I, For One, Welcome our New Cloud Overlords

I’m trying really hard to not pay attention to PDC today, but, damn them and their interesting announcements!  The “Cloud OS” turned out to be Azure.  Good stuff there.  “BizTalk Services” are dead, long live .NET Services.    Neat that you have both Java and Ruby SDKs for .NET Services.

Also, we got a full release of the Microsoft Federation Gateway (whitepaper here) and a preview of the Microsoft Service Connector (announcement here).  For companies tackling B2B scenarios with a myriad of partners, these technologies may offer a simplified route.

Ok, back to real work.  Stop distracting me with your sexy cloud products.

Technorati Tags: Azure, .NET Services

Reason #207 Why the BizTalk WCF Adapter is Better Than the SOAP Adapter

In writing my book, I’ve had a chance to compare the two BizTalk service generation wizards, and I now remember why the BizTalk Web Services Publishing Wizard (ASMX) drove me nuts.

Let’s look at how the WCF Wizard and ASMX Wizard take the same schema, and expose it as a service.  I’ve purposely included some complexity in the schema to demonstrate the capabilities (or lack thereof) of each Wizard.  Here is my schema, with notations indicating the node properties that I added.

Now, I’ve run both the BizTalk Web Services Publishing Wizard (ASMX) and the BizTalk WCF Service Publishing Wizard (WCF) on this schema and pulled up WSDL of each.   First of all, let’s look at the ASMX WSDL.  Here is the start of the schema definition.  Notice that the “Person” element was switched back to “sequence” from my XSD definition of “all.”  Secondly, see that my regular expression no longer exists in the “ID” node.

We continue this depressing journey by reviewing the rest of the ASMX schema.  Here you can see that a new schema type was created for my repeating “address” node, but I lost my occurrence boundaries.  The “minOccurs” is now 0, and the “maxOccurs” is unbounded.  Sweet.  Also notice that my “Status” field has no default value, and the “City” node doesn’t have a field restriction.

 

So, not a good story there.  If you’ve thoughtfully designed a schema to include a bit of validation logic, you’re S.O.L.  Does the WCF WSDL look any better, or will I be forced to cry out in anger and shake my monitor in frustration?  Lucky for me (and my monitor), the WCF wizard keeps the ENTIRE schema intact when publishing the service endpoint. 

There you go.  WCF Wizard respects your schema, while the ASMX Wizard punches your schema in the face.  I think it’s now time to take the ASMX Wizard to the backyard, tie it to a tree, and shoot it.  Then, tell your son it “ran away but you got a brand NEW Wizard!”

Technorati Tags: BizTalk, WCF

That’s "MR" Skeptical Blogger to You!

A couple weeks back I answered some interview questions regarding my impressions of Microsoft’s Oslo.  One of my answers found its way into an article you can read on ComputerWorld entitled Microsoft eyes Oslo as game-changer for application development.   It’s a good article with some interesting perspective.  You’ll find my quote on page three.  I wouldn’t say that I’m skeptical of the intentions of Oslo, but I AM just curious to see how they pull it off.  So, maybe I’m skeptical of their implementation!  The point I was trying to make is that expansive models aren’t easy to either design or maintain, and attempts that I’ve seen so far to synchronize the model with the implementation have been lacking.  We’ll see if the Oslo repository and “M” language are actually game changers.  Here’s hoping.

I’m not making it to PDC this year, but since I live close by, I hope to pop in on some extracurricular events.

In-Memory BizTalk Resequencer Pattern

I was asked a couple days ago whether it was possible to receive a related but disjointed set of files into BizTalk Server and both aggregate and reorder them prior to passing the result to a web service.  Below is small sample I put together to demonstrate that it was indeed possible.

You can find some other resequencer patterns (most notably, in the Pro BizTalk Server 2006 book), but I was looking for something fairly simple and straightforward.  My related messages all come into BizTalk at roughly the same time, and, there are no more than 20 in a related batch.

Let’s first take a look at a simplified version of the schema I’m working with.

I’ve highlighted a few header values.  I know the unique ID of the batch of related records (which is a promoted value), how many items are in the batch, and the position of this individual message in the batch sequence.  These are crucial for creating the singleton, and being able to reorder the messages later on.  The message payload is a description of a document.  This same schema is used for the “aggregate” message because the “Document” node has an unbounded occurrence limit.

I need a helper component which stores, sorts and combines my batch messages.  My class starts out like this:

Notice that I’m using a SortedDictionary class which is going to take the integer-based sequence number as the “key” and an XML document as the “value.”  The SortedDictionary is pretty cool in that it will automatically sort my list based on the key.  No extra work needed on my part.  I’ve also got a couple member variables that hold values universal to the entire batch of records.  I accept those values in the constructor.

Next, I have an operation to take an inbound XML document and add it to the list.

You can see that I yank out the document-specific “SequenceID” and use that value as the “key” in the SortedDictionary. 

Next I created an “aggregation” function which drains the SortedDictionary and creates a single XML message that jams all the “Document” nodes into a repeating collection.

As you can see, I extract values from the dictionary using a “for-each” loop and a KeyValuePair object.  I then create a new “Document” node, and suck out the guts of the dictionary value and slap it in there.

Now I can build my BizTalk singleton.  Because we promoted the “BatchID” value, I can create a correlation set based on it.  My initial receive shape takes in a “BatchRecord” message and initializes the correlation set.  In the “Set Variables” Expression Shape, I instantiate my loop counters (index at 1 and maximum based on the “BatchCount” distinguished field), and the helper class by passing in the “BatchID” and “BatchCount” to the constructor.  In the “AddDocToBatch” Expression Shape, I set my message equal to a variable of type “XmlDocument”, and pass that variable to the “AddDocumentToDictionary” method of my helper class.

Next, I have a loop where I receive the (following correlation) “BatchRecord” message, once again call “AddDocumentToDictionary”, and finally increment my loop counter.

Finally, I create the “BatchResult” message (same message type as the “BatchRecord”) by setting it equal to the result of the “GetAggregateDocument” method of the helper class.  Then, I send the message out of the orchestration.

So, if I drop in 5 messages at different times and completely out of order (e.g. sequence 3, 5, 4, 2, 1), I get the following XML output from the BizTalk process:

As you can see, all the documents show up in the correct order.

Some parting thoughts: this pattern clearly doesn’t scale as the number of items in a batch increases.  Because the batch aggregate is kept in memory, you will run into issues if either (a) the batch messages come in over a long period of time or (b) there are lots of messages in a batch.  If either case is true, you would want to consider stashing the batch records in an external storage (e.g. database) and doing the sorting and mashing at that layer.

Any other thoughts you wish to share?

Technorati Tags: BizTalk

Splitting Delimited Values in BizTalk Maps

Today, one of our BizTalk developers asked me how to take a delimited string stored in a single node, and extract all those values into separate destination nodes.  I put together a quick XSLT operation that makes this magic happen.

So let’s say I have a source XML structure like this:

I need to get this pipe-delimited value into an unbounded destination node.  Specifically, the above XML should be reshaped into the format here:

Notice that each pipe-delimited value is in its own “value” node.  Now I guess I could chained together 62 functoids to make this happen, but it seemed easier to write a bit of XSLT that took advantage of recursion to split the delimited string and emit the desired nodes.

My map has a scripting functoid that accepts the three values from the source (included the pipe-delimited “values” field) and maps to a parent destination record.

Because I want explicit input variables  to my functoid (vs. traversing the source tree just to get the individual nodes I need), I’m using the “Call Templates” action of the Scripting functoid.

My XSLT script is as follows:

<!-- This template accepts three inputs and creates the destination
"Property" node.  Inside the template, it calls another template which
builds up the potentially repeating "Value" child node -->
<xsl:template name="WritePropertyNodeTemplate">
<xsl:param name="name" />
<xsl:param name="type" />
<xsl:param name="value" />

<!-- create property node -->
<Property>
<!-- create single instance children nodes -->
<Name><xsl:value-of select="$name" /></Name>
<Type><xsl:value-of select="$type" /></Type>

<!-- call splitter template which accepts the "|" separated string -->
<xsl:call-template name="StringSplit">
<xsl:with-param name="val" select="$value" />
</xsl:call-template>
</Property>
</xsl:template>

<!-- This template accepts a string and pulls out the value before the
designated delimiter -->
<xsl:template name="StringSplit">
<xsl:param name="val" />

<!-- do a check to see if the input string (still) has a "|" in it -->
<xsl:choose>
  <xsl:when test="contains($val, '|')">
   <!-- pull out the value of the string before the "|" delimiter -->
   <Value><xsl:value-of select="substring-before($val, '|')" /></Value>

     <!-- recursively call this template and pass in
value AFTER the "|" delimiter -->
     <xsl:call-template name="StringSplit">
     <xsl:with-param name="val" select="substring-after($val, '|')" />
     </xsl:call-template>

  </xsl:when>
  <xsl:otherwise>
      <!-- if there is no more delimiter values, print out
the whole string -->
      <Value><xsl:value-of select="$val" /></Value>
   </xsl:otherwise>
</xsl:choose>

</xsl:template>

Note that I use recursion to call the “string splitter” template and I keep passing in the shorter and shorter string into the template.   When I use this mechanism, I end up with the destination XML shown at the top.

Any other way you would have done this?

Technorati Tags: BizTalk

Interview Series: Four Questions With … Matt Milner

I’m continuing my series of interviews where I chat with a different expert in the Connected Systems space and find out their thoughts on technology.

This month, we’re having a powwow with Matt Milner.  Matt’s a Microsoft MVP, blogger, instructor and prolific author in MSDN Magazine.  Matt’s a good sport who was subjected to my stupidest stupid question so far and emerged unscathed.

Q: You’ve recently delivered a series of screencasts for Microsoft that explain how to get started with WCF and WF. What has the reaction to these offerings been so far? Do you believe that these efforts make development in WCF and WF more approachable? Why do you think that uptake of these technologies has seemed a been a bit slower than expected?

A:  The response to the screencasts has been great; with a lot of positive comments from developers who have viewed them.  I think the smaller bits of information are easily digestible and the goal is definitely to make the technologies more accessible to .NET developers.  I think uptake on Windows WF is slower than hoped because many developers have not seen the “killer application” of the technology to really help them understand how it can save them time. 

Q: There are a wide range of technologies that you’ve written about and researched (e.g. BizTalk Services, WCF, WF, BizTalk Server).   Which technology are you truly excited to work with and learn more?  For the traditional BizTalk developer, which technology would you recommend they spend free time on, and why?

A:  For me, the combination of WF and WCF is going to be huge moving forward.  These are primary underlying technologies for BizTalk Services and other platform plays coming from Microsoft.  Both technologies will be used in many different products from Microsoft and other vendors as they are key enabling technologies.  Understanding these two technologies on top of the core .NET language fundamentals will provide developers with a solid base for developing in the next generation Microsoft application platform.

Q: In addition to your day job, you’re also an instructor for Pluralsight (with a course coming up in Irvine, CA) which means that you are able to watch many folks grasp BizTalk for the very first time.    What are some common struggles you see, and what sort of best practices do you teach your students that you wish seasoned, self-taught BizTalkers would adhere to?

A:  One of the biggest struggles for most students new to BizTalk is getting your head wrapped around the message oriented approach.  Most .NET developers focus on objects with methods and parameters and BizTalk doesn’t work that way.  The other two key things that trip people up are a lack of knowledge around programming XML, schemas and XSLT which are important technologies in BizTalk Server; and the sheer number of tools and concepts that surround BizTalk Server and make it an extremely powerful server platform.

Q [stupid question]: In addition to being an instructor, you also are a consultant.   This means that there are countless opportunities to introduce yourself to new people and completely fabricate a backstory which baffles and intrigues your audience.  For instance, you could walk onto a brand new project and say “Hi, before doing IT consulting, I toiled in the Bolivian underground as an oil wrestler with a penchant for eye gauges.   I currently own a private farm where I raise boneless chickens and angry ferrets who provide inspiration for a romantic thriller I’m writing on weekends.”  Ok, give me your best fake back-story that you could use for your upcoming BizTalk class. 

A:  Over the summer I lived my dream of opening a booth at the Minnesota State Fair where food “on-a-stick” is a common theme.  My family and I perfected the Peanut Butter and Jelly sandwich-on-a-stick, pancakes on-a-stick, and deep-fried huevos rancheros on-a-stick.  The whole family worked at the booth and got to meet people from all over Minnesota including celebrities Al Franken and Jesse “the body” Ventura.

Stay tuned for next month’s interview where we can digest some of the announcements and information from the upcoming PDC.

Technorati Tags: BizTalk