Web services transactions, high availability, firewalls and intermediary nodes

You can configure your system to enable propagation of Web Services Atomic Transactions (WS-AT) message contexts and Web Service Business Activities (WS-BA) message contexts across firewalls or outside the WebSphere® Application Server domain. With these configurations, you can distribute web service applications that use WS-AT or WS-BA across disparate systems.

The topologies that are available to you are as follows:

Direct connection

No intermediary node exists in this topology. The client communicates directly with the specificWebSphere Application Server on which the target service is hosted.

HTTP server, such as IBM® HTTP Server

In this topology, the client communicates with an HTTP server, which always routes the client requests and web services transaction protocol messages to a specific WebSphere Application Server. Also, typically you need to configure the HTTP server for web services transactions, that is, configure it to deliver web services transaction protocol messages to the appropriate WebSphere Application Server.

Transactional integrity is assured, because recovery processing occurs after the failed server restarts.

The web service client communicates, through a firewall, with the HTTP server in the demilitarized zone. The configuration of the HTTP server determines where the message is sent in WebSphere Application Server.