SAP meet Azure Service Bus – EAI/EDI December 2011 CTP
The Azure Service Bus EAI/EDI December 2011 CTP has been out for about 2 weeks at the time of this blog post. As soon as I saw the Service Bus Connect feature in the documentation I wanted to try and hook up the Service Bus to SAP. The organization that I work for utilizes SAP to support many of its core business processes. We are also heavily invested in BizTalk Server when integrating SAP with other Corporate Systems. For the past 5 years much of my work experience has involved integration with SAP. So much that I had the opportunity to write a couple chapters on BizTalk-SAP integration in the Microsoft BizTalk 2010 Line of Business Systems Integration book.
Integrating with SAP is of great interest to me both personally and professionally. I like the challenge of taking two different types of systems that would seemingly be impossible to integrate yet find a way to do it. I also enjoy the expression on SAP consultants face when you take a Microsoft product and successfully execute operations inside their system like creating customer records or creating Work Orders.
Using the Service Bus Connect feature is not the only way of bridging your On-Premise Line of Business Systems with external parties via cloud based messaging technologies. Within the past year Microsoft also introduced a feature called BizTalk Server 2010 AppFabric Connect for Services. This tool allows for BizTalk to expose an endpoint via a Service Bus Relay. I have also used this mechanism to communicate with SAP via a Mobile Device and it does work.
There are a few differences between Service Bus Connect and AppFabric Connect for Services. Some of these differences include:
- Any message transformations that need to take place actually take place in the Cloud instead of On Premise. When integrating with SAP, you never want to expose SAP schemas to calling clients. They are ugly to say the least. In this scenario we can expose a client friendly, or conical schema, and then transform this message into our SAP request in Azure.
- AppFabric Connect for Services utilizes a full deployment of BizTalk in your environment where as Service Bus Connect only requires the BizTalk Adapter Pack when communicating with SAP. All message transformations and orchestration takes place On Premise and the cloud (Azure Service Bus) is basically used as a communication relay.
When connecting to On-Premise Line of Business Systems, both methods require the BizTalk Adapter Pack to be installed On-Premise. The BizTalk Adapter Pack is included in your BizTalk license. Licensing details for Service Bus Connect have not been released at the time of this writing.
The following walkthrough assumes you have some experience with the new Service Bus CTP. If you haven’t looked at the CTP before I suggest that you visit a few of the following links to get more familiar with the tool:
- Introduction to the Azure Service Bus EAI/EDI December 2011 CTP by Kent Weare (me)
- Azure Service Bus Connect EAI and EDI “Integration Services” CTP by Rick Garibay
- Azure AppFabric Labs–EAI, Service Bus in the Cloud by Mick Badran
- How the Azure ServiceBus EAI & EDI Labs SDK impacts Microsoft integration by Sam Vanhoutte
- Azure Service Bus EAI/EDI December 2011 CTP – Content Based Routing by Mikael Håkansson
Also it is worth pointing out another blog post written by Steef-Jans Wiggers where he discusses Oracle integration with Service Bus Connect.
Building our Application
- The first thing we need to do is to create a new ServiceBus – Enterprise Application Integration project. In my case I am calling it HelloSAP.
- Since we know that we want to communicate with an On-Premise LOB system like SAP we need to Add a ServiceBus Connect Server. We can do this by accessing Server Explorer, right mouse clicking on ServiceBus Connect Servers and then selecting Add Server. When prompted we can provide a host name of localhost since this is a local environment.
- We now can expand our Service Bus Connect Servers hierarchy. Since we want to build an SAP interface we can right mouse click on SAP and select Add SAP Target…
- If you have ever used the BizTalk Adapter Pack before, you are now in familiar territory. This is (almost) the same wizard that we use to generate schemas when connecting to SAP systems via BizTalk. There is a subtle difference in the bottom left corner called Configure Target Path which we will discuss in a few moments. If you are unfamiliar with this screen you are going to need some help from your SAP BASIS Admin to provide you with the connection details required to connect to SAP. Also if you are interested in further understanding everything that is going on in this screen I recommend you pick up the BizTalk LOB book that I previously talked about as I discuss the different aspects of this wizard in great detail. (ok..no more shameless plugs)
- We now want to select the type of interface that we want to interact with. For the purpose of this blog post I am going to select a custom IDOC that is used when submitting timesheets from our field personnel. In my case, the version of SAP that I am connecting to is 700 so that is why I am selecting the ZHR_CATS IDOC that corresponds to this version. Once again, if you are unsure you will need to speak to your BASIS Admin.
- Notice how we cannot click the OK button after establishing a connection to SAP and selecting an IDOC? We now need to create a Target Path. Creating a Target Path will provide the Bridge from the Azure Service Bus into SAP. Click the Configure button to continue.
- Assuming that we have not been through this exercise before we need to select Add New LobRelay from the Select LOB Relay to host the LOB Target: dropdown list.
- Another dialog box will appear. Within this dialog box we need to provide our CTP Labs namespace, a Relay path, Issuer name and key. For Relay path:, we can really provide whatever we want here. It will essentially make up the latter portion of URI for the Endpoint that is about to be created.
- Now we are are prompted to Enter LOB Target sub-path. Once again this value can be whatever we want to choose. Since the HR Timesheet module inside of SAP is often called CATS I will go ahead and use this value here.
- Now with our Target Path configured we are able to select the OK button to proceed.
- Inside Server Explorer we now have an entry underneath SAP. This represents our End Point that will bridge requests coming from the cloud to SAP.
- At this point we haven’t added any artifacts to our Enterprise Application Integration project that we created earlier. This is about to change. We need to right mouse click on our SAP endpoint and then select Add schemas to HelloSAP…
- We will now get prompted for some additional information in order to re-establish a connection to SAP so that we can generate Schemas that will enable us to send a message to SAP in a format that it is expecting. You may also notice that we aren’t being prompted for any SAP server information. In the Properties grid you will notice that this information is already populated because we had previously specified it when using the Consume Adapter Service Wizard.
- Inside our solution, we will now discover that we have our SAP schemas in a folder called LOB Schemas.
- For the purpose of this blog post, I have created another folder called Schemas and saved a Custom Schema called CloudRequest.xsd here. This is the message that our MessageSender application will be sending in once we test our solution. (BTW: I do find that the Schema editor that is included in BizTalk is much more intuitive and user friendly than this one. I am not a big fan of this one)
- We now need to create a Map, or Transform, to convert our request message into a request that SAP will understand.
- Next we need to add a Bridge on to the surface of our Bridge Configuration. Our Bridge will be responsible for executing our Map that we just created and then our message will get routed to our On-Premise end point so that our Timesheet can be sent to SAP.
- We now need to set the message type that we expect will enter the bridge. By double clicking on our TimeSheetBridge we can then use the Message Type picker to select our Custom message type: CloudRequest.
- Once we have selected our message type, we can then select a transform by clicking on the Transform – Xml Transform box and then selecting our map from the Maps Collection.
- Before we drag our LOB Connection shape onto our canvas we need to set our Service Namespace. This is the value that we created when we signed up for the CTP in the Azure Portal. To set the Service Namespace we need to click on any open space, in the Bridge Configuration canvas, and then look in the Properties Page. Place your Service Namespace here.
- We are now at the point where we need to wire up our XML One-Way Bridge to our On-Premise LOB system. In order to do so we we need to drag our SAP instance onto the Bridge Configuration canvas.
- Next, we need to drag a Connection shape onto the canvas to connect our Bridge to our LOB system.
- The next action that needs to take place is setting up a Filter Condition between our LOB Shape and our Bridge. You can think of this like creating a subscription. If we wanted to filter messages by their content we would be able to do so here. Since we are interested in all messages we will just Match All. In order to set this property we need to select our Connection arrow then click on the Filter Condition ellipses.
- If you have used the BizTalk Adapter Pack in the past you will be familiar with SOAP Action headers that need to be be set in your BizTalk Send Port. Since we don’t have Send Ports per say, we need to set this action in the Route Action as part of the One-Way Connection shape. In the Expression text box we want to put the name of our Operation which is http://Microsoft.LobServices.Sap/2007/03/Idoc/3/ZHR_CATS//700/Send wrapped with single quotes ‘ ’. We can obtain this value by selecting our Service Bus Connect Server endpoint and then viewing the Properties page. Within the Properties page there is an Operations arrow that can be expanded on and we will find this value here. In the Destination (Write To) we want to set our Type to Soap and our Identifier to Action.
- There is one last configuration that needs to take place before enable and deploy our service. We need to set our Security Type. We can do so by selecting our SAP – ServiceBus Connect Server instance from Server Explorer. Then in the Properties Page, click on the SecurityType ellipses. Determining which Security type to use will depend upon how your SAP instance ahs been configured. In my case, I am using ConfiguredUsername and I need to provide both a Username and Password.
- With our configuration set, we can now enable our SAP – ServiceBus Connect Server instance by right mouse clicking on it and then selecting Enable.
- We can now deploy our application to Azure by right mouse clicking on our Visual Studio solution and selecting Deploy.
- In order to test our application we can use the MessageSender tool that is provided with the CTP Samples/Tools. It will simply allow us to submit EDI, or in this case XML, messages to an endpoint in the Azure Service Bus. In order to successfully submit these messages we need to provide our Service Namespace, Issuer Name, Shared Secret, Service Bus endpoint address, a path to our XML file that we want to submit and indicate that we are submitting an xml document. Once we have provide this information we can hit the enter key and provided we do not have errors we will see a Message sent successfully message.
Note: In the image below I have blocked my Shared Secret (in red) for privacy reasons.
- If we launch our SAP GUI we should discover that it has received a message successfully.
- We can then drill down into the message and discover the information that has been posted to our timesheet
While testing, I ran into an exception. In the CATSHOURS field I messed up the format of the field and sent in too much data. The BizTalk Adapter Pack/SAP Adapter validated this incoming data against the SAP schema that is being used to send messages to SAP. The result is a message was returned back to the MessageSender application. I thought that this was pretty interesting. Why? In my solution I am using a One-Way bridge and this exception is still being propagated to the calling application. Cool and very beneficial.
Overall the experience of using Service Bus connect was good. There were a few times I had to forget how we do this in BizTalk and think about how the Service Bus Connect does it. An example of this was the SOAP Action Headers that BizTalk developers are use to manipulating inside of Send Ports. I am not saying one way is better than the other but they are just different. Another example is the XML Schema editor. I find the BizTalk editor to be much more user friendly.
While I am not convinced that the current state of Service Bus Connect is ready for primetime (they have CTPs for a reason), I am very impressed that the Microsoft team could build this type of functionality into a CTP. For me personally, this type of functionality(connecting to On Premise LOB Systems) is a MUST HAVE as organizations start evolving towards Cloud computing.