Chapter 1 . Introducing BEA Connect TPS

Connect TPS is a gateway connectivity feature that makes it possible for application programs on BEA TUXEDO systems to perform non-transactional tasks with application programs in other OLTP systems that support Connect TPS gateways. These include:

• CICS on IBM MVS systems

• IMS/TM on IBM MVS systems

• IMS/DC on IBM MVS systems

Connect TPS is designed to provide transparent access to services that reside outside a BEA TUXEDO region. In addition, Connect TPS can provide remote application programs with access to local services if this is supported by the release of Connect TPS software installed on the remote system.

To establish connections with remote systems, an administrator performs the following tasks:

• Configures Connect TPS as an ordinary BEA TUXEDO server group by updating the BEA TUXEDO configuration

• Identifies remote systems, available services, and input and output data formats associated with available services by updating the Connect TPS configuration

Connect TPS and the BEA TUXEDO Architecture

A BEA TUXEDO region consists of client and server programs that operate across a network of BEA TUXEDO systems or compatible systems. Any client program can request services that are offered by any server program running on any computer in the region. Further, by way of a directory that maps services to servers, the location of server programs is kept transparent.

As Figure 1-1 shows, Connect TPS extends this transparent access by sending requests to and receiving requests from remote regions and systems through TCP/IP network software

Figure 1-1 Routing Service Calls through BEA Connect TPS

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As Figure 1-1 suggests, inside a single region, Connect TPS fits between the BEA TUXEDO software and TCP/IP.

• When local client programs send requests to remote systems, Connect TPS transforms those requests into messages formatted appropriately for transmission to the remote system. Also, when remote systems respond, Connect TPS transforms these responses into replies that local client programs can process.

• When remote client programs send request messages, Connect TPS transforms those messages into requests that local service routines can process. Also, when local service routines send replies, Connect TPS transforms those replies into messages that remote services can process.

Connect TPS is implemented as an ordinary BEA TUXEDO server group. It accepts standard BEA TUXEDO service requests and returns standard replies.

One Connect TPS server group acts as a gateway to multiple communications targets, also referred to as gateways. Each communications target, or gateway, is a unique network endpoint.

The remote gateways must also support Connect TPS. Connect TPS servers associated with the local gateway communicate with remote Connect TPS gateways to non-BEA TUXEDO TP monitors, such as BEA Connect TCP for CICS and BEA Connect TCP for IMS.

Although remote systems are identified in the Connect TPS configuration, they remain unknown to BEA TUXEDO software. For example, remote systems that are accessible through Connect TPS are not identified in the *MACHINES section of the UBBCONFIG file.

Connect TPS maintains its own control information in shared memory, in much the same way that BEA TUXEDO software itself maintains the Bulletin Board. Although Connect TPS accesses the BEA TUXEDO Bulletin Board, BEA TUXEDO does not access Connect TPS control information.

Connect TPS Components

Connect TPS includes several components. Each component is briefly defined in the following subsections.

The Liaison (TPSL)

The Connect TPS Liaison is the supervisory process for the Connect TPS server group. Its role is analogous to the role that is played by the bulletin board liaison (BBL) in the BEA TUXEDO environment.

The Connect TPS Liaison is registered in the local BEA TUXEDO bulletin board as a BEA TUXEDO server. When the Liaison is invoked, it forks off Handlers as necessary to process service requests received from remote systems.

After it starts Handlers, the Liaison acts as an administrative process, collecting statistics from each Requester and Handler through shared memory. The Liaison periodically polls Handlers to ensure that they are still alive. If a Handler dies, the Liaison logs a message on the local system. When the Liaison shuts down, it instructs all Handlers to shut down.

A Connect TPS server group must have one Liaison.

Note: Dead Connect TPS Requesters and Liaisons are restarted or cleaned up by the local BEA TUXEDO BBL process.

Requesters (TPSR)

Requesters are registered in the local Bulletin Board as BEA TUXEDO servers. They call out to connect to remote regions or systems. A Connect TPS server group can have zero or more Requesters.

Handlers (TPSH)

Handlers are registered in the local Bulletin Board as BEA TUXEDO client programs. They handle all network traffic from remote gateways that have connected to the Handler processes.

How Connect TPS Affects BEA TUXEDO Application Programs

Connect TPS preserves the high degree of location transparency that BEA TUXEDO software provides. In fact, in virtually all cases, programmers do not need to know that particular services are provided by remote systems.

Connect TPS supports the main BEA TUXEDO communication paradigm - request/reply communications (either synchronous or asynchronous).

All BEA TUXEDO buffer types can be employed for data exchange. These include:

• X/Open standard XATMI buffer types

  • X_OCTET

  • X_C_TYPE

  • X_COMMON

• BEA TUXEDO ATMI buffers

  • CARRAY

  • STRING

  • FML

  • VIEW

Each of the three X/Open buffer types is equivalent to a BEA TUXEDO ATMI buffer type. The following information provides these equivalencies.

• X_OCTET is equivalent to CARRAY

• X_C_TYPE is equivalent to VIEW

• X_COMMON is equivalent to VIEW, but represents only the subset of field types that are common to both the C and COBOL languages

VIEW Definitions

In some circumstances, you must convert typed buffers to formats that are acceptable to target systems. The standard BEA TUXEDO system VIEW definition mechanism is employed for this purpose.

VIEW definitions make it possible to map input data and output data between different programming environments (such as C and COBOL). They also enable Connect TPS to convert data representations automatically between different systems

VIEW definitions can be created by programmers or system administrators. See Chapter 3, "Installing and Getting Ready to Configure BEA Connect TPS," for details. For more detailed information about programming considerations, see Chapter 2, "Understanding How BEA Connect TPS Works".

FML Buffer Support

When communicating with systems or regions that do not support FML buffers directly, the Connect TPS gateway can convert FML buffers to or from user-defined record layouts in a manner transparent to the FML application. Thus, once a VIEW definition that describes the remote application's record layout is created, it can be used to convert the record to or from an FML buffer. The TPSINIT file (Connect TPS configuration file) contains VIEW specifications as part of the service description.

Through this conversion between ATMI buffers and record structures, Connect TPS supports sending fielded buffers containing FML data between regions. The Connect TPS software converts the data from FML buffers to user-defined records using the VIEW definitions and field descriptions at the originating region.

How Connect TPS Affects BEA TUXEDO Administration

Connect TPS administration tools and features are thoroughly integrated with BEA TUXEDO administration tools and features. Here are some specific examples:

• System administrators define Connect TPS in the BEA TUXEDO configuration as a regular BEA TUXEDO server group.

• The Connect TPS configuration file (TPSINIT) specifies how local BEA TUXEDO service names are mapped to remote service names. Also, the TPSINIT file identifies VIEW definitions that Connect TPS uses to convert and translate input and output data. System administrators specify the Connect TPS TPSINIT file in the BEA TUXEDO configuration. The file is read when Connect TPS servers are started.

• At run time, system administrators use BEA TUXEDO tmadmin subcommands to manage Connect TPS and related processes.

For more detailed information about configuring Connect TPS, see Chapter 3, "Installing and Getting Ready to Configure BEA Connect TPS," and Chapter 4, "Configuring BEA Connect TPS". For more detailed information about administering Connect TPS, see Chapter 6, "Administering BEA Connect TPS".