Release 10.1A: OpenEdge Getting Started:
Application and Integration Services

Application and integration services in OpenEdge

Service and SOA support in OpenEdge targets different levels of granularity and infrastructure, with varying capacities to support application and integration services.

Application service support

The OpenEdge Application Server and its components provide the core technologies for developing application services in OpenEdge. Some components of the OpenEdge Application Server (for example, Progress® 4GL Web services) also support the development of integration services.

The two core technologies that form the basis of application service support in OpenEdge include the OpenEdge AppServer™ and WebSpeed®, both of which support the development of application services using the Progress 4GL and the WebSpeed variant, SpeedScript®. The AppServer supports Progress 4GL sessions that run 4GL procedures (remote procedures) that are invoked from requests sent by client programs running in separate application sessions that are often running on separate machines. In response, the AppServer returns the results of each remote procedure execution as output parameters or return values as though executed in the same session as the client. As such, the remote procedures available on a single AppServer platform combine to create an application service that is available to clients designed to access it.

WebSpeed supports SpeedScript sessions that run SpeedScript procedures (called Web objects) that are invoked from HTTP Get and Post requests sent over the Internet from a Web browser (HTTP client) and passed by a Web server to the appropriate WebSpeed session. In response, WebSpeed returns the results of each Web object execution as an HTML page that can be interpreted and displayed in the Web browser. As such, the Web objects available on a single WebSpeed platform combine to create an application service that is available to any HTTP client with access to the Web site that handles the WebSpeed requests. Thus, WebSpeed is specialized to provide application services to Web browser clients.

Additional components, such as Web services tools and the Open Client Toolkit, enhance the accessibility and availability of application services provided by these core technologies. For more information on Web services tools, see the "Integration service support" section. The Open Client Toolkit supports the Web services tools and also supports the development of non-Progress 4GL clients that can directly access AppServer application services. For more information on Open Client support, see Chapter 4, " OpenEdge Open Clients."

For more information on how the OpenEdge Application Server supports application service development, deployment, and management, see Chapter 2, " OpenEdge Application Server Architecture."

Integration service support

The OpenEdge Adapter for SonicMQ®, Web services tools, and the OpenEdge Adapter for Sonic ESB® provide the core technologies for developing integration services in OpenEdge. The SonicMQ Adapter allows a Progress 4GL (or SpeedScript) application to become a client of the Java™ Message Service (JMS) backbone provided by SonicMQ (product available from Sonic Software Corporation). As a JMS client, the 4GL application can exchange messages in a variety of formats with other OpenEdge or non-OpenEdge applications that also use SonicMQ as their JMS backbone. For more information on the OpenEdge Adapter for SonicMQ, see Chapter 7, " OpenEdge Messaging and ESB." For more information on SonicMQ, see the product documentation available from Sonic Software Corporation.

The Web services tools support the development and deployment of Web services based on existing AppServer application services that can be accessed by any Web service client. Relying largely on the Open Client Toolkit for development and the Web Services Adapter (WSA) for deployment, Progress 4GL Web services thus provide a means to integrate AppServer application services with any application domain that supports access to Web services. The Web services tools also include support for the ability of Progress 4GL applications to access industry Web services in a manner very similar to accessing AppServer application services. Thus, Progress 4GL applications can integrate application services developed on most any other platform, such as Java or Microsoft .NET. For more information on OpenEdge support for Web services, see Chapter 6, " Web Services in OpenEdge—Architecture and Tools."

The OpenEdge Adapter for Sonic ESB allows a Web service developed in OpenEdge (Progress 4GL Web service) to be deployed as an OpenEdge service in the Sonic ESB environment, where it can then be integrated with other services and made available to a wide variety of application types and platforms using the integration technology provided by the Sonic ESB. For more information on the OpenEdge Adapter for Sonic ESB, see Chapter 7, " OpenEdge Messaging and ESB." For more information on Sonic ESB, see the product documentation available from Sonic Software Corporation.

Services foundations in OpenEdge

The whole basis for services and SOA support in OpenEdge is in its support for distributed application computing. The following sections describe this support and compare it to the client/server computing models that have preceded it.