BizTalk 2006 : Using BizTalk Framework 2.0 Reliable Messaging (part 1)

Continuing from the previous examples, let's assume that the order processing system notonly needs to update your downstream systems, which are internal to your organization, but also needs to notify a trading partner of the transactions. Let's assume that when an order is placed, you need to order the requested product from a supplier to support your zero inventory objectives. This situation brings about a number of challenges. Assuming for now that the sending and receiving applications are both BizTalk Server applications, you first must ensure that the transaction is completed reliably over inherently unreliable protocols and across network boundaries and firewalls. This is where the BizTalk Framework 2.0 Reliable Messaging scenarios come into play, as shown in Figure 1.

Figure 1. Typical partner exchange scenario

The BizTalk Framework specification is an XML specification that allows reliable messagingover HTTP and other transports. A BizTalk server according to the definition is a server that implements the BizTalk Framework rules and schemas for processing messages to provide a reliable Interchange mechanism over the wire.

In that sense, the product Microsoft BizTalk Server 2006 is a BizTalk server that implementsthe BizTalk Framework 2.0 specification. Of course, having BizTalk Server 2006 on both sides will allow you to implement reliable messaging Interchanges and processes with relatively small effort.

Microsoft BizTalk Server 2006 provides custom pipeline components for sending and receivingBizTalk Framework envelopes. The BizTalk Framework properties are configured through these pipeline components and can also be updated at runtime within an orchestration.

Figure 2 shows the required components (channel/ports and pipelines) to implementan Interchange with BizTalk Framework 2.0. The left side shows the sender configuration, which consists of a static one-way send port to send the business document or message and a static one-way receive port to receive BizTalk Framework 2.0 delivery receipts. The right side shows the receiver configuration, which contains a static one-way receive port to receive the message or business document and a dynamic one-way send port that subscribes (using a filter expression) to the Messagebox for messages that have the property BTS.MessageType with a value of BTF2DeliveryReceipt.

Figure 2. BizTalk reliable messaging configuration

In all four ports, the BizTalk custom pipeline components are used for receiving (Disassemble) and sending (Assemble) BizTalk Framework envelopes.

BizTalk Framework Assembler and Disassembler Pipeline Components

As mentioned before, BizTalk Server 2006 provides custom pipeline components for BizTalkFramework envelopes. The pipeline component that must be configured for messages going out is the Assembler. In our first scenario, only one of the four ports must be configured.