI), a type of data bag that is created for administering WebSphere MQ by implying that it can change the order of data items,
create lists, and check selectors within a message.
-
administrator command
- A command used
to manage WebSphere MQ objects, such as queues, processes, and namelists.
-
Advanced Program-to-Program Communication (APPC)
- An implementation of the SNA LU 6.2 protocol that allows interconnected
systems to communicate and share the processing of programs.
-
affinity
- An association between objects
that have some relationship or dependency upon each other.
-
alert
- A message sent to a management
services focal point in a network to identify a problem or an impending problem.
-
alert monitor
- In WebSphere MQ for z/OS, a component of the CICS adapter that handles unscheduled events occurring
as a result of connection requests to WebSphere MQ for z/OS.
-
alias queue object
- A WebSphere MQ object,
the name of which is an alias for a base queue defined to the local queue
manager. When an application or a queue manager uses an alias queue, the alias
name is resolved and the requested operation is performed on the associated
base queue.
-
allied address space (ally)
- A z/OS address space that is connected to WebSphere MQ for z/OS.
-
ally
- See allied
address space.
-
alternate user authority
- The ability
of a user ID to supply a different user ID for security checks. When an application
opens a WebSphere MQ object, it can supply a user ID on the MQOPEN or MQPUT1
call that the queue manager uses for authority checks instead of the one associated
with the application.
-
alternate user security
- On z/OS, the authority
checks that are performed when an application requests alternate user authority
when opening a WebSphere MQ object.
-
APAR
- See authorized
program analysis report.
-
API-crossing exit
- A user written
program that is similar in concept to an API exit. It is supported only for CICS applications on WebSphere MQ for z/OS.
-
API exit
- A user-written program that
monitors or modifies the function of an MQI call. For each MQI call issued
by an application, the API exit is invoked before the queue manager starts
to process the call and again after the queue manager has completed processing
the call. The API exit can inspect and modify any of the parameters on the
MQI call.
-
APPC
- See Advanced
Program-to-Program Communication.
-
application-defined format
- Application
data in a message for which the user application defines the meaning. See
also built-in format.
-
application environment
- The software
facilities that are accessible by an application program. On the z/OS platform, CICS and IMS are examples of application environments.
-
application level security
- The security
services that are invoked when an application issues an MQI call.
-
application log
- In Windows(R) systems,
a log that records significant application events.
-
application queue
- A local queue which,
when it has triggering set on and when the triggering conditions are met,
requires that trigger messages are written.
-
archive log
- See recovery log.
-
ARM
- See automatic
restart manager.
-
asymmetric key cryptography
- A system
of cryptography that uses two keys: a public key known to everyone and a private
key known only to the receiver or sender of the message. See also public-private key, symmetric key cryptography.
-
asynchronous messaging
- A method of
communication between programs in which a program places a message on a message
queue, then proceeds with its own processing without waiting for a reply to
its message. See also synchronous messaging.
-
attribute
- (1) In object oriented programming,
a property of an object or class that can be distinguished distinctly from
any other properties. Attributes often describe state information.
- (2) A characteristic or trait of an entity that describes the entity; for
example, the telephone number of an employee is one of that employee's attributes.
An attribute may have a type, which indicates the range of information given
by the attribute, and a value, which is within that range. In XML, for example,
an attribute consists of a name-value pair within a tagged element, that modifies
features of the element.
-
authentication
- The security service
that provides proof that a user of a computer system is genuinely who that
person claims to be. Common mechanisms for implementing this service are passwords
and digital signatures. Authentication is distinct from authorization; authentication
is not concerned with granting or denying access to system resources.
-
authority check
- See authorization check.
-
authorization
- The process of granting
or denying access to a network resource. Security systems use a two-step process:
after authentication has verified that a user is who she says she is, authorization
allows the user access to various resources based on the user's identity.
-
authorization check
- A security check
that is performed when a user or application attempts to access a system resource;
for example, when an administrator attempts to issue a command to administer WebSphere MQ or when an application attempts to connect to a queue manager.
Authorization checks are also known as authority checks and are performed
as part of the access control security service.
-
authorization file
- In WebSphere MQ on UNIX(R) systems, a file that provides security definitions for an object,
a class of objects, or all classes of objects.
-
authorization service
- In WebSphere MQ on UNIX systems and WebSphere MQ for Windows, a service that provides authority
checking of commands and MQI calls for the user identifier associated with
the command or call.
-
authorized program analysis report (APAR)
- A request for correction of a defect in a current release of an IBM-supplied
program.
-
automatic restart manager (ARM)
- A z/OS recovery function that can improve the availability of specific
batch jobs or started tasks, and therefore result in faster resumption of
productive work.
B
-
backout
- 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.
-
bag
- See data
bag.
-
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.
-
behavior
- In object-oriented programming,
the functionality embodied within a method.
-
BMS
- See basic
mapping support.
-
Booch methodology
- An object-oriented
methodology that helps users design systems using the object-oriented paradigm.
-
bootstrap data set (BSDS)
- A VSAM
data set that contains an inventory of all active and archived log data sets
known to WebSphere MQ for z/OS, and a wrap-around inventory of all recent WebSphere MQ for z/OS activity. The BSDS is required to restart the WebSphere MQ for z/OS subsystem.
-
browse
- In message queuing, to use
the MQGET call to copy a message without removing it from the queue.
-
browse cursor
- In message queuing,
an indicator used when browsing a queue to identify the message that is next
in sequence.
-
BSDS
- See bootstrap
data set.
-
buffer pool
- An area of main storage
used for WebSphere MQ for z/OS queues, messages, and object definitions.
See also page set.
-
built-in format
- Application data
in a message for which the queue manager defines the meaning. See also application-defined format.
C
-
CA
- See certificate
authority.
-
call back
- In WebSphere MQ, a
requester message channel initiates a transfer from a sender channel by first
calling the sender, then closing down and awaiting a call back.
-
CCF
- See channel
control function.
-
CCSID
- See coded character set identifier.
-
CDF
- See channel
definition file.
-
certificate authority (CA)
- A trusted
third-party organization or company that issues the digital certificates used
to create digital signatures and public-private key pairs. The certificate
authority guarantees that the individual granted the unique certificate is,
in fact, who she claims to be. The role of the CA is to authenticate the entities
(individuals or organizations) involved in electronic transactions. CAs are
a critical component in data security and electronic commerce because they
guarantee that the two parties exchanging information are really who they
claim to be.
-
certificate revocation list
- A list
of certificates that have been revoked before their scheduled expiration date.
CRLs are maintained by the certification authority and used, during SSL handshaking,
to ensure that the certificates involved have not been revoked.
-
certificate store
- The Windows name
for a key repository.
-
CFStruct
- A WebSphere MQ object
used to describe the queue manager's use of a Coupling Facility list structure
-
channel control function (CCF)
- A
program to move messages from a transmission queue to a communication link,
and from a communication link to a local queue, together with an operator
panel interface to allow the setup and control of channels.
-
channel definition file (CDF)
- A file
containing communication channel definitions that associate transmission queues
with communication links.
-
channel event
- An event reporting
conditions detected during channel operations, such as when a channel instance
is started or stopped. Channel events are generated on the queue managers
at both ends of the channel.
-
channel exit program
- A user-written
program that is called from one of a defined number of places in the processing
sequence of a message channel agent (MCA).
-
channel initiator
- A component of WebSphere MQ distributed queuing that monitors the initiation queue to
see when triggering criteria have been met and then starts the sender channel.
-
channel listener
- A component of WebSphere MQ distributed queuing that monitors the network for a startup
request and then starts the receiving channel.
-
checkpoint
- A place in a program at
which a check is made, or at which a recording of data is made to allow the
program to be restarted in case of interruption.
-
CI
- See control
interval.
-
CipherSpec
- The combination of encryption
algorithm and hash function applied to an SSL message after authentication
completes.
-
cipher suite
- The combination of authentication,
key exchange algorithm, and CipherSpec used by SSL for secure exchange of
data.
-
ciphertext
- Data that has been encrypted.
Ciphertext is unreadable until it has been converted into plaintext (decrypted)
with a key. See also plaintext.
-
circular logging
- In WebSphere MQ on UNIX systems and WebSphere MQ for Windows, the process of keeping all restart
data in a ring of log files. See also linear logging.
-
CL
- See Command
Language.
-
class
- In object-oriented design or
programming, a model or template that can be used to create objects with a
common definition and common properties, operations, and behavior. An object
is an instance of a class.
-
class hierarchy
- The relationships
between classes that share a single inheritance. In Java(TM) programming, all classes inherit from
the Object class.
-
class library
- In object-oriented
programming, a collection of prewritten classes or coded templates, any of
which can be specified and used by a programmer when developing an application.
-
client
- A run-time component that
provides access to queuing services on a server for local user applications.
The queues used by the applications reside on the server. See also WebSphere MQ client.
-
client application
- An application,
running on a workstation and linked to a client, that gives the application
access to queuing services on a server.
-
client connection channel type
- The
type of MQI channel definition associated with a WebSphere MQ client.
See also server connection channel type.
-
CLUSRCVR
- See cluster-receiver channel.
-
CLUSSDR
- See cluster-sender channel.
-
cluster
- (1) In Microsoft(R) Cluster
Server, a group of computers, connected together and configured in such a
way that, if one fails, MSCS performs a failover, transferring the state data
of applications from the failing computer to another computer in the cluster
and reinitiating their operation there.
- (2) In WebSphere MQ, a
group or two or more queue managers on one or more computers, providing automatic
interconnection, and allowing queues to be shared amongst them for load balancing
and redundancy.
-
cluster queue
- A queue that is hosted
by a cluster queue manager and made available to other queue managers in the
cluster.
-
cluster queue manager
- A queue manager
that is a member of a cluster. A queue manager can be a member of more than
one cluster.
-
cluster-receiver channel (CLUSRCVR)
- A channel on which a cluster queue manager can receive messages from other
queue managers in the cluster, and cluster information from the repository
queue managers.
-
cluster-sender channel (CLUSSDR)
- A channel on which a cluster queue manager can send messages to other queue
managers in the cluster, and cluster information to the repository queue managers.
-
cluster transmission queue
- A transmission
queue that holds all messages from a queue manager destined for another queue
manager that is in the same cluster. The queue is called SYSTEM.CLUSTER.TRANSMIT.QUEUE.
-
coded character set identifier (CCSID)
- The name of a coded set of characters and their code point assignments.
-
command
- In WebSphere MQ, an
administration instruction that can be carried out by the queue manager.
-
command bag
- In the MQAI, a type of
bag that is created for administering WebSphere MQ objects, but cannot change the
order of data items or create lists within a message.
-
Command Language (CL)
- In WebSphere MQ for iSeries(TM), a language that can be used to issue commands, either at the command
line or by writing a CL program.
-
command prefix (CPF)
- In WebSphere MQ for z/OS, a character string that identifies the queue manager to which WebSphere MQ for z/OS commands are directed, and from which WebSphere MQ for z/OS operator messages are received.
-
command processor
- The WebSphere MQ component
that processes commands.
-
command server
- The WebSphere MQ component
that reads commands from the system-command input queue, verifies them, and
passes valid commands to the command processor.
-
commit
- An operation that applies
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 backout.
-
completion code
- A return code indicating
how a message queue interface (MQI) call has ended.
-
confidentiality
- The security service
that protects sensitive information from unauthorized disclosure. Encryption
is a common mechanism for implementing this service.
-
configuration event
- Notifications
about the attributes of an object. The notifications are generated when the
object is created, changed, or deleted and also by explicit requests.
-
configuration file
- In WebSphere MQ on UNIX systems and WebSphere MQ for iSeries, a file that contains configuration
information for logs, communications, or installable services. See also stanza.
-
connect
- The means by which an application
gains access to a queue manager and its resources.
-
connection handle
- The identifier
or token by which a program accesses the queue manager to which it is connected.
-
constructor
- In object-oriented programming,
a special method used to initialize an object.
-
context
- Information about the originator
of a message that is held in fields in the message descriptor. There are two
categories of context information: identity context and origin context. Context
is also known as message context.
-
context security
- On z/OS, the authority
checks that are performed when an application opens a queue and specifies
that it will set the context in messages that it puts on the queue, or pass
the context from messages that it has received to messages that it puts on
the queue.
-
control command
- In WebSphere MQ on UNIX systems and WebSphere MQ for Windows, a command that can be entered
interactively from the operating system command line. Such a command requires
only that the WebSphere MQ product be installed; it does not require
a special utility or program to run it.
-
control interval (CI)
- A fixed-length
area of direct access storage in which VSAM stores records and creates distributed
free space. The control interval is the unit of information that VSAM transmits
to or from direct access storage. A control interval always includes an integral
number of physical records.
-
controlled shutdown
- See quiesced shutdown. See also immediate shutdown, preemptive shutdown.
-
coupling facility
- On z/OS, a special
logical partition that provides high-speed caching, list processing, and locking
functions in a parallel sysplex.
-
CPF
- See command
prefix.
-
cross-system coupling facility (XCF)
- A component of OS/390(R) that provides functions to support cooperation between
authorized programs running within a Parallel Sysplex(R).
-
cryptography
- Protecting information
by transforming it (encrypting it) into an unreadable format, called ciphertext.
Only those who possess a secret key can decipher (or decrypt) the message
into plaintext.
D
-
DAE
- See dump
analysis and elimination.
-
daemon
- A program that runs unattended
to perform continuous or periodic functions, such as network control.
-
data bag
- A container of object properties
that the MQAI uses in administering queue managers. There are three types
of data bag: user (for user data), administration (for administration with
assumed options), and command (for administration with no options assumed).
-
data conversion interface (DCI)
- TheWebSphere MQ interface to which customer- or vendor-written programs that
convert application data between different machine encodings and CCSIDs must
conform. A part of the WebSphere MQ Framework.
-
data-conversion service
- A service
that converts application data to the character set and encoding that are
required by applications on other platforms.
-
datagram
- A form of asynchronous messaging
in which an application sends a message, but does not require a response.
-
data integrity
- The security service
that detects whether there has been unauthorized modification of data, or
tampering. The service detects only whether data has been modified; it does
not restore data to its original state if it has been modified.
-
data item
- In the MQAI, an item contained
within a data bag. This can be an integer item or a character-string item,
and a user item or a system item.
-
DCE principal
- A user ID that uses
the distributed computing environment.
-
DCI
- See data
conversion interface.
-
DCM
- See Digital
Certificate Manager.
-
dead-letter queue
- A queue to which
a queue manager or application sends messages that cannot be delivered to
their correct destination.
-
dead-letter queue handler
- A WebSphere MQ-supplied
utility that monitors a dead-letter queue (DLQ) and processes messages on
the queue in accordance with a user-written rules table.
-
decryption
- The process of decoding
data that has been encrypted into a secret format. Decryption requires a secret
key or password.
-
default object
- A definition of an
object (for example, a queue) with all attributes defined. If a user defines
an object but does not specify all possible attributes for that object, the
queue manager uses default attributes in place of any that were not specified.
-
deferred connection
- A pending event
that is activated when a CICS subsystem tries to connect to WebSphere MQ for z/OS before it has started.
-
derivation
- In object-oriented programming,
the refinement or extension of one class from another.
-
digital certificate
- An electronic
document used to identify an individual, server, company, or some other entity,
and to associate a public key with the entity. A digital certificate is issued
by a certification authority and is digitally signed by that authority.
-
Digital Certificate Manager (DCM)
- On OS/400(R) systems, the method of managing digital certificates and using
them in secure applications on the iSeries server. Digital Certificate Manager
requests and processes digital certificates from certification authorities
(CAs) or other third-parties.
-
digital signature
- Information that
is encrypted with a private key and is appended to a message to assure the
recipient of the authenticity and integrity of the message. The digital signature
proves that the message was signed by the entity that owns, or has access
to, the private key or shared secret symmetric key.
-
distinguished name
- A set of name-value
pairs (such as CN=person's name and C=country or region) that uniquely identify
an entity in a digital certificate.
-
distributed application
- In message
queuing, a set of application programs that can each be connected to a different
queue manager, but that collectively comprise a single application.
-
Distributed Computing Environment
- In network computing, a set of services and tools that supports the creation,
use, and maintenance of distributed applications across heterogeneous platforms.
DCE is independent of the operating system and network. DCE was developed
by the Open Software Foundation (OSF) and is typically used in a larger network
of computing systems.
-
distributed queue management
- In message
queuing, the setup and control of message channels to queue managers on other
systems.
-
distribution list
- A list of queues
to which a message can be put using a single MQPUT or MQPUT1 statement.
-
dual logging
- A method of recording WebSphere MQ for z/OS activity, where each change is recorded on two data
sets, so that if a restart is necessary and one data set is unreadable, the
other can be used. See also single logging.
-
dual mode
- See dual logging. See also single logging.
-
dump analysis and elimination (DAE)
- A z/OS service that enables an installation to suppress SVC dumps and ABEND
SYSUDUMP dumps that are not needed because they duplicate previously written
dumps.
-
dynamic queue
- A local queue created
when a program opens a model queue object.
E
-
eavesdropping
- A breach of communication
security in which the information remains intact, but its privacy is compromised.
See also impersonation, tampering.
-
encapsulation
- In object-oriented
programming, the technique that is used to hide the inherent details of an
object, function, or class from client programs. Client programs are only
required to know the interface of a class (the signatures of the methods of
the class and the names of the attributes of the class) to use the methods
and attributes of the class.
-
encryption
- In computer security,
the process of transforming data into an unintelligible form in such a way
that the original data either cannot be obtained or can be obtained only by
using a decryption process.
-
enqueue
- To put a message on a queue.
-
environment variable
- A variable that
specifies how an operating system or another program runs, or the devices
that the operating system recognizes.
-
ESM
- See external
security manager.
-
ESTAE
- See extended specify task abnormal exit.
-
event data
- In an event message, the
part of the message data that contains information about the event (such as
the queue manager name, and the application that gave rise to the event).
See also event header.
-
event header
- In an event message,
the part of the message data that identifies the event type of the reason
code for the event. See also event data.
-
event message
- A message that contains
information (such as the category of event, the name of the application that
caused the event, and queue manager statistics) relating to the origin of
an instrumentation event in a network of WebSphere MQ systems.
-
event queue
- The queue onto which
the queue manager puts an event message after it detects an event. Each category
of event (queue manager, performance, configuration, instrumentation, or channel
event) has its own event queue.
-
Event Viewer
- A tool provided by Windows systems to examine and manage log files.
-
exclusive method
- In object-oriented
programming, a method that is not intended to exhibit polymorphism; one with
specific effect.
-
extended specify task abnormal exit (ESTAE)
- A z/OS macro that provides recovery capability and gives control to the
user-specified exit routine for processing, diagnosing an abend, or specifying
a retry address.
-
external security manager (ESM)
- A security product that performs security checking on users and resources. RACF(R) is an example of an ESM.
F
-
failover
- An operation in which Microsoft Cluster Server detects a failure in an application on one computer
in the cluster, and shuts down the disrupted application in an orderly manner,
transfers its state data to the other computer, and re-initiates the application
there.
-
FAP
- See Formats
and Protocols.
-
FFST(TM) file
- See First Failure Support Technology(TM) file.
-
FIFO
- See first-in-first-out.
-
First Failure Support
Technology file (FFST file)
- A file containing information for
use in detecting and diagnosing software problems. In WebSphere MQ, FFST files have a file type of FDC.
-
first-in-first-out (FIFO)
- A queuing
technique in which the next item to be retrieved is the item that has been
in the queue for the longest time.
-
forced shutdown
- A type of shutdown
of the CICS adapter where the adapter immediately disconnects from WebSphere MQ for z/OS, regardless of the state of any currently active tasks. See also quiesced shutdown.
-
format
- In message queuing, a term
used to identify the nature of application data in a message.
-
Formats and Protocols (FAP)
- In message
queuing, a definition of how queue managers communicate with each other, and
of how clients communicate with server queue managers.
-
Framework
- In WebSphere MQ, a
collection of programming interfaces that allow customers or vendors to write
programs that extend or replace certain functions provided in WebSphere MQ products.
The interfaces are the following: data conversion interface (DCI), message
channel interface (MCI), name service interface (NSI), security enabling interface
(SEI), trigger monitor interface (TMI).
-
friend class
- In object-oriented programming,
a class in which all the member functions are granted access to the private
and protected members of another class. It is named in the declaration of
another class and uses the keyword friend as a prefix to the class.
-
FRR
- See functional
recovery routine.
-
full repository
- A complete set of
information about every queue manager in a cluster. This set of information
is called the repository or sometimes the full repository and is usually held
by two of the queue managers in the cluster. See also partial repository.
-
function
- A named group of statements
that can be called and evaluated and can return a value to the calling statement.
-
functional recovery routine (FRR)
- A z/OS recovery and termination manager that enables a recovery routine
to gain control in the event of a program interrupt.
G
-
generalized trace facility (GTF)
- An optional z/OS service program that records significant system events, such as
supervisor calls and start I/O operations, for the purpose of problem determination.
-
Generic Security Services Application Programming
Interface (GSS API)
- A common application programming interface
(API) for accessing security services.
-
get
- In message queuing, to use the
MQGET call to remove a message from a queue.
-
globally defined object
- On z/OS, an object
whose definition is stored in the shared repository. The object is available
to all queue managers in the queue-sharing group. See also locally defined object.
-
global trace
- A WebSphere MQ for z/OS trace option where the trace data comes from the entire WebSphere MQ for z/OS subsystem.
-
GSS API
- See Generic Security Services Application Programming Interface.
-
GTF
- See generalized
trace facility.
H
-
handshake
- The exchange of messages
at the start of a Secure Sockets Layer session that allows the client to authenticate
the server using public key techniques (and, optionally, for the server to
authenticate the client), then allows the client and server to cooperate in
creating symmetric keys for encryption, decryption, and detection of tampering.
-
hardened message
- A message that is
written to auxiliary (disk) storage so that the message is not lost in the
event of a system failure.
-
heartbeat
- In software products, a
signal that one entity sends to another to convey that it is still active.
-
heartbeat flow
- A pulse that is passed
from a sending message channel agent (MCA) to a receiving MCA when there
are no messages to send. The pulse unblocks the receiving MCA, which would
otherwise remain in a wait state until a message arrived or the disconnect
interval expired.
-
heartbeat interval
- The time, in seconds,
that is to elapse between heartbeat flows.
I
-
ICE
- See Intersystem
Communications Environment.
-
identification
- The security service
that enables each user of a computer system to be identified uniquely. A common
mechanism for implementing this service is to associate a user ID with each
user.
-
IFCID
- See instrumentation facility component identifier.
-
ILE
- See Integrated Language Environment(R).
-
immediate shutdown
- In WebSphere MQ, a
shutdown of a queue manager that does not wait for applications to disconnect.
Current message queue interface (MQI) calls are allowed to complete, but new
MQI calls fail after an immediate shutdown has been requested. See also controlled shutdown, preemptive
shutdown.
-
impersonation
- A breach of communication
security in which the information is passed to a person posing as the intended
receiver or information is sent by a person posing as someone else. See also eavesdropping, tampering.
-
inbound channel
- A channel that receives
messages from another queue manager.
-
in-built format
- See built-in format. See also application-defined format.
-
index
- In the WebSphere MQ Administration
Interface (MQAI), a means of referencing data items.
-
in-doubt unit of recovery
- In WebSphere MQ, the status of a unit of recovery for which a syncpoint
has been requested but not yet confirmed.
-
inheritance
- An object-oriented programming
technique that allows the use of existing classes as a basis for creating
other classes.
-
initialization input data set
- A data
set used by WebSphere MQ for z/OS when it starts up.
-
initiation queue
- A local queue on
which the queue manager puts trigger messages.
-
input parameter
- A parameter of an
MQI call in which you supply information when you make the call.
-
insertion order
- In the WebSphere MQ Administration
Interface (MQAI), the order that data items are placed into a data bag.
-
installable service
- In WebSphere MQ on UNIX systems and WebSphere MQ for Windows, additional functionality provided
as independent component. The installation of each component is optional:
in-house or third-party components can be used instead.
-
instance
- In C, an object.
-
instance data
- In object-oriented
programming, state information associated with an object.
-
instrumentation event
- A way of monitoring
queue manager resource definitions, performance conditions, and channel conditions
in a network of WebSphere MQ systems.
-
instrumentation facility component identifier
(IFCID)
- In DB2 Universal Database(TM) for z/OS and OS/390, a value
that names and identifies a trace record of an event that can be traced. As
a parameter on the START TRACE and MODIFY TRACE commands, it specifies that
the corresponding event is to be traced.
-
Integrated Language Environment (ILE)
- A set of constructs and interfaces that provides a
common run-time environment and run-time bindable application program interfaces
(APIs) for all ILE-conforming high-level languages.
-
Interactive Problem Control System (IPCS)
- A component of MVS(TM) and z/OS that permits online problem management,
interactive problem diagnosis, online debugging for disk-resident abend dumps,
problem tracking, and problem reporting.
-
Interactive System Productivity Facility (ISPF)
- An IBM licensed program that serves as a full-screen editor
and dialog manager. Used for writing application programs, it provides a means
of generating standard screen panels and interactive dialogs between the application
programmer and terminal user. ISPF consists of four major components: DM,
PDF, SCLM, and C/S. The DM component is the DialogManager, which provides
services to dialogs and end-users. The PDF component is the ProgramDevelopment
Facility, which provides services to assist the dialog or application developer.
The SCLM component is the Software Configuration Library Manager, which provides
services to applicationdevelopers to manage their application development
libraries. The C/S component is the Client/Server, which allows you to run
ISPF on programmable workstation, to display the panels using the displayfunction
of your workstation operating system, and to integrate workstation tools and
data with host toolsand data.
-
interface
- In object-oriented programming,
an abstract model of behavior; a collection of functions or methods.
-
Internet Protocol (IP)
- A protocol
that routes data through a network or interconnected networks. Internet Protocol
(IP) acts as an intermediary between the higher protocol layers and the physical
network. See also Transmission Control Protocol.
-
interprocess communication (IPC)
- The process by which programs communicate data to each other and synchronize
their activities. Semaphores, signals, and internal message queues are common
methods of interprocess communication.
-
intersystem communication (ISC)
- A CICS facility that provides inbound and outbound support for communication
from other computer systems.
-
Intersystem Communications Environment (ICE)
- A family of Compaq-based software products that enables you to
access a variety of applications on Compaq computers.
-
IP
- See Internet
Protocol.
-
IPC
- See interprocess
communication.
-
IPCS
- See Interactive
Problem Control System.
-
ISC
- See intersystem
communication.
-
ISPF
- See Interactive
System Productivity Facility.
J
-
Java Runtime Environment (JRE)
- A subset of the Sun Microsystems Java Development Kit (JDK) that contains
the core executable programs and files that constitute the standard Java platform.
The JRE includes the Java virtual machine (JVM), core classes,
and supporting files.
-
journal
- A feature of OS/400 that WebSphere MQ for iSeries uses to control updates to local objects. Each
queue manager library contains a journal for that queue manager.
-
JRE
- See Java Runtime Environment.
K
-
Kerberos
- An authentication system
developed at the Massachusetts Institute of Technology (MIT) that enables
two parties to exchange private information over an otherwise open network.
It works by assigning a unique key, called a ticket, to each user that logs
on to the network. The ticket is then embedded in messages that are sent over
the network. The receiver of a message uses the ticket to authenticate the
sender.
-
key authentication
- See authentication.
-
key repository
- A store for digital
certificates and their associated private keys.
-
key ring
- z/OS name for a key repository.
L
-
LDAP
- See Lightweight
Directory Access Protocol.
-
Lightweight Directory Access Protocol (LDAP)
- An open protocol that uses TCP/IP to provide access to directories
that support an X.500 model and that does not incur the resource requirements
of the more complex X.500 Directory Access Protocol (DAP). For example, LDAP
can be used to locate people, organizations, and other resources in an Internet
or intranet directory.
-
linear logging
- In WebSphere MQ on UNIX systems, and WebSphere MQ for Windows, the process of keeping restart
data in a sequence of files. New files are added to the sequence as necessary.
The space in which the data is written is not reused. See also circular logging.
-
link level security
- The security
services that are invoked, directly or indirectly, by a message channel agent
(MCA), the communications subsystem, or a combination of the two working together.
-
listener
- A program that detects incoming
requests and starts the associated channel.
-
local definition of a remote queue
- A WebSphere MQ object belonging to a local queue manager that defines the
attributes of a queue that is owned by another queue manager. In addition,
it is used for queue-manager aliasing and reply-to-queue aliasing.
-
locale
- On UNIX systems, a subset of a user's environment
that defines conventions for a specific culture (such as time, numeric, or
monetary formatting and character classification, collation, or conversion).
The queue manager CCSID is derived from the locale of the user ID that created
the queue manager.
-
locally defined object
- On z/OS, an object
whose definition is stored on page set zero. The definition can be accessed
only by the queue manager that defined it. See also globally defined object.
-
local queue
- A queue that belongs
to the local queue manager. A local queue can contain a list of messages waiting
to be processed. See also remote queue.
-
local queue manager
- The queue manager
to which the program is connected. and that provides message queuing services
to the program. A queue manager to which a program is not connected is called
a remote queue manager, even if it is running on the same system as the program.
See also remote queue manager.
-
log
- In WebSphere MQ, a
file recording the work done by queue managers while they receive, transmit,
and deliver messages, to enable them to recover in the event of failure.
-
log control file
- In WebSphere MQ on UNIX systems, and WebSphere MQ for Windows, the file containing information
needed to monitor the use of log files (for example, their size and location,
and the name of the next available file).
-
log file
- In WebSphere MQ on UNIX systems, and WebSphere MQ for Windows, a file in which all significant
changes to the data controlled by a queue manager are recorded. If the primary
log files become full, WebSphere MQ allocates secondary log files.
-
logical unit (LU)
- In SNA, a port
or window through which a user accesses the SNA network to communicate with
another user, and uses the functions provided by system services control points
(SSCPs). An LU can support at least two sessions--one with an SSCP and one
with another LU--and may be capable of supporting many sessions with other
LUs.
-
logical unit 6.2
- (1) A type of logical
unit that supports general communications between programs in a distributed
processing environment. LU 6.2 is characterized by (a) a peer relationship
between session partners, (b) efficient use of a session for multiple transactions,
(c) comprehensive end-to-end error processing, and (d) a generic application
programming interface (API) consisting of structured verbs that are mapped
into a product implementation.
- (2) The LU type that supports sessions
between two applications using APPC.
-
logical unit of work identifier (LUWID)
- A name (consisting of a fully qualified LU network name, a logical-unit-of-work
(LUW) instance number, and an LUW sequence number) that uniquely identifies
a logical unit of work within a network.
-
log record sequence number (LRSN)
- An alternative technique to RBA for addressing log records.
-
LRSN
- See log
record sequence number.
-
LU
- See logical
unit.
-
LU 6.2 conversation
- In SNA, a logical
connection between two transaction programs over an LU 6.2 session that enables
them to communicate with each other.
-
LU 6.2 conversation level security
- In SNA, a conversation level security protocol that enables a partner transaction
program to authenticate the transaction program that initiated the conversation.
LU 6.2 conversation level security is also known as end user verification.
-
LU 6.2 session
- In SNA, a session
between two logical units (LUs) of type 6.2.
-
LU name
- In a z/OS or OS/390 environment,
the name by which VTAM(R) refers to a node in a network. See also logical unit.
-
LUWID
- See logical unit of work identifier.
M
-
marshaling
- See serialization.
-
MCA
- See message
channel agent.
-
MCI
- See message
channel interface.
-
media image
- In WebSphere MQ on UNIX systems and WebSphere MQ for Windows, the sequence of log records that
contain an image of an object. The object can be re-created from this image.
-
message
- (1) A communication sent from
a person or program to another person or program.
- (2) In system programming,
information intended for the terminal operator or system administrator.
-
message channel
- In distributed message
queuing, a mechanism for moving messages from one queue manager to another.
A message channel comprises two message channel agents (a sender at one end
and a receiver at the other end) and a communication link.
-
message channel agent (MCA)
- A program
that transmits prepared messages from a transmission queue to a communication
link, or from a communication link to a destination queue. See also Message Queue Interface.
-
message channel interface (MCI)
- The WebSphere MQ interface to which customer- or vendor-written programs
that transmit messages between a WebSphere MQ queue manager and another messaging
system must conform. A part of the WebSphere MQ Framework.
-
message descriptor
- Control information
describing the message format and presentation that is carried as part of
a WebSphere MQ message. The format of the message descriptor is defined
by the MQMD structure.
-
message exit
- A type of channel exit
program that is used to modify the contents of a message. Message exits usually
work in pairs, one at each end of a channel. At the sending end of a channel,
a message exit is called after the message channel agent (MCA) has got a message
from the transmission queue. At the receiving end of a channel, a message
exit is called before the message channel agent (MCA) puts a message on its
destination queue.
-
message flow control
- A distributed
queue management task that involves setting up and maintaining message routes
between queue managers.
-
Message Format Service (MFS)
- An editing
facility that allows application programs to deal with simple logical messages
instead of device-dependent data, thus simplifying the application development
process.
-
message group
- A group of logical
messages. Logical grouping of messages allows applications to group messages
that are similar and to ensure the sequence of the messages.
-
message input descriptor (MID)
- The
MFS control block that describes the format of the data presented to the application
program. See also message output descriptor.
-
message output descriptor (MOD)
- The MFS control block that describes the format of the output data produced
by the application program. See also message input descriptor.
-
message priority
- In WebSphere MQ, an
attribute of a message that can affect the order in which messages on a queue
are retrieved, and whether a trigger event is generated.
-
Message Queue Interface (MQI)
- The
programming interface provided by WebSphere MQ queue managers. The programming
interface allows application programs to access message queuing services.
See also message channel
agent.
-
message queue management (MQM)
- In MQSeries(R) for Compaq NonStop Kernel, a facility that provides access to
PCF command formats and control commands to manage queue managers, queues,
and channels.
-
message queuing
- A programming technique
in which each program within an application communicates with the other programs
by putting messages on queues.
-
message-retry
- An option available
to an MCA that is unable to put a message. The MCA can wait for a predefined
amount of time and then try to put the message again.
-
message segment
- One of a number of
segments of a message that is too large either for the application or for
the queue manager to handle.
-
message sequence numbering
- A programming
technique in which messages are given unique numbers during transmission over
a communication link. This enables the receiving process to check whether
all messages are received, to place them in a queue in the original order,
and to discard duplicate messages.
-
method
- In object-oriented design
or programming, the software that implements the behavior specified by an
operation.
-
MFS
- See Message
Format Service.
-
Microsoft Cluster Server (MSCS)
- A technology that provides high availability by grouping computers into
MSCS clusters. If one of the computers in the cluster hits any one of a range
of problems, MSCS shuts down the disrupted application in an orderly manner,
transfers its state data to another computer in the cluster, and re-initiates
the application there.
-
Microsoft Transaction Server (MTS)
- A facility that helps Windows users run business logic applications
in a middle tier server. MTS divides work up into activities, which are short
independent chunks of business logic.
-
MID
- See message
input descriptor.
-
MOD
- See message
output descriptor.
-
model queue object
- A set of queue
attributes that act as a template when a program creates a dynamic queue.
-
MQAI
- See WebSphere MQ Administration Interface.
-
MQI
- See Message
Queue Interface.
-
MQI channel
- A connection between
a WebSphere MQ client and a queue manager on a server system. An MQI channel
transfers only MQI calls and responses in a bidirectional manner.
-
MQM
- See message
queue management.
-
MQSC
- See WebSphere MQ script commands.
-
MQSeries
- A previous name for WebSphere MQ.
-
MSCS
- See Microsoft Cluster Server.
-
MTS
- See Microsoft Transaction Server.
-
multi-hop
- To pass through one or
more intermediate queue managers when there is no direct communication link
between a source queue manager and the target queue manager.
N
-
namelist
- A WebSphere MQ object
that contains a list of names, for example, queue names.
-
name service
- In WebSphere MQ on UNIX systems and WebSphere MQ for Windows, the facility that determines
which queue manager owns a specified queue.
-
name service interface (NSI)
- The WebSphere MQ interface to which customer- or vendor-written programs
that resolve queue-name ownership must conform. A part of the WebSphere MQ Framework.
-
name transformation
- In WebSphere MQ on UNIX systems and WebSphere MQ for Windows, an internal process that changes
a queue manager name so that it is unique and valid for the system being used.
Externally, the queue manager name remains unchanged.
-
nested bag
- In the WebSphere MQ Administration
Interface (MQAI), a system bag that is inserted into another data bag
-
nesting
- In the WebSphere MQ Administration
Interface (MQAI), a means of grouping information returned from WebSphere MQ.
-
NetBIOS (Network Basic Input/Output System)
- A standard interface to networks, and personal computers that is used
on local area networks to provide message, print-server, and file-server functions.
Application programs that use NetBIOS do not need to handle the details of
LAN data link control (DLC) protocols.
-
Network Basic Input/Output System
- See NetBIOS.
-
New Technology File System (NTSF)
- A Windows recoverable file system that provides security for files.
-
node
- In Microsoft Cluster
Server (MSCS), each computer in the cluster.
-
nonpersistent message
- A message that
does not survive a restart of the queue manager. See also persistent message.
-
NSI
- See name
service interface.
-
NTSF
- See New
Technology File System.
-
NUL
- See null
character.
-
null character (NUL)
- The character
hex 00 used to represent the absence of a displayed or printed character.
O
-
OAM
- See object
authority manager.
-
object
- (1) In WebSphere MQ, a
queue manager, a queue, a process definition, a channel, a namelist, authentication
information object, or a storage class (z/OS only).
- (2) In object-oriented
design or programming, a concrete realization (instance) of a class that consists
of data and the operations associated with that data. An object contains the
instance data that is defined by the class, but the class owns the operations
that are associated with the data.
-
object authority manager (OAM)
- In WebSphere MQ on UNIX systems, WebSphere MQ for iSeries, and WebSphere MQ for Windows, the default authorization service
for command and object management. The OAM can be replaced by, or run in combination
with, a customer-supplied security service.
-
object descriptor
- A data structure
that identifies a particular WebSphere MQ object. Included in the descriptor
are the name of the object and the object type.
-
object handle
- The identifier or token
by which a program accesses the WebSphere MQ object with which it is working.
-
object-oriented programming
- A programming
approach based on the concepts of data abstraction and inheritance. Unlike
procedural programming techniques, object-oriented programming concentrates
not on how something is accomplished but instead on what data objects comprise
the problem and how they are manipulated.
-
offloading
- In WebSphere MQ for z/OS, an automatic process whereby a queue manager's active log is transferred
to its archive log.
-
open systems interconnection (OSI)
- The interconnection of open systems in accordance with standards of the International
Organization for Standardization (ISO) for the exchange of information.
-
Open Transaction Manager Access (OTMA)
- A component of IMS that implements a transaction-based, connectionless
client/server protocol in an MVS sysplex environment. The domain of the
protocol is restricted to the domain of the MVS Cross-System Coupling Facility (XCF). OTMA
connects clients to servers so that the client can support a large network
(or a large number of sessions) while maintaining high performance.
-
OPM
- See original
program model.
-
original program model (OPM)
- The
set of functions for compiling source code and creating high-level language
programs on the system before the Integrated Language Environment (ILE) model was introduced.
-
OSI
- See open
systems interconnection.
-
OSI directory standard
- The standard,
known as X.500, that defines a comprehensive directory service, including
an information model, a namespace, a functional model, and an authentication
framework. X.500 also defines the Directory Access Protocol (DAP) used by
clients to access the directory. The Lightweight Directory Access Protocol
(LDAP) removes some of the burden of X.500 access from directory clients,
making the directory available to a wider variety of machines and applications.
-
OTMA
- See Open
Transaction Manager Access.
-
outbound channel
- A channel that takes
messages from a transmission queue and sends them to another queue manager.
-
output log-buffer
- In WebSphere MQ for z/OS, a buffer that holds recovery log records before they are written to
the archive log.
-
output parameter
- A parameter of an
MQI call in which the queue manager returns information when the call completes
or fails.
-
overloading
- The existence of more
than one flavor of method with the same name or operator, but with different
signatures, within a class. The name or operator remains the same, but the
method parameters differ, with each signature requiring a separate implementation.
Such methods usually exhibit the same behavior, despite differences in signature.
P
-
page set
- A VSAM data set used when WebSphere MQ for z/OS moves data (for example, queues and messages) from
buffers in main storage to permanent backing storage (DASD). See also buffer pool.
-
parent class
- A class from which another
class inherits instance methods, attributes, and instance variables. See also abstract class.
-
partial repository
- A partial set
of information about queue managers in a cluster. A partial repository is
maintained by all cluster queue managers that do not host a full repository.
See also full repository.
-
PCF
- See programmable
command format.
-
pending event
- An unscheduled event
that occurs as a result of a connect request from a CICS adapter.
-
percolation
- In error recovery, the
passing along a preestablished path of control from a recovery routine to
a higher-level recovery routine.
-
performance event
- A category of event
indicating that a limit condition has occurred.
-
performance trace
- A WebSphere MQ trace
option where the trace data is to be used for performance analysis and tuning.
-
permanent dynamic queue
- A dynamic
queue that is deleted when it is closed only if deletion is explicitly requested.
Permanent dynamic queues are recovered if the queue manager fails, so they
can contain persistent messages. See also temporary
dynamic queue.
-
persistent message
- A message that
survives a restart of the queue manager. See also nonpersistent
message.
-
ping
- The command that sends an Internet
Control Message Protocol (ICMP) echo-request packet to a gateway, router,
or host with the expectation of receiving a reply.
-
PKI
- See public
key infrastructure.
-
plaintext
- In cryptography, any message
that is not encrypted. See also ciphertext.
-
platform
- In WebSphere MQ, the
operating system under which a queue manager is running.
-
point of recovery
- In WebSphere MQ for z/OS, a set of backup copies of WebSphere MQ for z/OS page sets and the corresponding log data
sets required to recover these page sets. These backup copies provide a potential
restart point in the event of page set loss (for example, page set I/O error).
-
polymorphism
- An object-oriented programming
characteristic that allows a method to perform differently, depending on the
class that implements it. Polymorphism allows a subclass to override an inherited
method without affecting the parent class's method. Polymorphism also enables
a client to access two or more implementations of an object from a single
interface.
-
preemptive shutdown
- In WebSphere MQ, a
shutdown of a queue manager that does not wait for connected applications
to disconnect, or for current MQI calls to complete. See also controlled shutdown, immediate shutdown.
-
preferred computer
- The primary computer
used by an application running under Microsoft Cluster Server control. After
a failover to another computer, MSCS monitors the preferred computer until
it is repaired, and as soon as it is running correctly again, moves the application
back to it.
-
principal
- In WebSphere MQ on UNIX systems and WebSphere MQ for Windows, a term used for a user identifier.
Used by the object authority manager for checking authorizations to system
resources.
-
privately defined object
- See locally defined object. See also globally defined
object.
-
private methods and instance data
- In object-oriented programming, methods and instance data that are only accessible
to the implementation of the same class.
-
process definition object
- A WebSphere MQ object
that contains the definition of a WebSphere MQ application. For example, a queue
manager uses the definition when it works with trigger messages.
-
programmable command format (PCF)
- A type of WebSphere MQ message used by the following applications:
user administration applications, to put PCF commands onto the system command
input queue of a specified queue manager, user administration applications,
to get the results of a PCF command from a specified queue manager, and a
queue manager, as a notification that an event has occurred. See also WebSphere MQ script commands.
-
program temporary fix (PTF)
- For zSeries(R), iSeries, and pSeries(R) products, a fix that is made available
to all customers. A program temporary fix is tested by IBM. It contains
a PTF record.
-
protected methods and instance data
- In object-oriented programming, methods and instance data that are only accessible
to the implementations of the same or derived classes, or from friend classes.
-
PTF
- See program
temporary fix.
-
public key cryptography
- A cryptography
system that uses two keys: a public key known to everyone and a private or
secret key known only to the recipient of the message. The public and private
keys are related in such a way that only the public key can be used to encrypt
messages and only the corresponding private key can be used to decrypt them.
-
public key infrastructure (PKI)
- A system of digital certificates, certification authorities, and other registration
authorities that verify and authenticate the validity of each party involved
in an Internet transaction.
-
public methods and instance data
- In object oriented programming, methods and instance data that are accessible
to all classes.
-
public-private key
- A cryptography
system that uses two keys: a public key known to everyone and a private or
secret key known only to the recipient of the message. The public and private
keys are related in such a way that only the public key can be used to encrypt
messages and only the corresponding private key can be used to decrypt them.
See also asymmetric key cryptography, symmetric key cryptography.
Q
-
queue
- A WebSphere MQ object
to which message queuing applications can put messages, and from which they
can get messages. Local queues can contain a list of messages waiting to
be processed. Queues of other types cannot contain messages: they point to
other queues, or can be used as models for dynamic queues.
-
queue manager
- (1) A system program that
provides queuing services to applications. It provides an application programming
interface so that programs can access messages on the queues that the queue
manager owns.
- (2) An object that defines the attributes of a particular
queue manager.
-
queue manager event
- An event that
indicates one of the following: an error condition has occurred in relation
to the resources used by a queue manager. For example, a queue is unavailable,
or a significant change has occurred in the queue manager. For example, a
queue manager has stopped or started.
-
queue manager level security
- In WebSphere MQ for z/OS, the authorization checks that are performed using RACF profiles specific to a queue manager.
-
queue-sharing group
- In WebSphere MQ for z/OS, a group of queue managers in the same sysplex that can access a single
set of object definitions stored in the shared repository, and a single set
of shared queues stored in the coupling facility. See also shared queue.
-
queue-sharing group level security
- In WebSphere MQ for z/OS, the authorization checks that are performed using RACF profiles that are shared by all queue managers in a queue-sharing group.
-
quiesced shutdown
- (1) A type of shutdown
of the CICS adapter where the adapter disconnects from WebSphere MQ, but
only after all the currently active tasks have been completed. See also forced shutdown.
- (2) In WebSphere MQ, a
shutdown of a queue manager that allows all connected applications to disconnect.
See also immediate shutdown, preemptive shutdown.
-
quiescing
- In WebSphere MQ, the
state of a queue manager before it stops. In this state, programs are allowed
to finish processing, but no new programs are allowed to start.
-
quorum disk
- The disk accessed exclusively
by Microsoft Cluster Server to store the cluster recovery
log, and to determine whether a server is up or down. Only one server can
own the quorum disk at a time. Servers in the cluster can negotiate for the
ownership.
R
-
RACF
- See Resource Access Control Facility.
-
RAID
- See Redundant
Array of Independent Disks.
-
RBA
- See relative
byte address.
-
reason code
- A return code that describes
the reason for the failure or partial success of a Message Queue Interface
(MQI) call.
-
receive exit
- A type of channel exit
program that is called just after the message channel agent (MCA) has regained
control following a communications receive and has received a unit of data
from a communications connection. See also send exit.
-
receiver channel
- In message queuing,
a channel that responds to a sender channel, takes messages from a communication
link, and puts them on a local queue.
-
recovery log
- In WebSphere MQ for z/OS, data sets containing information needed to recover messages, queues,
and the WebSphere MQ subsystem. WebSphere MQ for z/OS writes each record to a data set called
the active log. When the active log is full, its contents are off-loaded to
a DASD or tape data set called the archive log.
-
recovery termination manager (RTM)
- A program that handles all normal and abnormal termination of tasks by passing
control to a recovery routine associated with the terminating function.
-
Redundant Array of Independent Disks (RAID)
- A collection of two or more disk physical drives that present to the
host an image of one or more logical disk drives. In the event of a single
physical device failure, the data can be read or regenerated from the other
disk drives in the array due to data redundancy.
-
reference message
- A message that
refers to a piece of data that is to be transmitted. The reference message
is handled by message exit programs, which attach and detach the data from
the message so allowing the data to be transmitted without having to be stored
on any queues.
-
registry
- In a Microsoft Windows operating system, a database that contains system configuration
information regarding the user, the hardware, and the programs and applications
that are installed. Windows operating systems refer to the
registry during operation.
-
Registry Editor
- In Windows,
the program item that allows the user to edit the registry.
-
registry hive
- In Windows systems,
the structure of the data stored in the registry.
-
relative byte address (RBA)
- The offset
of a data record or control interval from the beginning of the storage space
that is allocated to the data set or file to which it belongs.
-
remote queue
- A queue that belongs
to a remote queue manager. Programs can put messages on remote queues, but
they cannot get messages from remote queues. See also local queue.
-
remote queue manager
- To a program,
a queue manager that is not the one to which the program is connected. See
also local queue manager.
-
remote queue object
- A WebSphere MQ object
belonging to a local queue manager. This object defines the attributes of
a queue that is owned by another queue manager. In addition, it is used for
queue-manager aliasing and reply-to-queue aliasing.
-
remote queuing
- In message queuing,
the provision of services to enable applications to put messages on queues
belonging to other queue managers.
-
reply message
- A type of message used
for replies to request messages. See also report message, request message.
-
reply-to queue
- The name of a queue
to which the program that issued an MQPUT call wants a reply message or report
message sent.
-
report message
- A type of message
that gives information about another message. A report message can indicate
that a message has been delivered, has arrived at its destination, has expired,
or could not be processed for some reason. See also reply message, request message.
-
repository
- A collection of information
about the queue managers that are members of a cluster. This information includes
queue manager names, their locations, their channels, what queues they host,
and so on.
-
repository queue manager
- A queue
manager that hosts the full repository of information about a cluster.
-
requester channel
- In message queuing,
a channel that can be started locally to initiate operation of a server channel.
See also server channel.
-
request message
- A type of message
used to request a reply from another program. See also reply message, report message.
-
request/reply
- A type of messaging
application in which a request message is used to request a reply from another
application.
-
RESLEVEL
- In WebSphere MQ for z/OS, an option that controls the number of CICS user IDs checked for API-resource security.
-
resolution path
- The set of queues
that are opened when an application specifies an alias or a remote queue on
input to an MQOPEN call.
-
resource
- Any facility of a computing
system or operating system required by a job, task, or executing program.
Resources include main storage, input/output devices, the processing unit,
data sets, files, libraries, folders, and control or processing programs.
In WebSphere MQ for z/OS, examples of resources are buffer pools, page sets,
log data sets, queues, and messages.
-
Resource Access Control Facility (RACF)
- An IBM licensed program that provides access control by identifying users
to the system; verifying users of the system; authorizing access to protected
resources; logging detected, unauthorized attempts to enter the system; and
logging detected accesses to protected resources.
-
resource manager
- An application,
program, or transaction that manages and controls access to shared resources
such as memory buffers and data sets. WebSphere MQ, CICS, and IMS are resource managers.
-
Resource Recovery Services (RRS)
- A z/OS facility that provides two-phase sync point support across participating
resource managers.
-
responder
- In distributed queuing,
a program that replies to network connection requests from another system.
-
resynch
- In WebSphere MQ, an
option to direct a channel to start up and resolve any in-doubt status messages,
but without restarting message transfer.
-
return code
- The collective name for
completion codes and reason codes.
-
return-to-sender
- An option available
to an MCA that is unable to deliver a message. The MCA can send the message
back to the originator.
-
Rivest-Shamir-Adleman algorithm (RSA)
- A public-key encryption technology developed by RSA Data Security, Inc,
and used in our implementation of SSL. The acronym stands for Rivest, Shamir,
and Adelman, the inventors of the technique.
-
rollback
- See backout. See also commit.
-
RRS
- See Resource
Recovery Services.
-
RSA
- See Rivest-Shamir-Adleman
algorithm.
-
RTM
- See recovery
termination manager.
-
rules table
- A control file containing
one or more rules that the dead-letter queue handler applies to messages on
the dead letter queue (DLQ).
S
-
SAF
- See System
Authorization Facility.
-
Scalable Parallel 2 (SP2)
- IBM's parallel UNIX system: effectively parallel AIX(R) systems on a high-speed network.
-
SDK
- See software
development kit.
-
SDWA
- See system
diagnostic work area.
-
SECMEC
- See security mechanism.
-
Secure Sockets Layer
- A security protocol
that provides communication privacy. SSL enables client/server applications
to communicate in a way that is designed to prevent eavesdropping, tampering,
and message forgery.
-
security enabling interface (SEI)
- The WebSphere MQ interface to which customer- or vendor-written programs
that check authorization, supply a user identifier, or perform authentication
must conform. A part of theWebSphere MQ Framework.
-
security exit
- A channel exit program
that is called immediately after the initial data negotiation has completed
on channel startup. Security exits normally work in pairs and can be called
on both message channels and MQI channels. The primary purpose of the security
exit is to enable the message channel agent (MCA) at each end of a channel
to authenticate its partner.
-
security identifier
- On Windows systems,
a supplement to the user ID that identifies the full user account details
on the Windows security account manager database where the
user is defined.
-
security mechanism (SECMEC)
- A technical
tool or technique that is used to implement a security service. A mechanism
might operate by itself, or in conjunction with others, to provide a particular
service. Examples of security mechanisms include access control lists, cryptography,
and digital signatures.
-
security message
- One of the messages,
sent by security exits that are called at both ends of a channel, to communicate
with each other. The format of a security message is not defined and is determined
by the user.
-
security service
- A service within
a computer system that protect its resources. Access control is an example
of a security service.
-
Security Support Provider Interface (SSI)
- The means for networked applications to call one of several security
support providers (SSPs) to establish authenticated connections and to exchange
data securely over those connections. It is available for use on Windows systems.
-
SEI
- See security
enabling interface.
-
selector
- An identifier for a data
item. In the WebSphere MQ Administration Interface (MQAI), there are
two types of selector: a user selector and a system selector.
-
semaphore
- In UNIX systems,
a general method of communication between two processes that extends the features
of signals.
-
sender channel
- In message queuing,
a channel that initiates transfers, removes messages from a transmission queue,
and moves them over a communication link to a receiver or requester channel.
-
send exit
- A type of channel exit
program that is called just before a message channel agent (MCA) issues a
communications send to send a unit of data over a communications connection.
See also receive exit.
-
Sequenced Packet Exchange protocol (SPX)
- A session-oriented network protocol that provides connection-oriented
services between two nodes on the network, and is used primarily by client/server
applications. It relies on the Internet Packet Exchange (IPX) protocol, provides
flow control and error recovery, and guarantees reliability of the physical
network.
-
sequence number wrap value
- In WebSphere MQ, a method of ensuring that both ends of a communication
link reset their current message sequence numbers at the same time. Transmitting
messages with a sequence number ensures that the receiving channel can reestablish
the message sequence when storing the messages.
-
serialization
- In object-oriented
programming, the writing of data in sequential fashion to a communications
medium from program memory.
-
server
- (1) In WebSphere MQ, a
queue manager that provides queue services to client applications running
on a remote workstation.
- (2) In a network, hardware or software that
provides facilities to other stations. For example, a file server, a printer
server, or a mail server. The station making the request of the server is
usually called the client. See also client.
-
server channel
- In message queuing,
a channel that responds to a requester channel, removes messages from a transmission
queue, and moves them over a communication link to the requester channel.
See also requester channel.
-
server connection channel type
- The
type of MQI channel definition associated with the server that runs a queue
manager. See also client connection channel type.
-
service interval
- A time interval,
against which the elapsed time between a put or a get and a subsequent get
is compared by the queue manager in deciding whether the conditions for a
service interval event have been met. The service interval for a queue is
specified by a queue attribute.
-
service interval event
- An event related
to the service interval.
-
session
- A logical or virtual connection
between two stations, programs, or devices on a network that allows the two
elements to communicate and exchange data, or the activities that occur during
the establishment, maintenance, and release of the connection. A session
can be activated and deactivated as requested.
-
session ID
- In WebSphere MQ for z/OS, the CICS-unique identifier that defines the communication link to be
used by a message channel agent when moving messages from a transmission queue
to a link.
-
session level authentication
- In Systems
Network Architecture (SNA), a session level security protocol that enables
two logical units (LUs) to authenticate each other while they are activating
a session. Session level authentication is also known as LU-LU verification.
-
session level cryptography
- In Systems
Network Architecture (SNA), a method of encrypting and decrypting data that
flows on a session between two logical units (LUs).
-
shared inbound channel
- In WebSphere MQ for z/OS, a channel that was started by a listener using the group port. The
channel definition of a shared channel can be stored either on page set zero
(private) or in the shared repository (global).
-
shared outbound channel
- In WebSphere MQ for z/OS, a channel that moves messages from a shared transmission queue. The
channel definition of a shared channel can be stored either on page set zero
(private) or in the shared repository (global).
-
shared queue
- In WebSphere MQ for z/OS, a type of local queue. The messages on the queue are stored in the
coupling facility and can be accessed by one or more queue managers in a queue-sharing
group. The definition of the queue is stored in the shared repository. See
also queue-sharing group.
-
shared repository
- In WebSphere MQ for z/OS, a shared DB2(R) database that is used to hold object definitions that
have been defined globally.
-
shell
- A software interface between
users and the operating system that interprets commands and user interactions
and communicates them to the operating system. A computer may have several
layers of shells for various levels of user interaction.
-
signal
- In UNIX systems a simple method of communicating
between two processes. One process can inform the other when an event occurs.
-
signaling
- In WebSphere MQ for z/OS and WebSphere MQ for Windows, a feature that allows the operating
system to notify a program when an expected message arrives on a queue.
-
signature
- The collection of types
associated with a method (the type of the return value, if any, as well as
the number, order, and type of each of the method's arguments).
-
single logging
- A method of recording WebSphere MQ for z/OS activity where each change is recorded on one data
set only. See also dual logging.
-
single-phase backout
- A method in
which an action in progress must not be allowed to finish, and all changes
that are part of that action must be undone.
-
single-phase commit
- A method in which
a program can commit updates to a commitment resource without coordinating
those updates with updates the program has made to resources controlled by
another resource manager. See also two-phase commit.
-
SIT
- See system
initialization table.
-
SMF
- See System
Management Facility.
-
SNA
- See Systems
Network Architecture.
-
software development kit (SDK)
- A
set of tools, APIs, and documentation to assist with the development of software
in a specific computer language or for a particular operating environment.
-
source queue manager
- See local queue manager. See also remote queue manager.
-
SP2
- See Scalable
Parallel 2.
-
SPX
- See Sequenced
Packet Exchange protocol.
-
SSI
- See Security
Support Provider Interface.
-
stanza
- A group of lines in a configuration
file that assigns a value to a parameter modifying the behavior of a queue
manager, client, or channel. In WebSphere MQ on UNIX systems a configuration (.ini) file
can contain a number of stanzas. See also configuration
file.
-
star-connected communications network
- A network in which all nodes are connected to a central node.
-
storage class
- In WebSphere MQ for z/OS, the page set that is to hold the messages for a particular queue. The
storage class is specified when the queue is defined.
-
store and forward
- The temporary storing
of packets, messages, or frames in a data network before they are retransmitted
toward their destination.
-
streaming
- In object-oriented programming,
the serialization of class information and object instance data.
-
subsystem
- In z/OS, a service
provider that performs one or many functions, but does nothing until asked.
For example, each WebSphere MQ for z/OS queue manager is a z/OS subsystem.
-
supervisor call (SVC)
- An instruction
that interrupts the program being run and passes control to the supervisor
so that it can perform the specific service indicated by the instruction.
-
SVC
- See supervisor
call.
-
switch profile
- In WebSphere MQ for z/OS, a RACF profile used when WebSphere MQ starts up or when a refresh security
command is issued. Each switch profile that WebSphere MQ detects turns off checking for
the specified resource.
-
symmetric key cryptography
- A system
of cryptography in which the sender and receiver of a message share a single,
common, secret key that is used to encrypt and decrypt the message. See also public-private key, asymmetric
key cryptography.
-
symptom string
- Diagnostic information
displayed in a structured format designed for searching the IBM software support
database.
-
synchronous messaging
- A method of
communication between programs in which a program places a message on a message
queue and then waits for a reply to its message before resuming its own processing.
See also asynchronous messaging.
-
sync point
- An intermediate or end
point during processing of a transaction at which the transaction's protected
resources are consistent. At a syncpoint, changes to the resources can safely
be committed, or they can be backed out to the previous syncpoint.
-
SYS1.LOGREC
- A service aid that contains
important information about program and hardware errors.
-
sysplex
- See system complex.
-
System Authorization Facility (SAF)
- A z/OS facility through with programs communicate with an external security
manager such as RACF.
-
system bag
- A type of data bag that
is created by the MQAI.
-
system complex (sysplex)
- A set of MVS or OS/390 systems communicating and cooperating with each other through certain
multisystem hardware components and software services to process customer
workloads.
-
system control commands
- Commands
used to manipulate platform-specific entities such as buffer pools, storage
classes, and page sets.
-
system diagnostic work area (SDWA)
- In a z/OS or OS/390 environment, the data that is recorded in a SYS1.LOGREC
entry that describes a program or hardware error.
-
system initialization table (SIT)
- A table containing parameters used by CICS on start up.
-
system item
- A type of data item that
is created by the MQAI.
-
System Management Facility (SMF)
- A z/OS facility that collects and records a variety of system and job-related
information. For example, statistics, accounting information, and performance
data.
-
system selector
- In the WebSphere MQ Administration
Interface (MQAI), a system item identifier that is included in the data bag
when it is created.
-
Systems Network Architecture (SNA)
- An architecture that describes the logical structure, formats, protocols,
and operational sequences for transmitting information units through the networks
and also the operational sequences for controlling the configuration and operation
of networks. The layered structure of SNA allows the ultimate origins and
destinations of information (the users) to be independent of and unaffected
by the specific SNA network services and facilities that are used for information
exchange.
T
-
tampering
- A breach of communication
security in which information in transit is changed or replaced and then sent
on to the recipient. See also eavesdropping, impersonation.
-
target library high-level qualifier (thlqual)
- A high-level qualifier for z/OS target data set names.
-
target queue manager
- See remote queue manager. See also local queue manager.
-
task control block (TCB)
- A z/OS control block
used to communicate information about tasks, within an address space, that
are connected to a z/OS subsystem such as WebSphere MQ for z/OS or CICS.
-
task switching
- The overlapping of
I/O operations and processing between several tasks. In WebSphere MQ for z/OS, the task switcher optimizes performance by allowing some MQI calls
to be executed under subtasks rather than under the main CICS TCB.
-
TCB
- See task
control block.
-
TCP
- See Transmission
Control Protocol.
-
TCP/IP
- See Transmission Control Protocol/Internet Protocol.
-
temporary dynamic queue
- A dynamic
queue that is deleted when it is closed. Temporary dynamic queues are not
recovered if the queue manager fails, so they can contain nonpersistent messages
only. See also permanent dynamic queue.
-
teraspace
- A one terabyte temporary
storage area that provides storage that is private to a process.
-
termination notification
- A pending
event that is activated when a CICS subsystem successfully connects to WebSphere MQ for z/OS.
-
this
- In object-oriented programming,
a keyword that identifies a special type of pointer that references the class
object in a member function.
-
thlqual
- See target library high-level qualifier.
-
thread
- The basic unit of program
execution. Several threads can run concurrently, performing different jobs.
-
TID
- See transaction
identifier.
-
time-independent messaging
- See asynchronous messaging. See also synchronous messaging.
-
TMF
- See Transaction
Manager Facility.
-
TMI
- See trigger
monitor interface.
-
TP
- See transaction
program.
-
trace
- A facility for recording WebSphere MQ activity. The destinations for trace entries can include
generalized trace facility (GTF) and the system management facility (SMF).
-
transaction
- A unit of processing
consisting of one or more application programs, affecting one or more objects,
that is initiated by a single request, often from a terminal.
-
transaction ID
- See transaction identifier.
-
transaction identifier ( TID transaction ID)
- A unique name that is assigned to a transaction and is used to
identify the actions associated with that transaction.
-
transaction manager
- A software unit
that coordinates the activities of resource managers by managing global transactions
and coordinating the decision to commit them or roll them back. WebSphere MQ is
a transaction manager.
-
Transaction Manager Facility (TMF)
- In MQSeries for Compaq NonStop Kernel, a subsystem to protect your business
transactions and the integrity of your databases. Often used synonymously
with NonStop Transaction Manager/MP.
-
transaction program (TP)
- A program
that processes transactions in an SNA network.
-
Transmission Control Protocol (TCP)
- A communications protocol used in the Internet and in any network that follows
the Internet Engineering Task Force (IETF) standards for internetwork protocol.
TCP provides a reliable host-to-host protocol between hosts in packet-switched
communications networks and in interconnected systems of such networks. It
uses the Internet Protocol (IP) as the underlying protocol. See also Internet Protocol.
-
Transmission Control Protocol/Internet Protocol
(TCP/IP)
- An industry-standard, nonproprietary set of communications
protocols that provide reliable end-to-end connections between applications
over interconnected networks of different types.
-
transmission program
- See message
channel agent.
-
transmission queue
- A local queue
on which prepared messages destined for a remote queue manager are temporarily
stored.
-
trigger event
- An event, such as a
message arriving on a queue, that causes a queue manager to create a trigger
message on an initiation queue.
-
triggering
- In Websphere MQ, a facility
that allows a queue manager to start an application automatically when predetermined
conditions on a queue are satisfied.
-
trigger message
- A message that contains
information about the program that a trigger monitor is to start.
-
trigger monitor
- A continuously running
application that serves one or more initiation queues. When a trigger message
arrives on an initiation queue, the trigger monitor retrieves the message.
It uses the information in the trigger message to start a process that serves
the queue on which a trigger event occurred.
-
trigger monitor interface (TMI)
- The WebSphere MQ interface to which customer- or vendor-written trigger monitor
programs must conform. A part of the WebSphere MQ Framework.
-
two-phase commit
- A protocol for the
coordination of changes to recoverable resources when more than one resource
manager is used by a single transaction. See also single-phase
commit.
-
type
- In object oriented programming,
a fundamental data type of computer architecture, including, for example,
character, string and integer.
U
-
UDP
- See User
Datagram Protocol.
-
unauthorized access
- Gaining access
to resources within a computer system without permission.
-
undelivered message queue
- See dead-letter queue.
-
undo/redo record
- A log record used
in recovery. The redo part of the record describes a change to be made to
a WebSphere MQ object. The undo part describes how to back out the change
if the work is not committed.
-
unit of recovery
- A recoverable sequence
of operations within a single resource manager, such as an instance of DB2 Universal Database for z/OS and OS/390. See also transaction.
-
unit of work
- A recoverable sequence
of operations performed by an application between two points of consistency.
A unit of work begins when a transaction starts or at a user-requested syncpoint.
It ends either at a user-requested syncpoint or at the end of a transaction.
-
user bag
- In the MQAI, a type of data
bag that is created by the user.
-
User Datagram Protocol (UDP)
- In the
Internet suite of protocols, a protocol that provides unreliable, connectionless
datagram service. It enables an application program on one machine or process
to send a datagram to an application program on another machine or process.
-
user item
- In the MQAI, a type of
data item that is created by the user.
-
user selector
- In the WebSphere MQ Administration
Interface (MQAI), the identifier that is placed with a data item into a data
bag to identify the data item. WebSphere MQ provides predefined user selectors
for WebSphere MQ objects.
-
utility
- In WebSphere MQ, a
supplied set of programs that provide the system operator or system administrator
with facilities in addition to those provided by the WebSphere MQ commands.
V
-
value
- The content of a data item.
This can be an integer, a string, or the handle of another bag.
-
virtual method
- In object-oriented
programming, a method that exhibits polymorphism.
W
-
WebSphere MQ
- A family of IBM licensed programs
that provides message queuing services.
-
WebSphere MQ Administration Interface (MQAI)
- A programming interface that performs administration tasks on
a WebSphere MQ queue manager through the use of data bags. Data bags allow
the user to handle properties (or parameters) of WebSphere MQ objects.
-
WebSphere MQ client
- Part of a WebSphere MQ product that can be installed on a system without installing
the full queue manager. The WebSphere MQ client accepts MQI calls from
applications and communicates with a queue manager on a server system. See
also client.
-
WebSphere MQ Internet pass-thru
- A WebSphere MQ base product extension supplied in SupportPac(TM) MS81.
It enables two queue managers to exchange messages, or a WebSphere MQ client
application to connect to a queue manager, over the Internet without requiring
a direct TCP/IP connection.
-
WebSphere MQ script commands (MQSC)
- Human readable commands, uniform across all platforms, that are used
to manipulate WebSphere MQ objects. See also programmable
command format.
-
WebSphere MQ server
- A queue manager
that provides queuing services to one or more clients. All the WebSphere MQ objects,
for example queues, exist only on the queue manager system, that is, on the
MQI server machine. A server can support normal local MQI applications as
well.
-
Windows NT(R) Challenge/Response
- The authentication protocol that is used on networks that include Windows NT systems and on standalone systems.
-
wiretapping
- The act of gaining access
to information that is flowing along a wire or any other type of conductor
used in communications. The objective of wiretapping is to gain unauthorized
access to information without being detected.
X
-
XCF
- See cross-system
coupling facility.
-
X/Open XA
- The X/Open Distributed
Transaction Processing XA interface. A proposed standard for distributed transaction
communication. The standard specifies a bidirectional interface between resource
managers that provide access to shared resources within transactions, and
between a transaction service that monitors and resolves transactions.
Y
Z