Using the BizTalk Messaging Engine
The following diagram illustrates the architecture of the Messaging Engine. It shows a scenario in which a message is received by an adapter and submitted into BizTalk Server.
Each adapter has its own instance of a TransportProxy object that it uses to interact with the Messaging Engine. Adapters perform work against the Messaging Engine in batches, which are processed atomically. A batch is a collection of operations such as SubmitMessage, SuspendMessage, or DeleteMessage.
The following is the sequence of events for the scenario where an adapter submits a message to the Messaging Engine:
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The adapter creates a new message and connects the data stream to the message.
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The adapter gets a new batch from the Messaging Engine.
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The adapter adds the message to the batch to be submitted.
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The batch is committed and queued up on the Messaging Engine thread pool.
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The Messaging Engine thread pool starts processing the new batch.
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The message is processed in the receive pipeline.
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The receive pipeline produces zero or more messages. Pipelines can consume messages providing they do not return any errors. Receive pipelines can produce more than one message; typically this happens when the dissassembler component disassembles a single interchange into many messages. Typically the receive pipeline normalizes the submitted message into XML.
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The message(s) produced by the pipeline will be processed in the mapper if mapping is configured.
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The message(s) are published to the Message Agent or to the MessageBox database.
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The Messaging Engine calls back the adapter to notify it of the outcome of the batch of work.
