Andrew Rivers: BizTalk Error: Failed while delivering a message to a service instance. Message details follow.

I had a strange error in BizTalk this week. I was integrating some changes by the database team on my project, and I got a strange error condition that I had not seen before. The symptoms were as follows:

(Normal functionality): Orchestration extracts an entity from the data access layer, and uses a Start Orchestration shape to launch another orchestration, passing the entity as a parameter.
(Error functionality): The second orchestration shows as started in the BizTalk Admin Console, it can be viewed in Orchestration Debugger, but it never starts processing even its first shape. (The event log blurb will be at the end of the post, because it's a bit bloaty and will detract from the commentary).

So, in my usual troubleshooting-cum-why-is-it-always-me-to-sort-this-out kind of way, I then had to start looking at why this was happening. The strange thing is that nothing much had changed on these orchestrations for about 2 months. It was a stable and well-tested piece of functionality.

What had changed, however, was the structure of the entity that I was getting back. An additional property had been added to the top-level entity that was itself a class containing 3 properties, two strings and a byte array. Nothing controversial here, I thought. I checked out this new class to see if it was serializable (a common thing for non-BizTalk devs to miss off) and it was OK (in fact if it is not serializable then you get a compile rather than a runtime error).

I then put a temporary hack into the data access code to set the new property to null, to see if the creation of this new object was causing the issue and instantly the orchestration started to work as normal. I was starting to get somewhere.

If you look at the error and examine the stack trace you see that there is an index out of bounds error on an array. Now, you may recall that the new object has a byte array, so I thought that this must be the candidate. I then looked at the values being passed through to the byte array and I found that although the byte array was being instantiated it had zero length.

In the end the error was caused by BizTalk not being able to binary serialize / deserialize the state of the object into the orchestration. This only happens if I have a zero-length array. Just to prove it I put in the following line as a temporary measure:

entity.MyProperty.MyByteArray = new byte[] { 0x00 };

This went through the message box OK. I then put in the following instead:

entity.MyProperty.MyByteArray = null;

This also went through. Therefore there is just an issue with a byte array of zero length. I eventually settled on the following:

if (entity.MyProperty.MyByteArray.Length == 0)

{

entity.MyProperty.MyByteArray = null;

}

In Summary

This error was caused by an exception very low down in the BizTalk engine, and lay in the failure to serialize or deserialize the object into the orchestration state. This was caused by the byte array being of zero length (which is legitimate from a .Net point of view), so this may be a fault oin the BizTalk engine.

As a work around, setting the byte array to null when it is empty allowed the orchestration to function.

Exception / Stack Trace

Event Type: Error

Event Source: XLANG/s

Event Category: None

Event ID: 10001

Date: 06/10/2009

Time: 10:14:17

User: N/A

Computer: <>

Description:

Failed while delivering a message to a service instance. Message details follow.

Message ID: 24abb7a4-060d-480b-abdd-c22f70118c11

Service Instance ID: c58613fa-3716-48df-9fc9-edd76cae2f13

Service Type ID: afa69d35-1f0f-7665-4264-b4b78f9abfef

Subscription ID: d7676de9-1e27-4dba-ae5d-223e77c64b50

Body part name:

Service type: <>, <>, Version=<>, Culture=neutral, PublicKeyToken=<>

Exception type: BTXMessageDeliveryException

The following is a stack trace that identifies the location where the exception occured

at Microsoft.BizTalk.XLANGs.BTXEngine.BTXSession._receiveOneMessage(Guid& instanceId, Guid& serviceId, IBTMessage currentMsg)

at Microsoft.BizTalk.XLANGs.BTXEngine.BTXSession.ReceiveMessages(IBTMessage[] messages, Int32 firstIdx, Int32 count)

at Microsoft.BizTalk.XLANGs.BTXEngine.AppDomains.AppDomainRoot.Microsoft.XLANGs.BizTalk.ProcessInterface.IAppDomainStub.ReceiveMessages(Object objMsg)

at Microsoft.XLANGs.BizTalk.CrossProcess.AppDomainStubProxy.Microsoft.XLANGs.BizTalk.ProcessInterface.IAppDomainStub.ReceiveMessages(Object msgs)

at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Int32 methodPtr, Boolean fExecuteInContext, Object[]& outArgs)

at System.Runtime.Remoting.Messaging.StackBuilderSink.PrivateProcessMessage(RuntimeMethodHandle md, Object[] args, Object server, Int32 methodPtr, Boolean fExecuteInContext, Object[]& outArgs)

at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg, Int32 methodPtr, Boolean fExecuteInContext)

at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg)

at System.Runtime.Remoting.Messaging.ServerObjectTerminatorSink.SyncProcessMessage(IMessage reqMsg)

at System.Runtime.Remoting.Messaging.ServerContextTerminatorSink.SyncProcessMessage(IMessage reqMsg)

at System.Runtime.Remoting.Channels.CrossContextChannel.SyncProcessMessageCallback(Object[] args)

at System.Threading.Thread.CompleteCrossContextCallback(InternalCrossContextDelegate ftnToCall, Object[] args)

at System.Threading.Thread.InternalCrossContextCallback(Context ctx, IntPtr ctxID, Int32 appDomainID, InternalCrossContextDelegate ftnToCall, Object[] args)

at System.Threading.Thread.InternalCrossContextCallback(Context ctx, InternalCrossContextDelegate ftnToCall, Object[] args)

at System.Runtime.Remoting.Channels.CrossContextChannel.SyncProcessMessage(IMessage reqMsg)

at System.Runtime.Remoting.Channels.ChannelServices.SyncDispatchMessage(IMessage msg)

at System.Runtime.Remoting.Channels.CrossAppDomainSink.DoDispatch(Byte[] reqStmBuff, SmuggledMethodCallMessage smuggledMcm, SmuggledMethodReturnMessage& smuggledMrm)

at System.Runtime.Remoting.Channels.CrossAppDomainSink.DoTransitionDispatchCallback(Object[] args)