Monday, November 25, 2013

Browsing the Meta Data Services Repository of the Oracle SOA/BPM Suite 11g

In this article I explain a handy way to browse the MDS on the SOA/BPM server from JDeveloper, as well as how to download its content using Enterprise Manager, and finally an (as far as I know) undocumented feature to look up artifacts using a browser.

This article has been updated on November 26 to include the option regarding downloading the MDS content.

The Meta Data Services (or MDS for short) of Oracle's SOA/BPM Suite is used to manage various types of artifacts like:
  • Process models created with Process Composer,
  • Abstract WSDL's and XSD's,
  • Domain Value Map's (DVM), and even
  • Artifacts  of deployed composites.

Browsing the MDS from JDeveloper

To find out what actually is deployed in the MDS you can setup an MDS connection within JDeveloper to the server. Such a connection can be handy, for example to verify if replacements of variables in the MDS artifacts are properly done when deploying. Using this connection you can open those artifacts in JDeveloper and check the source.

To create an MDS connection go to the Resource Palette -> New Connection -> SOA-MDS. This will pop-up a tab from which you can create a database connection to the MDS for example the dev_mds schema. Having created the database connection you have to choose the partition to use for the SOA-MDS connection. To be able to check-out processes created whith Composer from the MDS or to save them in the MDS, you create a SOA-MDS that uses the obpm partition. As the name already suggests, this is in BPM-specific partition. To browse the other artifacts I mention above, you use the soa-infra partion, which is shared by both SOA and BPM.

In the figure below you can see two types of connections, above to the soa-infra and below to the obpm partition. In the (soa-infra) apps you can find the reusable artifacts that you have deployed explicitly (like abstract WSDL's, XSD's, EDL's).

What you also see is a deployed-composites folder that shows all composites that have been deployed. When expanding a composite, you will find that all artifacts are shown. This is a much easier way to verify that you do not deploy too many artifacts to the server then by introspecting the SAR file, I would say. Except for .bpmn files (that at the time of writing are not yet recognized by this MDS  browser) you can open all plain text files in JDeveloper.

Downloading the MDS from Enterprise Manager

Now let's assume that you have not been given access to the MDS's DB schema on the environment (perhaps because it is Production), but you do have access to the Enterprise Manager. For this situation my dear colleague Subhashini Gumpula pointed me to the possibility to download the content from the MDS as follows:

soa-infra -> Adminstration -> MDS Configuration  -> and then on the right side of the screen: Export.

This will download a file with its content!

Looking up Artifacts in the MDS Using a Browser

Now let's assume that you also have not been given access to Enterprise Manager on the environment, but you can access using the HTTP protocol. Thanks to my dear colleague Luc Gorrisen I recently learned that you can browse it using part of the URL of the composite, as follows:


For example, to look up the abstract WSDL of some ApplicationService that is used by some StudentRegistration business process, I can use the following URL.


Mind you, this is not restricted to only the WSDL's it is using.

Ain't that cool?!

Wednesday, November 20, 2013

How to Make File-Based MDS in JDeveloper Work for both Windows and Linux

In this article I explain how you  can modify the JDeveloper adf-config.xml file to make it work for both Windows, as well as Linux.

If in a JDeveloper application you point to artifacts in a file based MDS residing in a Windows folder for example "d:\projects\MDS", then JDeveloper will create an new entry in the adf-config.xml file (that you can find in Application Resources -> Descriptors -> ADF META-INF) pointing to the absolute location of that folder:

The problem with this is that if you have other colleagues that use Linux instead of Window, it's not possible to make it work for both by defining some relative location (as you could do with ant), like "../../projects/MDS", so now what?

As in most cases, the solution is so simple that I successfully missed it many times: use an environment variable! What worked was creating an environment variable with name MDS_HOME, and after that I could use it like this:

Problem solved! Such an evironment variable you can create in Windows as well as Linux.

I have not yet fully tested if this works for everything, like deploying with ant, but if it doesn't I expect you can easily fix that by modifying the ant-sca-compile.xml file in your JDeveloper installation folder by adding a property "mds_home" in there as well.

Customizing (or rather Hacking) Oracle BPM 11g Business Exceptions

In this article I explain how you can add custom attributes to Oracle BPM 11g business exceptions. Mind that this is not officially supported.

One of the fun things of giving a training like the Advanced BPM Suite 11g course that I'm running now, is that students ask questions to which you don't know the answer. But hey, you are the teacher, and that won't do, so off you go!

One question asked yesterday was if it is possible to have more attributes on a business exception than just "errorInfo". First question should be: "why do you want that?". Well, let's assume that you at some higher level you want to have access to context information that is only available where the exception is thrown, like a local variable. Of course you can concatenate all info in one long semi-colon separated string or something, but then you probably have to have other logic to transfer that back into something readable.

If you look closely at the definition of a business exception, you will notice that it uses a generated WSDL and XSD. What I did was adding an extra element "name" to the XSD of a business exception with name FailProcess (created for the previous blog article) as follows:

I then restarted JDeveloper to see what would happen, and not totally to my surprise: nothing! As in: it works! I also tried it run-time, and no problem there either, as you can see in the following figure:

One warning though. As the generated XSD clearly states, it should not be altered manually, and any change may be overwritten. It obviously is not a supported hack I show you here, and you should expect that any change of the business exception via the UI will break your code. Therefore let's hope that changes like this in some next version are supported by JDeveloper as well.

Tuesday, November 19, 2013

Why you may consider NOT using the Terminate End Event in Oracle BPM Suite

In this article I explain why you should try to avoid using the Terminate End Event in Oracle BPM 11g.

According to the BPMN specification, the Terminate End Event is supposed to terminate a process instance at the level at which it is raised, including any ongoing activity for sub-processes. But is should not terminate any higher level (parent) process.

With OBPM 11g it works differently (at least up to PS6), as raising a Terminate End Event will actually terminate the composite's instance. Except for human tasks, because as clearly stated in the documentation: "Human tasks are independent from BPMN processes. If you terminate a BPMN process while it runs a user task, the associated human tasks keeps running independently". The reason is that the human workflow engine runs separately from the BPM engine.

In the process below this will result in the situation that the Review Data task will still show in Workspace, while the associated process instance is already terminated. That was not the original intention of this model.

This flow shows what actually happens:

Conclusion: before considering using the Terminate End Event be well aware of its behavior. Consider alternate types of modeling, like raising a business exception that is caught by the parent process, which then uses an Update Task activity to withdraw all human tasks before actually ending. In this way you can prevent any human doing accidentally doing work for nothing.

Such a model would look like this: