Low Latency BizTalk

Here are some link to achieve low latency in BizTalk Solutions:

http://threaddump.blogspot.com/2005/03/optimizing-biztalk-for-latency.html

SOAP Adapter Configuration and Tuning Parameters:
http://msdn.microsoft.com/en-us/library/aa560822.aspx

Configuration Parameters that Affect Adapter Performance
http://msdn.microsoft.com/en-us/library/aa561380.aspx

Optimizing BizTalk Server Performance
http://technet.microsoft.com/en-us/library/cc594552.aspx

FIX: Slow performance on startup when you process a high volume of messages through the SOAP adapter in BizTalk Server
http://support.microsoft.com/kb/886966

BizTalk 2006 SOAP Adapter (Web Service call) in Messaging Only Scenario
http://blogs.digitaldeposit.net/saravana/post/2006/12/20/BizTalk-2006-SOAP-Adapter-(Web-Service-call)-in-Messaging-Only-Scenario.aspx

Adding Custom SOAP Headers

1) Add a Property Schema to the solution:
2) The Target namespace of our property schema, should be http://schemas.microsoft.com/BizTalk/2003/SOAPHeader.
3) Add an element to this property schema, for example MyCustomSoapHeader. Set the Property Schema Base to MessageContextPropertyBase.

4) In orchestration, inside the Construct Message shape of the message that we send to web service, add a Message Assignement.

5) Inside Message Assignement, assign our custom soap header to the message context property:

See more information at:
http://msdn.microsoft.com/en-us/library/ms946927.aspx