BizTalk Server 2004 Architecture

BizTalk 2004’s core engine contains a messaging component, an orchestration component, and a rule engine. The messaging component communicates with external systems though messages, while the orchestration component guides messages through a defined business process. Orchestrations can call a separate rule engine that applies advanced business logic. Exchange of internal messages among BizTalk components follows a publisher-subscriber model, at the center of which is a SQL Server database called the MessageBox.

Incoming messages are accepted by receive adapters, which allow BizTalk Server to communicate with a variety of sources. BizTalk 2004 and earlier versions ship with adapters that support communication with Web services, via the SOAP adapter, the Windows file system, and SQL Server, for instance. (Developers can build adapters to other systems and many ISVs, such as SAP, offer BizTalk Server adapters.) In the example, the file receive adapter accepts a file-based message from a company’s ERP system; the message contains a purchase order for parts.