Jonathan Mezach - All Comments

re: Possible WCF Serialization Issue?

Uros — Fri, 19 Feb 2010 11:57:07 GMT

I also had simillar problems with my service. One of the methods returned an IEnumerable<T>. While testing on windows 7 everything worked ok, but on Windows server machine it got EventId 1023 and a asp.net error.

re: Message based correlation with WF/WCF in .NET 3.5

Hannes Kock — Fri, 29 Jan 2010 08:20:21 GMT

Wohoo!! Thanks alot m8! Saved my year of bad code haha ;D Now I'ts gonna get alot cleaner.

*kisses*

re: Message based correlation with WF/WCF in .NET 3.5

Jonathan Mezach — Tue, 26 Jan 2010 07:32:20 GMT

You'll need to use the ContextMessageProperty class in the System.ServiceModel.Channels namespace (System.WorkflowServices assembly though). You'll need to do the same check in both the GetExistingInstanceContext and the InitializeInstanceContext members of the IInstanceContextProvider interface (or at least that is what I've done). In both operations you will get the message, so you can use the ContextMessageProperty.TryGet operation to determine if its already there (if normal correlation between client and server is used). If it's not there, you can create a new instance of the ContextMessageProperty and use the AddOrReplaceInMessage operation to modify the message so that it contains it. That's all there is to it really.

re: Message based correlation with WF/WCF in .NET 3.5

Hannes Kock — Mon, 25 Jan 2010 16:03:41 GMT

Ah I see. But after wrapping it, I dont get how to actually override the instanceId.

re: Message based correlation with WF/WCF in .NET 3.5

Jonathan Mezach — Fri, 22 Jan 2010 16:22:20 GMT

I've created a class that implements IInstanceContextProvider and given it a constructor that also takes in an instance of IInstanceContextProvider. Then I've implemented an IServiceBehavior which takes the existing IInstanceContextProvider and passes that to the constructor of my own IInstanceContextProvider implementation.

re: Message based correlation with WF/WCF in .NET 3.5

Hannes Kock — Fri, 22 Jan 2010 16:08:07 GMT

Hm, how exactly are you wrapping WorkflowInstanceContextProvider?

re: Message based correlation with WF/WCF in .NET 3.5

Hannes Kock — Fri, 22 Jan 2010 15:53:57 GMT

Ooh nice! First time i´ve seen anyone like me messing around with the instanceId and creating a workflow with an ID you actually want.

I´ve made a custom binding and channel that rests before the securitybinding and creates workflow instances with correct id and attaching the ID to the context (binding inheriting from IContextBindingElement). The problem im in is that when removing the securityheader it all breaks down. Cusom channels is a mess! So i´m looking for alternative solutions. Will check out the IInstanceContextProvider.

What you should do is making the workflow-creating bit alot more visible and extensible. I´ve digged down in the classes creating the workflow in the ReceiveActivity and it aint easy to do anything about.

(me scenario is that i have a custom header already having a transactionId - dont wanna care about a correlation between transactionId and txId for the workflow)

re: Possible WCF Serialization Issue?

Phyo — Mon, 07 Dec 2009 19:10:14 GMT

This post has finally solved my problem. It is 3:00 AM in Singapore here, and I have spent debugging, un-installing .NET, switching machines to machines with different configs, Googling all over the net, books, article. Rootcause is "IList<T>"

Strange enought, the IList<T> will have no problem in Windows 7 Prof with .NET 3.5 SP1. Thats why i did not suspect IList<T> at first.

But thank you so much!

re: Possible WCF Serialization Issue?

Richard Nagle — Fri, 20 Nov 2009 11:02:10 GMT

The same problem occurs if you use IEnumerable<T>.

Changed it to Collection<T> and it works fine.

re: Even better message based correlation

palmeregod — Sun, 01 Nov 2009 18:25:35 GMT

features scheme business include

re: Even better message based correlation

robert ivanc — Sun, 01 Nov 2009 17:09:49 GMT

Excellent work! Have you perhaps published any of this somewhere?

re: Possible WCF Serialization Issue?

Konstantin Zaikin — Tue, 28 Jul 2009 08:00:14 GMT

I had the same problem.

The reason was a ref IList<T> parameter.

As soon as ref was removed, IList<T> parameter worked. No ExecutionEngineException since then.

ref IList<T> is a no-no for WCF.

re: Message based correlation with WF/WCF in .NET 3.5

Robert te Kaat — Wed, 25 Feb 2009 10:10:15 GMT

Remember to implement IEventActivity, etc when creating the CorrelationSequenceActivity, otherwise it can't be used with statemachines. Shouldn't be too hard, since you can forward all calls those interfaces to the receiveactivity, which implements them as wel.

Also the ReceiveActivity is a sequence-activity itself. To make sure one doesn't accidentally add it's childs to the CorrelationSequenceActivity, instead of the ReceiveActivity, you may want to create a custom activitydesigner for the correlationsequenceactivity as well, which only allows a single ReceiveActivity as child.

When using guids as functional keys, mapping-logic can be made generic. However, functional keys are hardly ever guids, thus you may need to specify a mapper for the CorrelationSequenceActivity as well (property?).

re: Message based correlation with WF/WCF in .NET 3.5

Jonathan Mezach — Wed, 25 Feb 2009 09:57:04 GMT

This is something we are still working on, but it's a two-fold problem. You'll need to extract the 'functional key' from the message and then map that 'functional key' to the workflow instance ID. There are several ways of solving this, but we haven't really decided on which way to go. We were thinking of creating a CorrelationSequenceActivity that you can put in your workflow which adds an attached property to the ReceiveActivity. Combined with a designer you could select the property on the input message that is expected by the ReceiveActivity which could then be mapped to an XPath query. I think Marcel is working on such a solution.

This still wouldn't resolve the mapping from the 'functional key' to the instance ID though, so we'll have to think about how to do that.

re: Message based correlation with WF/WCF in .NET 3.5

Robert te Kaat — Wed, 25 Feb 2009 09:49:11 GMT

Niiice! It would be really great if you implement this as generic functionality where the actual 'functional key' of the incoming message can be configured using an xpath-query.

Best place would probably using an attribute on the method-definition in the contract (perhaps there's already some property on the OperationContractAttribute that can be used?). However, at the point of intercepting the message (IDispathMessageInspector:AfterReceiveRequest), WCF hasn't mapped the request to a method yet, so you can't determine which method's attributes to read. Did you find a solution for that as well, or do you scope the 'functional-key-definition' on the contract or even whole service?