WebSphere V3.5 and V4.0 / Domino Integration: Connection Methods

There are different methods that can be used to enable interaction between WebSphere and Domino. The most common and useful methods are discussed here. The first method of WebSphere/Domino integration, using HTTP (or secure HTTPS), is unique for use with WebSphere Version 4.0. The last four methods are unique for use with WebSphere Version 3.5, and are fundamentally different from one another. Some of the differences include:

• When using OSE Remote, the interface is configured, not programmed. In this configuration, we continue to use the HTTP task in Domino, but WebSphere is accessed on a separate server.
• When using a servlet redirector, we actually have WebSphere running on the Domino server. The only task that it does is to redirect any WebSphere requests to the real WebSphere server.
• When using the IIOP, the interface must be programmed, and makes use of the Web server running on the WebSphere server.
• When using SOAP, the control of WebSphere must be programmed to output the XML according to the SOAP Data Type Definition (DTD) so that WebSphere can understand the request. The XML could be transmitted via a number of methods, from sockets/pipes to HTTP. We have illustrated the XML being sent to WebSphere via HTTP because it looks like that will become the most popular transmission method as SOAP gains popularity.

Your decision about which communication option to choose should be based on a number of factors, such as security, throughput, and corporate strategy.

Select the connection method that best meets the needs of your e-business solution:

HTTP or HTTPS

The HTTP (or secure HTTPS) connection method between Domino and WebSphere is supported only in WebSphere V4.0.

OSE Remote

The WebSphere Application Server uses OSE transport to communicate between the Web server plug-in and the servlet engine. When running both the HTTP server and WebSphere on the same machine, OSE is run over local pipes. If the HTTP server and WebSphere are running on different machines, we can use OSE Remote.

OSE Remote allows the HTTP server to run on a distinct machine and send requests to application servers running on remote machines. OSE supports clustering and workload management on application servers. This means that the HTTP server can send requests that require intensive processing to different jobs or machines, freeing up the HTTP server machine to process more requests. This provides both vertical and horizontal scaling of the WebSphere environment.

In WebSphere Application Server V4.0, OSE Remote has been replaced by an HTTP transport using the same port assignments. This allows you to encrypt the transport using HTTPS. OSE Remote does not support data encryption.

Servlet Redirector

A servlet redirector is a special case of an application server that runs on the same computer as the HTTP server and its plug-in file. It receives requests from the plug-in by using (local) OSE and forwards them to a remote servlet engine session bean. Each WebSphere server has a stateless session bean that listens for requests and forwards them to the servlet engine in the WebSphere application server.

Servlet redirector is not supported in WebSphere Application Server V4.0. It is included with WebSphere v3.5 because it allows encryption of the data transported, which OSE Remote does not. In WebSphere V4.0, OSE Remote has been replaced by an HTTP transport which can be encrypted using SSL. Thus there is no need for servlet redirector in WebSphere V4.0.

IIOP

The Internet Inter-ORB Protocol is an industry standard that can be used to provide communication between object-oriented application programs executing on different processors. It is part of the Common Object Request Broker Architecture (CORBA) specification, supporting distributed objects in a TCP/IP network.

CORBA is an architecture for distributed object middleware that separates client and server objects with a formal interface definition, and IIOP defines the message formats and protocols used in a CORBA distributed environment.

SOAP

SOAP is a protocol engineered by IBM, Microsoft, Userland, and DevelopMentor to support remote procedure calls (and other sophisticated requests) over HTTP. It draws from two distinct environments. Built on HTTP and XML, SOAP aims to be as simple as the Web. It targets object-oriented remote procedure calls borrowed from CORBA and Distributed Common Object Model (DCOM). As a general rule, SOAP is targeted for systems where you need to initiate procedures across company boundaries.

Now that you understand the issues involved with selecting an appropriate connection method for your solution, the next step is to select a hybrid Runtime pattern. The WebSphere/Domino Integration design set includes numerous hybrid Runtime designs, providing solution flexibility to address the specific needs of the business process being automated.