 






     Software
     Product
     Description

     ________________________________________________________________

     PRODUCT NAME:  DECmessageQ for VMS, Version 1.0     SPD 34.07.00

     DESCRIPTION

     DECmessageQ for VMS is the VMS Operating System implementation
     of a generic software message queuing bus that provides easy-to-
     use, efficient task-to-task communications among processes using
     DECmessageQ on VMS, ULTRIX, MS-DOS[R], and OS/2[R].

     A common call interface allows messages to be delivered via
     high-speed global sections for some intra-CPU applications,
     or via DECnet-VAX for inter-CPU applications. Applications can
     be designed so client applications can be redeployed easily
     anywhere within the DECmessageQ network configuration, whether
     in a standalone node, a Local Area Network (LAN), or a wide area
     network.

     The DECmessageQ communication implementation is designed for
     ease-of-use, expandability, and efficiency. Its features in-
     clude:

     o  High speed local message delivery using Global Sections

     o  Remote message delivery via DECnet

     o  Fully asynchronous and synchronous receipt of messages

     o  Message sizes up to 32,000 bytes

     o  Priority queuing of messages

     o  Message recovery using Message Recovery Services (MRS)

     o  Message broadcasting using Selective Broadcast Services (SBS)

                                  DIGITAL                  March 1991

                                                          AE-PF5FA-TE

 


     DECmessageQ for VMS, Version 1.0                    SPD 34.07.00



     o  Selective reception of messages according to certain fields
        within the DECmessageQ header and within the data portion of
        the message

     o  Shared input queues using Multi-Reader Queues (MRQ)

     o  Use of intra-CPU naming through high-speed global sections,
        and inter-CPU naming through VAX Distributed Name Service

     o  Message simulation facility for use in application testing

     o  Set of message delivery options

     o  Selectable tracing of Messages and calls to DECmessageQ

     o  A maximum of 999 queues per DECmessageQ Group

     o  A maximum of 32,000 DECmessageQ Groups

     o  Integration of VMS timers

     o  Support for languages adhering to the VAX Common Language
        standard

     o  Utilities for monitoring the network configuration and flow
        of messages

     o  Dynamic addition of message queues and CPUs to the communica-
        tion network

     o  Message interface for retrieving DECmessageQ configuration
        information on-line

     o  Portable call interface

     o  Connectivity to DECmessageQ implementations on VMS, ULTRIX,
        OS/2, and MS-DOS

     DECmessageQ for VMS can also be used as an integration tool
     to merge many external events with the message queuing bus.
     In addition to integrating messages from local processes and
     remote processes, DECmessageQ also provides facilities for the
     integration of other events such as:

                                     2

 


     DECmessageQ for VMS, Version 1.0                    SPD 34.07.00



        timer settings,
        simulated messages,
        LU6.2 conversations, or
        other external events such as special hardware I/O.

     DECmessageQ Queues

     DECmessageQ for VMS provides three types of queues. A queue is
     a memory storage location for DECmessageQ messages. Any process
     can insert a message into any queue. These queues are accessed
     directly by DECmessageQ procedures. These procedures are called
     by user-written applications. DECmessageQ queue types are:

     o  Primary Queue (PQ) - Each process that attaches to the mes-
        sage queuing bus is assigned a Primary Queue. This queue is
        used to receive messages from processes using DECmessageQ.

     o  Secondary Queue (SQ) - Any process may attach to one or more
        secondary queues. These queues can also be used to receive
        messages. The order in which queues are scanned for messages
        is defined by the DECmessageQ selection rules.

     o  Multi-Reader Queue (MRQ) - A Multi-Reader Queue is a single
        shared queue that can be shared by up to 40 simultaneous
        readers.

     Message Recovery Services (MRS)

     Message Recovery Services for the DECmessageQ Message Queuing
     Bus extend data recovery to the level of pending messages.
     Using Message Recovery Services, the sender is relieved of the
     responsibility of tracking the progress of a message through its
     next level of processing. This functionality can be used both at
     the client and server sides of the application.

     Message Recovery Services increase the robustness of DECmessageQ
     by providing applications with the ability to recover from
     message delivery failures due to:

     o  Application program abort

                                     3

 


     DECmessageQ for VMS, Version 1.0                    SPD 34.07.00



     o  Communication line failure

     o  System crash

     Some of the applications requirements addressed by MRS are:

     o  Sender wishes to insure delivery of messages when the re-
        ceiving process is available but does not wish to monitor the
        delivery.

     o  Sender wishes to know that a message is recoverable to avoid
        the cost of reconstructing it but does not care when it is
        finally delivered.

     o  Receiver wishes to maintain a journal of all messages re-
        ceived by it for audit trail or reprocessing.

     Message Recovery Services are primarily implemented by an MRS
     server, a non-privileged program attached to the DECmessageQ
     Message Bus. MRS actions are invoked by standard DECmessageQ
     send and receive message calls.

     MRS is oriented toward messages, not processes. That is, not
     all messages sent from or directed to a particular process need
     to be processed by MRS. This allows applications to selectively
     incur the additional processing imposed by MRS for just those
     messages that are not easily recovered. Message recovery charac-
     teristics are set by the sending process.

     Selective Broadcast Services (SBS)

     There are two important application requirements handled by this
     service. The first requirement is the ability to send a message
     to many targets without going through multiple application
     DECmessageQ send message requests. The second requirement is the
     ability to generate broadcast messages without the originator
     knowing the quantity or location of the target process(es).


                                     4

 


     DECmessageQ for VMS, Version 1.0                    SPD 34.07.00



     Selective Broadcast Services provide a conceptual broadcast
     stream of data. In this broadcast stream any process can insert
     a message. Any process can select messages from this broad-
     cast stream for delivery. Messages may be selected using a set
     of rules that provide relational comparisons against DECmes-
     sageQ header information or user's message data information. The
     Selective Broadcast Services operate in a single server environ-
     ment or between cooperating DECmessageQ servers. When the SBS is
     operating between nodes, it can operate using DECnet services or
     using direct Ethernet operations. In the direct Ethernet opera-
     tions, the SBS will optimize message traffic by using Ethernet's
     multi-casting capabilities.

     Delivery Options

     DECmessageQ for VMS provides the following set of delivery
     options:

     o  Datagram - A non-recoverable attempt is made to deliver a
        message. If the message cannot be delivered to a target then
        an error is logged.

     o  Wait for enqueue - The sending process will block until the
        message is written to the target queue. A return status will
        indicate if the message successfully enqueued to the queue.

     o  Blocking and non-blocking message Store-and-Forward - The
        sending process will send messages that are stored in a disk
        file locally, before they are sent over any communication
        link(s).

     o  Blocking and non-blocking message disk queuing - The sending
        process will send messages that will be delivered to the
        target's disk queue.

     DECmessageQ Scripts Facility

     The DECmessageQ scripts facility provides a general capability
     to perform message capture, simulation, and replay.

                                     5

 


     DECmessageQ for VMS, Version 1.0                    SPD 34.07.00



     o  Capture - DECmessageQ scripts can be used to capture messages
        that are sent or received from a process. These messages
        can be displayed on the output device or collected in a disk
        file. The messages are displayed in an ASCII file using the
        DECmessageQ scripts syntax.

     o  Simulation - A disk file containing DECmessageQ scripts com-
        mands can be used to simulate message traffic to a process.
        The commands use the DECmessageQ scripts syntax. The process
        will receive these messages after any DECmessageQ queue is
        scanned for receivable messages.

     o  Replay - A replay is the simulation of messages that were
        previously captured.

     DECmessageQ LU6.2 Services (License Option)

     DECmessageQ LU6.2 Services for VMS systems allows user pro-
     grams attached to a DECmessageQ Message Queuing Bus to request,
     accept, and conduct APPC (Advanced Program-to-Program Commu-
     nications) conversations with programs running under CICS/VS,
     IMS/VS, and other IBM[R] environments over SNA LU6.2 sessions.

     Note: See the DECnet/SNA APPC-LU6.2 Software Product Description
     (SPD 26.88.xx) for currently supported environments.

     DECmessageQ LU6.2 Services allows users unfamiliar with SNA
     communications to develop quickly and easily applications that
     operate with IBM-based APPC applications. Users are insulated
     from the details of both SNA and APPC. DECmessageQ provides ad-
     ditional insulation between the two environments by translating
     transaction program names known to DECmessageQ user programs to
     names known to the IBM system(s) and vice versa.

     DECmessageQ LU6.2 Services for VMS consists of:

     o  An LU6.2 Server image ("Port Server") that provides con-
        nection management facilities, isolating the end user from
        details of SNA-APPC communications

                                     6

 


     DECmessageQ for VMS, Version 1.0                    SPD 34.07.00



     o  A library of predefined DECmessageQ message structures for
        ease of program development

     o  Utilities for managing the LU6.2 Server

     o  Tools for developing user-written LU6.2 Servers

     DECmessageQ LU6.2 Services Limits

     DECmessageQ LU6.2 Services for VMS has the following limits:

     Maximum user message    31,982 bytes
     size:

     Maximum number of       256 per Port Server
     active LUs:

     Maximum number of       512 per DECmessageQ LU6.2 Server (user-
     remote                  written servers: unlimited)
     Transaction Pro-
     grams:

     DECmessageQ LU6.2 Services Utilities

     DECmessageQ LU6.2 Services for VMS includes a management utility
     that allows a suitably privileged user to start, stop, and
     configure DECmessageQ LU6.2 servers and observe their activity
     (through an event monitoring facility).

     Users can develop specialized LU6.2 servers by using the DECmes-
     sageQ LU6.2 Server tool kit. The tool kit consists of a DECmes-
     sageQ/VMS User Callback (a "user callback" is a special User
     Exit module) and 21 predefined DECmessageQ message structures.

     The LU6.2 Server tool kit gives the user a much finer degree of
     control over the APPC environment than the standard DECmessageQ
     LU6.2 Server. Functions supported via the tool kit are:

     o  DEFINE_LU

     o  DEFINE_TP

                                     7

 


     DECmessageQ for VMS, Version 1.0                    SPD 34.07.00



     o  DELETE_LU

     o  ALLOCATE_CONVERSATION

     o  DEALLOCATE_CONVERSATION

     o  REQUEST_CONFIRMATION

     o  ISSUE_CONFIRMATION

     o  ISSUE_ERROR

     o  REQUEST_TO_SEND

     o  SEND

     o  RECEIVE

     HARDWARE REQUIREMENTS

     VAX, MicroVAX, VAXstation, or VAXserver configuration as speci-
     fied in the System Support Addendum (SSA 34.07.00-x).

     SOFTWARE REQUIREMENTS

     VMS Operating System
     DECnet/SNA APPC LU6.2 Programming Interface
        (for LU6.2 Services option only)

     OPTIONAL SOFTWARE

     DECnet-VAX
     VAX Distributed Name Service
     DECmessageQ for ULTRIX
     DECmessageQ for MS-DOS
     DECmessageQ for OS/2



                                     8

 


     DECmessageQ for VMS, Version 1.0                    SPD 34.07.00



     ORDERING INFORMATION

     Development Option

     The DECmessageQ for VMS/Development Option includes the base
     message queuing software, language compiler binding libraries,
     and configuration definition utilities.

     Run-Time Only Option

     The Run-Time Only Option provides all the facilities of the de-
     velopment version of DECmessageQ for VMS except the language
     compiler binding libraries and the configuration definition
     utilities. The purpose of the Run-Time Only version is to sup-
     port the execution of previously developed applications on a
     target machine. Program development is not supported under the
     Run-Time Only Option.

     LU6.2 Services Option

     The DECmessageQ for VMS/LU6.2 Services option supports conversa-
     tions with programs running under CICS/VS, IMS/VS, and other IBM
     environments over SNA LU6.2 sessions.

     Software Licenses:

     DECmessageQ for VMS/Development: QL-GKPA9-J*
     DECmessageQ for VMS/Run-Time Only: QL-GHVA9-J*
     DECmessageQ for VMS/LU6.2 Services:
        QL-GKQA9-J*

     Software Media:

     DECmessageQ for VMS/Development: QA-GKPAA-H*
     DECmessageQ for VMS/Run-Time Only:
        QA-GKPAA-H*
     DECmessageQ for VMS/LU6.2 Services:
        QA-GKPAA-H*

     Software Documentation:

                                     9

 


     DECmessageQ for VMS, Version 1.0                    SPD 34.07.00



     DECmessageQ for VMS/Development: QA-GKPAA-GZ
     DECmessageQ for VMS/Run-Time Only:
        QA-GKPAA-GZ
     DECmessageQ for VMS/LU6.2 Services:
        QA-GKPAA-GZ

     Software Product Services:

     DECmessageQ for VMS/Development: QT-GKPA*-**
     DECmessageQ for VMS/Run-Time Only: QT-GHVA*-**
     DECmessageQ for VMS/LU6.2 Services: QT-GKQA*-**

     *  Denotes variant fields. For additional information on avail-
        able licenses, services, and media, refer to the appropriate
        price book.

     SOFTWARE LICENSING

     This software is furnished under the licensing provisions of
     Digital Equipment Corporation's Standard Terms and Conditions.
     For more information about Digital's licensing terms and poli-
     cies, contact your local Digital office.

     LICENSE MANAGEMENT FACILITY SUPPORT

     This layered product supports the VMS License Management Facil-
     ity.

     License units for this product are allocated on a CPU-capacity
     basis.

     For more information on the License Management Facility, refer
     to the VMS Operating System Software Product Description (SPD
     25.01.xx) or the License Management Facility manual of the VMS
     Operating System documentation set.

     For more information about Digital's licensing terms and poli-
     cies, contact your local Digital office.

                                    10

 


     DECmessageQ for VMS, Version 1.0                    SPD 34.07.00



     SOFTWARE PRODUCT SERVICES

     A variety of service options are available from Digital. For
     more information, contact your local Digital office.

     SOFTWARE WARRANTY

     Warranty for this software product is provided by Digital with
     the purchase of a license for the product as defined in the
     Software Warranty Addendum of this SPD.

     [R]  IBM and OS/2 are registered trademarks of International
          Business Machines Corporation.

     [R]  MS-DOS is a registered trademark of Microsoft Corporation.

     [TM] The DIGITAL Logo, CI, DECwindows, DECnet, DECnet-VAX,
          MicroVAX, ULTRIX, VAX, VAXcluster, VAXft, VAXserver,
          VAXstation, and VMS are trademarks of Digital Equipment
          Corporation.



















                                    11
