Thursday, October 22, 2009

Oracle Coherence 3.5.2 available

Last week Oracle released Oracle Coherence 3.5.2. The version contains several improvements and enhancements for Oracle Coherence 3.5. The improvements and enhancements are listed here. You can download the new version from here.

More info about Oracle Coherence 3.5, user guides etc, can be found on the Oracle Coherence wiki.

Wednesday, October 21, 2009

SOA Suite 11g: Coordination between two BPEL processes

While scanning the FMW 11g SOA Suite developer guide, I noticed the feature that enables coordination between master and detail BPEL processes by using so- called signals.

As far as I know, this feature is introduced in 11g and is very useful in situations where a parent process has to control the processing of the child processes. And, vice versa, where child processes has to notify their parent process when a specific task is completed. Most of the time a signal is enough and no additional information has to be sent along. Therefore, for example, a BPEL invoke activity with correlation might be a bit too complex for this purpose.

Ok how does it work? The tutorial gives you a clear explanation how to use signaling in Oracle BPEL so I will describe the rough details about how you can use signaling and also some limitations that I discovered while praticing with this feature.

  1. Create a BPEL master detail proces in the composite.
    • Use the process type asynchronous for the master process and the the type one-way for the detail
  2. Add an Invoke activity to the master process to invoke the detail process
    • Open the source view of the BPEL editor and add the following property to the invoke activity:


  3. Add a Wait activity to the master process for demo purposes
  4. Add a Signal activity to the master process
    • Remember the Label value
    • Set the To value to details
  5.  Add a Receive Signal activity to the master process
    • Remember the Label value
    • Set the From value to details
  6.  Add a Receive Signal activity to the detail process
    • Use the Label value used in step 4
    • Set the From value to master
  7. Add a Wait activity to the detail process for demo purposes 
  8. Add a Signal activity to the detail process
    • Use the Label value used in step 5
    • Set the To value to master
  9. You're done! Deploy the composite to the server and test your composite.
The signaling feature also supports correlation to correlate signals between the master and different detail process types. It seems that correlation of signals between different composite master/detail instances are correlated automagically.

Unfortunately, the coordination functionality has some limitations:
  • Labels can not be set dynamically using XPath
  • Correlation labels can not be set dynamically using XPath
  • Only a single signal pair (signal/receive signal) can be used for a unique label
These limitations make it, for example, not possible to coordinate by using signals between a master and multiple detail instances of the same BPEL process type which are invoked in parallel or even sequential..

Oh..I still have to figure out how signaling is implemented 'under the hood'.. However, happy signaling...

Tuesday, October 20, 2009

Oracle SOA Suite 11g: Manipulate the SCA composite name at design time

By default no composite name is set when a SCA composite is executed. For runtime monitoring and tracking purposes it might be useful to set a custom name at design time for your SCA composite.  Especially, when the number of instances increases in production.

By using embedded Java for BPEL components and XPath for Mediator components you are able to manipulate the title of a SCA composite during design time.

XPath for Mediator components:
Use the the following XPath expression in an Assign value dialog when you define a routing rule.

med:setCompositeInstanceTitle(title string)

and use the following target tracking.compositeInstanceTitle.
Note: this property will not appear in the property selection dialog, but can be used though.

Java for BPEL components
Add an Embedded Java activity inside your process flow and add the following function to it:

setCompositeInstanceTitle(title string);

( it is my first real blog-posting. Any comments on the layout are welcome)

Restart blogging

Hi all,

I recently have decided to start blogging again. I don't no exactly why, but most probably it's due to the fact that I want to share my enthusiasm for SOA and Java technology with you. Especially those with an Oracle flavor..

The main topics of this blog will be:
  • Oracle Service Bus
  • Oracle Fusion Middleware 11g
  • Oracle Coherence
  • other SOA and Java topics
  • and best practices on all of the above named topics
Enjoy reading and don't forget to add this blog to your RSS reader :)