Glossary

 

access control list (ACL)

A list that defines the kinds of access to be granted or denied to users of an object. Access control lists can be created or objects such as files and devices.

acknowledgment (ACK)

A status message that indicates the completion of an operation.

address

See queue address.

application

A program or collection of programs designed to perform a function or business task.

application programming interface (API)

An interface used by application programs to call services external to the program. The API supports the exchange of information in a multivendor environment.

application protocols

An agreed set of rules that govern the management of connections between partner programs. See also duplex connection and simplex connection.

asynchronous

Pertaining to a style of message queuing whereby messages can be sent or received at any time without waiting for the receiver program to receive, process, or respond to a specific event. Contrast with synchronous.

asynchronous system trap (AST)

An software-simulated interrupt to a user-defined service routine. ASTs enable a user process to be notified asynchronously of the occurrence of a specific event. If a user has defined an AST routine for an event, the system interrupts the process and executes the AST routine when that event occurs. When the AST routine exits, the system resumes execution of the process at the point where it was interrupted.

attach

To make a process known to the BEA MessageQ message queuing bus and allow it to receive messages at a particular queue address.

attachment point

A particular queue location on the BEA MessageQ message queuing bus that allows communication between processes without requiring a formal connection sequence.

blocking

Pertaining to a synchronous style of message delivery where the program is forced to wait for an action to complete. Contrast with nonblocking.

broadcast distribution

The action of delivering a message to all processes interested in a particular broadcast stream.

broadcasting

A style of communicating that uses one message sender program and multiple message receiver programs. This capability is also called "publish and subscribe."

broadcast stream

A data message pipeline that has a single entry point and multiple exit points. Messages sent to the broadcast stream are simultaneously distributed to all registered queues. See also private broadcast stream and universal broadcast stream.

buffer

An internal memory area used for temporary storage of data records during input or output operations.

buffer pool

A common memory area that stores message buffers for a message queuing group. A buffer pool consists of fixed-size memory structures that can hold one message each.

bus ID

A reference value that distinguishes one BEA MessageQ message queuing bus from another.

class

A 16-bit piece of data that describes a grouping or category of message types. Also called message class. See also type.

client

A computing system entity that uses the services of other system entities called servers. See also server.

client/server model

A hardware or software system design used in developing distributed applications. In the client/server model, a server system provides common database access, performs computations, and assumes system management tasks for its clients.

COM Server

A BEA MessageQ for OpenVMS server process that passes cross-group messages to other BEA MessageQ message queuing groups. A COM Server creates the BEA MessageQ message queuing bus environment and must be activated before message queuing can occur.

configuration editor

A Windows editor used for defining and managing BEA MessageQ buses, groups, and related information.

configuration file

A text file comprised of information line items used to configure BEA MessageQ software. This file is also called the group initialization file. The configuration data for message queuing groups is standard for all platforms.

confirmation

See message confirmation.

connectionless

Pertaining to not having a logical link. A connection does not have to be established with a partner process in order to pass information between them.

connection-oriented

Pertaining to a communication method where two partners must establish a connection before they can exchange messages.

correlation ID

A user-defined value associated with and identifying a specific message. Receiving applications can retrieve the correlation ID and tag any responses with the same value. This aids in matching responses with requests.

cross-group

Pertaining to messages that pass between BEA MessageQ message queuing groups. A cross-group message is targeted to a message queuing group outside of the local group. Cross-group connections enable applications to share information across different systems connected to the same message queuing bus.

datagram

A "best effort" style of message delivery in which a nonrecoverable attempt is made to deliver a message. If the message cannot be delivered to a target, then an error is logged.

dead letter journal (DLJ)

A file that provides nonvolatile disk storage for messages that cannot be stored for automatic recovery. Applications use the DLJ file to resend undelivered messages. Also called DLJ file.

dead letter queue (DLQ)

The permanent message queue that provides memory-based storage of all recoverable messages that could not be stored for automatic delivery. Also called DLQ file.

delivery interest point

A component of the delivery mode that indicates the step in the message recovery data flow at which the sender program is notified.

delivery mode

A selection of options that specify how the sender program receives notification of recoverable message delivery and the point in the message flow at which the notification is sent. See also message delivery.

destination queue file (DQF)

A message recovery journal that provides nonvolatile storage on a remote system for automatic recovery and delivery of messages. Also called DQF file.

distributed application

An application that divides the user interface, processing, or data among one or more units that execute on a single central processing unit (CPU) or multiple nodes in a network.

distributed computing

An application design methodology that places data entry and application processing close to departmental and functional end users. These users are most familiar with the input requirements and need the processed output to support their business objectives.

Distributed Name Services (DNS)

A heavyweight namespace that BEA MessageQ can use to store global names. Using DNS on OpenVMS systems enables BEA MessageQ to locate the queue address for a queue defined by any group on the message queuing bus. See also naming.

distribution

A stage in broadcast services where the SBS Server delivers a message to receiver programs.

distribution queue

A queue address that is specified in a broadcast or availability services registration message. The distribution queue is the final destination of a broadcast or availability notification message.

DLJ file

See dead letter journal.

DLQ file

See dead letter queue.

DQF file

See destination queue file.

duplex connection

An application protocol where the initiating partner is the sender program and the accepting partner is the receiver program, until the sender program requests a direction change and becomes the new receiver program. The accepting partner then becomes the sender program and remains the sender program until requesting a direction change. Contrast with simplex connection.

event

A network- or system-specific occurrence, such as timer expiration, for which the logging component maintains a record.

explicit confirmation

A type of message confirmation that requires the receiver program to delete the message from the recovery journal using a message sequence number. The message is not deleted until the receiver program has finished processing the information in it.

facility

A collection of one or more computer programs that implement a set of related functions or services. The implementation of a facility can consist of either a process or a procedure.

failover

The process of a reconfiguration after a hard fault or for planned maintenance.

The ability of a system or component to reconfigure itself.

Field Manipulation Language (FML)

Field Manipulation Language (FML) is a set of C language functions for defining and manipulating storage structures called fielded buffers, that contain attribute-value pairs in fields. The attribute is the field's identifier, and the associated value represents the field's data content.

FML

See Field Manipulation Language.

full duplex

Pertaining to a communications method in which data can be transmitted and received at the same time.

global data structure

A data structure that can be shared by multiple processes.

global sections

An OpenVMS shared memory segment potentially available to all processes in the system. Access is protected by standard access control mechanisms.

group

See message queuing group.

group ID

The internal number of the BEA MessageQ message queuing group. The group ID is part of the queue address. Each group ID must be unique within the message queuing bus.

group name

The symbolic name associated with the BEA MessageQ group ID.

half-duplex

Pertaining to a communication method where one partner is sending data when the other partner is receiving data. See also duplex connection.

heterogeneous computing environment

An environment in which applications run on computer systems from different vendors employing various operating system and networking software.

heterogeneous messaging

The use of different communications methods to transfer messages.

heterogeneous operating systems

A configuration of a variety of computers and operating systems connected by networking hardware and software.

implicit confirmation

A type of message confirmation on BEA MessageQ for UNIX and Windows NT systems that automatically deletes a recoverable message from a journal file. The receiver program does not need to respond to the receipt of the message.

inbound conversation allocation

The allocation of conversations that are initiated by an OpenVMS transaction program.

initiator-only deallocation

A method of duplex connection termination where the initiating partner is the only one who can terminate the connection normally. Contrast with open deallocation.

interprocess communication

Two-way communication between active independent processes.

journaled guaranteed delivery

A method used by applications to guarantee BEA MessageQ message delivery in which the sending process sends a message that is delivered to the target disk queue.

journal file

A disk file that records all received and confirmed messages.

journaling

Writing to a auxiliary message recovery journal file.

journal replay

A method for resending messages stored in the DLJ or PCJ files.

link driver

A process that establishes a communications link between message queuing groups. Using the queuing engine, each link driver sends outbound messages and delivers inbound messages.

Linked List Sections

A set of global sections that is used to store the BEA MessageQ message buffers for a message queuing group. See also buffer pool.

message

A data item that is transmitted over a communications medium. A message contains a message header and data portion. The message header is comprised of attributes, which are defined by the application program, and context, which is added by the messaging tool.

message-based services

Predefined request, notification, and response messages exchanged between the application and BEA MessageQ server process.

message capture

A part of the Script Facility that provides a mechanism for viewing messages that are sent or received by an application.

message confirmation

An action taken by the receiver program, which indicates to the message queuing system that the processing of a recoverable message has completed. A message confirmation terminates the message system's responsibility for the recoverable message.

Message Control Section (MCS)

A global section that stores information about message queues and other global information, such as send and receive counters.

message delivery

The processing steps performed by the message queuing system when moving the message from a sender program to the receiver program's message queue.

message queue

An attachment point on the BEA MessageQ message queuing bus where pending messages are stored. A message queue is identified by a queue number and can be primary, secondary, or multireader.

message queuing

Interprocess communication and information exchange between two or more cooperating processes accomplished by directing messages to a memory- or disk-based queue as an intermediate storage point.

message queuing bus

A transparent communication mechanism that uses a simple logical bus topology. A message queuing bus provides a standard set of program-callable subroutines that allow message transfer between programs and message queues. See also MessageQ message queuing bus.

message queuing group

A set of logical addresses on the BEA MessageQ message queuing bus, all sharing a set of common BEA MessageQ resources. Each message queuing group resides on a single system. However, multiple groups can reside on the same system. The interconnections between groups define the extent of a message queuing bus.

Message Recovery Services (MRS)

A set of BEA MessageQ services that manage the automatic redelivery of critical messages.

Multipoint Outbound Target (MOT)

An entry point to a broadcast stream. A range of queue addresses is reserved to define a set of unique broadcast streams.

multireader queue (MRQ)

An optional queue type on the BEA MessageQ message queuing bus that stores messages that can be read by several simultaneous readers. Each reader, in turn, receives the next message in first-in/first-out (FIFO) order from the queue. A multireader queue can be permanent or permanently active. See also queue type.

naming

Pertaining to the use of a symbolic entity in place of an actual value. BEA MessageQ uses character strings for names, which, when translated, reveal queue addresses.

network

A collection of interconnected individual computer systems.

node

An individual computer system in a network that can communicate with other computer systems in the network.

nonblocking

Pertaining to an asynchronous style of message delivery where the program does not have to wait for an action to complete. The nonblocking style generally involves receiving an acknowledgment message when the action is complete. Contrast with blocking.

notification

A type of message-based service that supplies up-to-date information on events as they occur.

open deallocation

A method of duplex connection termination where the current sender can terminate the connection normally, regardless of which partner initiated the connection. Contrast with initiator-only deallocation.

operand

Data in the message header or message data structure that will be compared.

outbound conversation allocation

The allocation of conversations that are initiated by a CICS transaction program.

PAMS

Process Activation and Message Support. PAMS is the original name for the BEA MessageQ message queuing system. The BEA MessageQ API preserves the original product acronym in the name of each callable service to protect customer investment in application development.

PCJ file

See postconfirmation journal file.

pending

Pertaining to a message that is currently in a queue.

permanent outbound target

A type of outbound target that supports a method of message delivery where BEA MessageQ clients can request that outbound traffic be delivered to a predetermined BEA MessageQ queue. The queue must be a permanent queue in the designated group.

permanent queue

A message queue that is always at the same address on the BEA MessageQ message queuing bus. It exists regardless of whether a process is attached to it. A permanent queue retains its name and address after the process detaches, but loses any pending messages. See also permanently active queue. Contrast with temporary queue.

permanently active queue

A message queue that can receive messages without an application attachment. It retains its name and messages after the process detaches from BEA MessageQ. See also permanent queue.

platform

The combination of hardware, operating systems, and windowing systems that supports an application.

port server

A class of BEA MessageQ application that provides a connection to the BEA MessageQ message queuing bus for client applications executing on platforms that do not have a BEA MessageQ implementation.

postconfirmation journal file (PCJ)

A disk file that holds confirmed recoverable messages that can be retrieved for audit trailing. Also called PCJ file.

primary queue

The one required queue used when a process attaches to the BEA MessageQ message queuing bus. There can be only one primary queue for each process. It is used as the default return address on all messages sent by that process. A primary queue can be permanent, permanently active, or temporary. See also queue type.

private broadcast stream

A MOT address range indicating that messages are restricted to distribution by one SBS Server, which restricts distribution to queues that have registered with that SBS Server. See also broadcast stream.

process

The basic entity scheduled by the system software, a process provides the context in which an image executes.

queue

See message queue.

queue address

A longword value that uniquely identifies the attachment point on the BEA MessageQ message queuing bus. An address includes a group ID and a queue number.

queue attribute

A specific characteristic of a queue that determines the features of the queue. Some examples of queue attributes are: permanent or temporary, recoverable or volatile, FIFO or non-FIFO capability, and so on.

queue number

A number that represents a unique location of a permanent or temporary queue address within a BEA MessageQ message queuing group. There must be at least one queue number for every process using the BEA MessageQ message queuing bus.

queue type

A description of a message queue as being primary, secondary, or multireader.

queuing engine

A process that handles all message traffic between message queuing groups. One queuing engine is created for each group. The queuing engine creates the global sections of memory for message queues within the group.

quota

The total amount of a system resource, such as disk space, that a job is allowed to use in an accounting period.

receive message quota

The application-defined limitation (in bytes) on pending messages in a queue.

receiver program

The application program in a connection that is accepting messages from the sender program.

recoverable message

A message that is temporarily stored on a disk file and is guaranteed delivery if an application, system, or network fails.

registration

A stage in broadcast services where an application program subscribes to a broadcast stream by sending a registration message to the SBS Server.

Registry

A database in the Windows NT operating system that stores system and optional software configuration information.

reliable transmission

Pertaining to messages that are guaranteed to be delivered to a target queue. Contrast with recoverable message.

request

A type of message-based service that obtains information or registers to receive ongoing notifications.

response

A type of message-based service that provides information to fulfill requests or acknowledge registration and deregistration requests.

return-to-sender

A method of BEA MessageQ message delivery in which a nonrecoverable attempt is made to deliver a message. If the message cannot be delivered, it is returned to the sending process marked with a special return status.

SAF file

See store and forward.

Script facility

A productivity tool that speeds application testing by providing message simulation, capture, and replay abilities.

script file

A file with special syntax defining message information.

secondary queue

An optional private queue type used in conjunction with a primary queue. It provides a secondary address for messages. A secondary queue can be permanent, permanently active, or temporary. See also queue type.

Selective Broadcast Services (SBS)

BEA MessageQ services that enable an application to send a message to many receiving applications with a single send operation.

semaphore

In BEA MessageQ software, a common data structure used to serialize access to shared data structures.

sender notification

A component of the delivery mode that indicates how the sender program wants to receive information about the delivery of the message.

sender program

The application program in a connection that is sending messages to the receiver program.

sequence number

The message sequence number is generated by the BEA MessageQ message recovery system for each recoverable message. This value is passed to the receiver program in the PAMS status buffer (PSB) of the pams_get_msg function when it reads each recoverable message.

server

A software module designed to perform a specific function for many users. See also client and client/server model.

sessionless

Pertaining to the absence of protocols required to manage communications between processes.

shared memory segment

A portion of memory that can be accessed by two or more processes.

simplex connection

An application protocol where the initiating partner is always the sender program and the accepting partner is always the receiver program. The receiver program can signal an error, but cannot send. Contrast with duplex connection.

source queue

A queue address of the program that sent the message.

stateless

Pertaining to the absence of protocols to identify the stages within a message transmission.

store and forward (SAF)

A message recovery journal that provides nonvolatile storage on the sender's system for automatic recovery and delivery of messages. Also called SAF file.

submission

A stage in broadcast services where an application program inserts a message on a broadcast stream.

synchronous

Pertaining to a message queuing system where the sender program must wait for a specific event or reply. Contrast with asynchronous.

target

A generic term for the client application with which another client application wants to establish a connection.

target queue

The queue address of the receiver program of the message.

TCP/IP

Transport Control Protocol/Internet Protocol. TCP/IP is a set of protocols that governs the transport of information between computers and networks of dissimilar types. Both Internet and UNIX based systems use TCP/IP protocols.

temporary queue

A queue that exists only for the duration of the process attachment to the BEA MessageQ message queuing bus. The assignment of the queue is not permanently defined. A temporary queue loses all messages in the queue when the process detaches from the queue. Contrast with permanent queue.

transparent

Relating to IBM systems, which use EBCDIC data encoding format. BEA MessageQ clients expect data in ASCII format. For a target defined as transparent, the LU6.2 Port Server does not provide data encoding format translation. Contrast with nontransparent.

type

A 16-bit piece of data BEA MessageQ uses to identify a kind of message from all other messages in the application. See also class.

undeliverable message action (UMA)

The action that occurs when the BEA MessageQ message queuing bus is unable to store a message. The UMA specifies the action to be taken with the recoverable message if it cannot be stored for guaranteed delivery by the message recovery system.

universal broadcast stream

A MOT address range indicating that messages can be distributed by all SBS Servers. Distribution is across the entire message queuing bus wherever SBS software is running. See also broadcast stream.

user process

A user's program image.

utility

A program that provides a set of related general-purpose functions, such as a program development utility (an editor, a linker).

wait for dequeue

A method of BEA MessageQ message delivery in which the sending process is blocked until the message is read from the target queue by the receiver program.

wait for enqueue

A method of BEA MessageQ message delivery in which the sender program process is blocked until the message is written to the target queue. A return status indicates if the message is successfully written to the queue. This delivery method guarantees message delivery when message recovery services are not available on the target platform.