Since the last BizTalk Summit, there has been a lot of coverage within the greater BizTalk Community of Windows Azure BizTalk Services – the Azure-backed offering that brings pieces of the core BizTalk Server functionality to the cloud. This is something that QuickLearn had early opportunity to get hands-on with, and also something for which we were able to create labs (even before public availability). At the same time, it’s something that we haven’t really written about until now.
This week, rather than going through specific how-to guidance for pieces of the offering, I instead want to take a step back and look at the offering as a whole, so that we all understand the pieces that are there (and can see the forest through the trees). If you want to follow along, go ahead and download the Windows Azure BizTalk Services Preview SDK.
Once installed, you’ll find that Visual Studio has been juiced up with two additional project templates found under the BizTalk Services heading:
The first project type BizTalk Service allows you to define Itineraries (not in the ESB sense, though they do display a complete message flow, much like ESB), and the configuration for Bridges (much like a BizTalk Pipeline).
The second project type BizTalk Service Artifacts allows you to define schemas and maps (.trfm files, though you can convert your existing .btm files with some limitations using a tool provided at the SDK download link). The mapper is something I’m not going to be discussing any further, and as a result I will instead recommend this excellent blog post on the subject by Glenn Colpaert, and then also the official documentation on the conversion process/limitations.
So we can create these Itineraries, configure these Bridges, and deal with Schemas and Maps, but how does this all fit together within the context of Windows Azure BizTalk Services? To understand the answer to that, we have to first address the three things that Windows Azure BizTalk Services is trying to do:
- Rich Messaging Endpoints (Itineraries + Bridges + Maps)
- BizTalk Adapter Service (Service Bus Relay + Local Helper Service + BIzTalk Adapter Pack)
- Business to Business Messaging (EDI Schemas + All of the Above)
Rich Messaging Endpoints
I’m going to start with the weirdest of the bunch – Rich Messaging Endpoints. The developer experience of this is similar (to a point) to defining an ESB Toolkit itinerary, but only inasmuch as you’re seeing the entire message flow within a single diagram. Here you can define certain sources (FTP/SFTP) for messages, and have them routed through Bridges (similar to Pipelines), and then routed out to certain destinations (for which CBR can be used to route the messages to one or multiple destinations).
In order to specify the settings necessary to connect to those destinations, you often find yourself within a configuration file defining WCF related binding settings directly:
Double-clicking on a bridge within the itinerary will bring up a semi-clone of the Pipeline Designer with a fixed set of components in place (as well as a location to specify maps to execute directly as part of the pipeline):
In terms of integration patterns, the bridges here are giving us a subset of the VETRO pattern (namely the VETR part of it): Validate, Enrich, Transform and Route. Where is the Route part of the equation you might ask? Well, you’ll actually find it in the Properties window for the bridge, by clicking the … button in the Route Ordering Table property:
Here, we can do context-based routing that helps determine the destination for each message coming from the destination (though here, I have only connected a single destination endpoint).
BizTalk Adapter Service
What happens if the list of destinations doesn’t suit me? What if I want to take information from an SFTP drop, transform it into something that I could use to generate a record within a table in SQL, and then directly insert that record into my on-premise system? In that case, I’ll find myself reaching to the BizTalk Adapter Service feature.
This one has a nice list of dependencies that need to be in place before you can even use it (e.g., Windows Server AppFabric, BizTalk Server Adapter Pack), but once you have those, it’s fairly straight-forward to setup.
What it’s really providing is a single WCF endpoint that is exposed over a Service Bus Relay endpoint (and thus accessible from anywhere in the world – even if hosted behind a fairly strict firewall). This single endpoint can be passed messages destined for any number of internal systems that you can setup through the Server Explorer interface within Visual Studio. The BizTalk Team Blog actually had a pretty decent article on the topic back in June that sadly generated 0 comments.
Essentially, this is allowing you to bring your LOB systems into the mix to play along with everything else already mentioned (assuming those LOB systems have WCF adapters included in the BizTalk Adapter Pack).
Business to Business Messaging
The final capability that WABS is bringing to the table is B2B messaging (i.e., EDI). We have the ability through a special portal (still in preview) within the Windows Azure Management interface to create Parties and Agreements a la BizTalk Server on-prem. In fact, the same exact schemas are used to define the X12 messages, so if you’ve already had to do some schema customizations on a per-partner basis for in-house integrations, those same changes can now be brought to the cloud.
Pulling it All Together
Is this replacing BizTalk Server on-premise as we know it? Not quite. We have a lot of the same pieces: Transport (Limited)/Translation (Limited)/Transformation and Context-based Routing (Content-based Routing when using the Enrich stage of the Bridge). We are missing more complete process orchestration with exception handling / transactions / compensation (Orchestrations). We are missing rule-driven injectable logic (Business Rule Engine), among other things (though I’m stopping the list here to avoid debate about similar (but not quite) functionality in Azure in general).
So what do we do with this? Use it to solve integration problems that use a hybrid between cloud-based and on-premise resources (e.g., http://msdn.microsoft.com/en-us/library/windowsazure/hh859742.aspx). Use it when an on-premise BizTalk installation would be overkill for the task, but it can be done happily using the tools available in WABS. Use it to take over the most taxing parts of your B2B processing, leaving BizTalk Server on-premise to do those things it’s great at.
Ultimately, it’s up to you. BizTalk Server 2013 and Windows Azure BizTalk Services together give you the power to decide how to break up your integration work, and how you approach the integration challenges that are thrown your way.
If you haven’t yet given the SDK a download yet, go do it. Though the service is still in preview, the SDK has been available for quite some time now, and great things are right around the corner – so keep your skills sharp.
That’s all for now!