Handling incoming data streams in pipeline components in BizTalk Server 2004/2006

Published on : Aug 23, 2006

Category : BizTalk Server



When you write custom disassembler code for pipeline components, you must make sure that you do not close the incoming data stream in the custom disassembler code. The incoming stream from the input message is a shared resource. The incoming stream is also used by the message body tracking component in the BizTalk Server message engine. If you either implicitly or explicitly close the incoming stream, tracking data may be lost. Therefore, you cannot examine the data in the Health and Activity Tracking (HAT) tool in BizTalk Server. Additionally, you must make sure that you read from the incoming data stream until the end of the stream is reached. For example, if the custom code makes a read request for 300 KB of data and the code only receives 34 KB of data, do not assume that the end of the stream has been reached. The custom code must always read from the incoming stream until 0 bytes is returned. At the end of a custom pipeline component, make sure that you “rewind” the data stream pointer back to the start of the stream. Typically, you do this just before returning the data stream near the end of the custom component logic. For example, use the following code. msgDataStream.Seek(0, SeekOrigin.Begin); return msgDataStream; If you do not do this and the stream is read to the end in the current component, the next component receives what appears to be an empty stream because the data stream pointer was not rewound. This can cause unexpected parsing and validation errors in follow-on pipeline components.


1. Don’t close the stream Implicitly or Explicitly 2. Read till the end of the stream, until 0 bytes is returned.