Information about handling incoming data streams in pipeline components in BizTalk Server 2004 or in BizTalk Server 2006 (905517)

INTRODUCTION

When you write custom disassembler code for pipeline components in Microsoft BizTalk Server 2006 or in Microsoft BizTalk Server 2004, 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.

MORE INFORMATION

You must not close the incoming data stream object. 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.

myDataStream.Seek(0, SeekOrigin.Begin);
																	 return myDataStream;

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.

For more information about how to handle incoming data streams in BizTalk Server 2006, visit the following Microsoft Developer Network (MSDN) Web site:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/bts06coredocs/html/a1b7c4f7-99ba-4bfa-89ab-1fabfe0845d1.asp

For more information about BizTalk Server 2004, visit the following Microsoft Web site:

http://www.microsoft.com/biztalk/

For more information about how to create seekable streams in the Microsoft .NET Framework, visit the following Microsoft Developer Network (MSDN) Web site:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconbasicfileio.asp

For more information about custom pipeline processing in BizTalk Server 2004, visit the following MSDN Web site:

http://www.microsoft.com/belux/nl/msdn/community/columns/claessens/custompp.mspx