Soa Suite 10.1.3.3 - ESB, BPEL - Nice-to-knows, pitfalls

I've been checking out the different capabilities and new features of the Adapter-framework in ESB and BPEL for some weeks now and came across some nasty pitfalls, nice-to-knows, ... which I would like to share with you.

Of course I would like to share thoughts, opinions and start discussions on these topics.

ESB:

• How to define xsd-validation on file-adapter (validate payload at runtime-option isn't available in file adapter) : In the ESB console, select the routing service which is invoked after the inbound file adapter. See the "Definition" tab. The validation option is in the "Operation Details" section. (with thanks to Ronald)

• Define error-handling on file-adapter for erroneous files: use the 'rejectedMessageHandlers' endpoint property which you need to define manually in the esb-file (for more information have a look at the technical note about error handling http://www.oracle.com/technology/products/integration/adapters/pdf/Adapter_TN_004_Adapter_ErrorManagement.pdf
  

BPEL:

• Inserting master-detail data using DB Adapter functionality : Referring to my experiences so far it's best best way to make use of stored procedures instead of the toplink mappings file. I am mainly using the stored procedures because the tooling support in Jdeveloper (wizards, toplink ui), I still miss a good ui for the toplink support. Also it is easy to give the task to create an PL/SQL api to the PL/SQL developers that are working on a certain application. (with thanks to Orjan)

• [Error ORABPEL-10007]: unresolved messageType for "{http://schemas.oracle.com/bpel/extension}RuntimeFaultMessage": When you've defined an empty bpel process (which is best practice to do the brain-work) you will face this issue when defining fault-handling inside your bpel-process. To solve this error you need to import the RuntimeFault.wsdl inside the adapter you're using. Following import statement needs to be added:

• Best practices when invoking Bpel Processes from different UI's (Flex, JSF, ...) : Many thanks to Hajo for his explanation: It is best practice to use the default ways to invoke a BPEL process – create a WSDL that maps to WSIF binding in a controlled environment and to a SOAP/HTTP binding in a more B2B type of scenario. A call to the BPEL API would be a “custom” solution that needs way more governance to communicate with fellow developers and to maintain properly, when compared to the straightforward standard way. . For more details see OTN Thread: http://forums.oracle.com/forums/thread.jspa?messageID=2329384&#2329384

• Use multiple sources in transform-activity: In 11g a new feature has been added to be able to use multiple sources using bpel 2.0 (bpel:doXslTransform(string, node-set, (string, object)*)). The workaround in 10.1.3.3 is by using the params-approach => http://blogs.oracle.com/rammenon/2007/05/07. Or by using an assign-activity with append-functionality to add the variable inside your source-target and in the same assign-activity add the process-xslt functionality to call your xsl to populate the source with the target-information.

Invoking Web Services from Database:

• Call an esb service using the UTL_HTTP package => ORA-29266: end-of-body reached => make sure to pass variables using String-notation instead of Character-notation

Interesting New Features in 10.1.3.3 :

• Controlling the Size of a Rejected Message (10133technotes.pdf):
  You can now control the size of a rejected message by specifying the following
  endpoint property for the inbound File/FTP adapter partner link.
  In this example, you reject 100 lines from the file since the actual file is too large.
  oracle.tip.adapter.file.debatching.rejection.quantum=”100”

• ESB Endpoint Properties : e.g. ability to add RejectedMessageHandler to file adapter services

Enhancement Requests:

• Ability to validate xml payload at runtime on Adapter-level instead of on domain level or routing service level
• Ability to add xsi:nil attribute using xsl-functionality in transform-activity
• File-adapter: Ability to skip columns besides skipping rows + ability to use special characters in column headers

Well that's it for now ... feel free to share thoughts, comments, etc.

Working With BlazeDS Beta 1

Last week we successfully ported an AIR application from amfphp to BlazeDS. The code for this application was almost completely generated by a new generator we're working on (coming soon!). With the announcement of BlazeDS, we kinda shelved our php generator and redirected our efforts in doing the same thing for BlazeDS. In the process, we put together our own version of the blazeds.war file that ships with BlazeDS beta 1, which we use as the starting point for all our BlazeDS projects. Here's a list of the changes we've made:

• Modified the context.xml found in the META-INF folder - the packaged one was producing Valve Errors
• Added the missing my-streaming-amf channel to services-config.xml, which I found in the BlazeDS samples war's config file
  
• Incorporated the latest Flex 3 Compiler Module files to allow server-side compilation of mxml files
• Created a very simple java class and a corresponding destination which will verify Blaze backend functionality
• Created a very simple Flex application that calls the above java class function test(string)
• Added 2 jars to WEB-INF, one is crazedTemplate.jar, which our new codegenerator (coming soon) uses, the other is sharpertools.jar, which the jar requires.
  

You can choose to go ahead and just use the application as is. It's only been tested on Tomcat / Win / OSX 10.5.2. If you don't intend on using our generator (coming soon!) to generate your java and AS3 Classes then you can go ahead and delete the 2 jars mentioned above. I really like this separation of compiler and essentially what was FDS. When FDS was originally released, it did both runtime compiles as well as Remoting, Messaging, Proxy and Managed Data Services. In our case, we never deployed anything that required runtime compilation AND furthermore, with each subsequent Flex release (2.01, Hotfix 1, 2 and 3), converting FDS projects that were set to compile on the server wasn't trivial. So we stopped using it. If I was super Java savvy I might have been able to figure out what parts I could yank out of my FDS application, but generally it seemed better to just leave it alone.

Now, with Blaze and the compiler war being separate, I've gone through the web.xml in this project and put comments to show which pieces are required by the compiler module and which pieces are required by Blaze. To get this back to being a pure Blaze non-Flex 3 Compiler Module, you'd just need to remove the appropriately marked sections from the web.xml and then remove all folders and files from WEB-INF/flex with the exception of:

• services-config.xml
• remoting-config.xml
• proxy-config.xml
• messaging-config.xml
  

Some of our clients have asked what the differences exactly are between BlazeDS and LCDS (prev. known as FDS). If you do enough research on the web, you can find several answers. From what I've seen, here's some differences I've found so far:

• BlazeDS does not support the RTMP Channel typically used by LCDS for data push (RTMP typically means firewall port challenges all around anyway!)
• BlazeDS does support AMF Streaming which offers data push like RTMP, however not nearly as scalable (100's vs 10000's of concurrent users)
• BlazeDS does support proxy so you can bypass the all too familiar sandbox issues when accessing remote data where no crossdomain.xml is present
• BlazeDS does not come packaged with the Compiler Module
• BlazeDS does not have managed dataservices. This means that you don't need the fds.swc (DataService & [Managed]) in your flex projects.. you will use either Consumer, Producer or RemoteObject Classes
• BlazeDS does support AMF3, RemoteClasses & Messaging with a "lite" version of push via amf streaming
  

To download the blazeBlank application click here. (as new builds of Flex 3 and BlazeDS are released I'll try to keep this application updated). This application currently uses Flex 3 Beta 3 and BlazeDS Beta 1. Be sure to visit the url /{context}/TestApp/Main.mxml to ensure that the application is working properly. (i.e. http://localhost:8600/blazeBlank/TestApp/Main.mxml)

Column Aliases in BI Publisher

Problem:

If you create a dataset and build your SQL-query by Query Builder or type it manually, you have to watch out that you do not use column aliases like ‘FEED’.

See example below:

SQL-query:

select BI_TABLE.FEED as FEED,
      BI_TABLE.FEEDBACK as FEEDBACK,
      BI_TABLE.APPLICATION_ID as APPLICATION_ID,
      BI_TABLE.NAME as TYPE_NAME,
      BI_TABLE.DESCRIPTION as TYPE_DESCRIPTION
from HR. BI_TABLE;

XML-file:



Internet Explorer seems to perform a strict XML validation. He gives you following error:


Solution:

Replace all column aliases with names like ‘FEED’ and your problem is solved. See solution below:

SQL-query:

select BI_TABLE.FEED as COLUMN_01,
      BI_TABLE.FEEDBACK as COLUMN_02,
      BI_TABLE.APPLICATION_ID as APPLICATION_ID,
      BI_TABLE.NAME as TYPE_NAME,
      BI_TABLE.DESCRIPTION as TYPE_DESCRIPTION
from HR. BI_TABLE;

XML-file:


Note: You can use ‘FEED’ as name for database tables but remember, not for column aliases!!!

Working With BlazeDS Beta 1

Last week we successfully ported an AIR application from amfphp to BlazeDS. The code for this application was almost completely generated by a new generator we're working on (coming soon!). With the announcement of BlazeDS, we kinda shelved our php generator and redirected our efforts in doing the same thing for BlazeDS. In the process, we put together our own version of the blazeds.war file that ships with BlazeDS beta 1, which we use as the starting point for all our BlazeDS projects. Here's a list of the changes we've made:

• Modified the context.xml found in the META-INF folder - the packaged one was producing Valve Errors
• Added the missing my-streaming-amf channel to services-config.xml, which I found in the BlazeDS samples war's config file
  
• Incorporated the latest Flex 3 Compiler Module files to allow server-side compilation of mxml files
• Created a very simple java class and a corresponding destination which will verify Blaze backend functionality
• Created a very simple Flex application that calls the above java class function test(string)
• Added 2 jars to WEB-INF, one is crazedTemplate.jar, which our new codegenerator (coming soon) uses, the other is sharpertools.jar, which the jar requires.
  

You can choose to go ahead and just use the application as is. It's only been tested on Tomcat / Win / OSX 10.5.2. If you don't intend on using our generator (coming soon!) to generate your java and AS3 Classes then you can go ahead and delete the 2 jars mentioned above. I really like this separation of compiler and essentially what was FDS. When FDS was originally released, it did both runtime compiles as well as Remoting, Messaging, Proxy and Managed Data Services. In our case, we never deployed anything that required runtime compilation AND furthermore, with each subsequent Flex release (2.01, Hotfix 1, 2 and 3), converting FDS projects that were set to compile on the server wasn't trivial. So we stopped using it. If I was super Java savvy I might have been able to figure out what parts I could yank out of my FDS application, but generally it seemed better to just leave it alone.

Now, with Blaze and the compiler war being separate, I've gone through the web.xml in this project and put comments to show which pieces are required by the compiler module and which pieces are required by Blaze. To get this back to being a pure Blaze non-Flex 3 Compiler Module, you'd just need to remove the appropriately marked sections from the web.xml and then remove all folders and files from WEB-INF/flex with the exception of:

• services-config.xml
• remoting-config.xml
• proxy-config.xml
• messaging-config.xml
  

Some of our clients have asked what the differences exactly are between BlazeDS and LCDS (prev. known as FDS). If you do enough research on the web, you can find several answers. From what I've seen, here's some differences I've found so far:

• BlazeDS does not support the RTMP Channel typically used by LCDS for data push (RTMP typically means firewall port challenges all around anyway!)
• BlazeDS does support AMF Streaming which offers data push like RTMP, however not nearly as scalable (100's vs 10000's of concurrent users)
• BlazeDS does support proxy so you can bypass the all too familiar sandbox issues when accessing remote data where no crossdomain.xml is present
• BlazeDS does not come packaged with the Compiler Module
• BlazeDS does not have managed dataservices. This means that you don't need the fds.swc (DataService & [Managed]) in your flex projects.. you will use either Consumer, Producer or RemoteObject Classes
• BlazeDS does support AMF3, RemoteClasses & Messaging with a "lite" version of push via amf streaming
  

To download the blazeBlank application click here. (as new builds of Flex 3 and BlazeDS are released I'll try to keep this application updated). This application currently uses Flex 3 Beta 3 and BlazeDS Beta 1. Be sure to visit the url /{context}/TestApp/Main.mxml to ensure that the application is working properly. (i.e. http://localhost:8600/blazeBlank/TestApp/Main.mxml)

Flex - Rules of Thumb

When you're building JEE Applications, you always need to apply to a given set of rules, best practices.

When you need to take a decision in which technology to use to build your new application with, you need to be able to deliver each rule of tumb with this technology.

Rules of thumb that need to tackled:
- Isolation
- Simplicity of UI and Model
- Clear separation of concerns
- Responsive & intuitive User Interface

Delivering Rules of Thumb using FDMS

The rules of thumb mentioned for Adobe Flex Integration, can be delivered using Flex Data Management Services.

1. Isolation :

Isolate handling of state, presentation, action and communication

State:

• Assembler Class holds all necessary information regarding state-handling
• Pull-mechanism of Data Services assures all clients have up-to-date information

Presentation:

• Java DTO (Data Transfer Objects) are automatically mapped to Action Script DTO’s

Action:

• Actions are immediately called on the Assembler Class that holds all needed business logic and CRUD-methods

Communication:

• Communication between client and server are handled on server-side using the Assembler Class

2. Simplicity of UI and Data Model:

Keep UI and data model code as simple as possible

• The User Interface only defines the lay-out of the different objects and data management is performed by the Data Services
• Data Model is provided using Web Service Stubs created on the deployed Bpel Processes and Data Transfer Objects

We still need to manually create an Action Script DTO object for each POJO we’re using in our Web Services.

3. Clear separation of concerns:

Decouple and make programming tasks parallel so they can be carried out by different people

• Assembler Class will be defined for each designated web service stub
• Data Transfer Objects will be defined in ActionScript for each used object-definition in the Assembler-class

4. Responsive & intuitive User Interface:

Provide a very responsive user experience with clear feedback and zero latency

• Provided using Data Services Management using push-mechanism
• Use managed DTO-components so each event is known to the Data Services
• Use validation-framework for client-side validation
• Use conflict resolution API for exception handling

Working With BlazeDS Beta 1

Last week we successfully ported an AIR application from amfphp to BlazeDS. The code for this application was almost completely generated by a new generator we're working on (coming soon!). With the announcement of BlazeDS, we kinda shelved our php generator and redirected our efforts in doing the same thing for BlazeDS. In the process, we put together our own version of the blazeds.war file that ships with BlazeDS beta 1, which we use as the starting point for all our BlazeDS projects. Here's a list of the changes we've made:

• Modified the context.xml found in the META-INF folder - the packaged one was producing Valve Errors
• Added the missing my-streaming-amf channel to services-config.xml, which I found in the BlazeDS samples war's config file
  
• Incorporated the latest Flex 3 Compiler Module files to allow server-side compilation of mxml files
• Created a very simple java class and a corresponding destination which will verify Blaze backend functionality
• Created a very simple Flex application that calls the above java class function test(string)
• Added 2 jars to WEB-INF, one is crazedTemplate.jar, which our new codegenerator (coming soon) uses, the other is sharpertools.jar, which the jar requires.
  

You can choose to go ahead and just use the application as is. It's only been tested on Tomcat / Win / OSX 10.5.2. If you don't intend on using our generator (coming soon!) to generate your java and AS3 Classes then you can go ahead and delete the 2 jars mentioned above. I really like this separation of compiler and essentially what was FDS. When FDS was originally released, it did both runtime compiles as well as Remoting, Messaging, Proxy and Managed Data Services. In our case, we never deployed anything that required runtime compilation AND furthermore, with each subsequent Flex release (2.01, Hotfix 1, 2 and 3), converting FDS projects that were set to compile on the server wasn't trivial. So we stopped using it. If I was super Java savvy I might have been able to figure out what parts I could yank out of my FDS application, but generally it seemed better to just leave it alone.

Now, with Blaze and the compiler war being separate, I've gone through the web.xml in this project and put comments to show which pieces are required by the compiler module and which pieces are required by Blaze. To get this back to being a pure Blaze non-Flex 3 Compiler Module, you'd just need to remove the appropriately marked sections from the web.xml and then remove all folders and files from WEB-INF/flex with the exception of:

• services-config.xml
• remoting-config.xml
• proxy-config.xml
• messaging-config.xml
  

Some of our clients have asked what the differences exactly are between BlazeDS and LCDS (prev. known as FDS). If you do enough research on the web, you can find several answers. From what I've seen, here's some differences I've found so far:

• BlazeDS does not support the RTMP Channel typically used by LCDS for data push (RTMP typically means firewall port challenges all around anyway!)
• BlazeDS does support AMF Streaming which offers data push like RTMP, however not nearly as scalable (100's vs 10000's of concurrent users)
• BlazeDS does support proxy so you can bypass the all too familiar sandbox issues when accessing remote data where no crossdomain.xml is present
• BlazeDS does not come packaged with the Compiler Module
• BlazeDS does not have managed dataservices. This means that you don't need the fds.swc (DataService & [Managed]) in your flex projects.. you will use either Consumer, Producer or RemoteObject Classes
• BlazeDS does support AMF3, RemoteClasses & Messaging with a "lite" version of push via amf streaming
  

To download the blazeBlank application click here. (as new builds of Flex 3 and BlazeDS are released I'll try to keep this application updated). This application currently uses Flex 3 Beta 3 and BlazeDS Beta 1. Be sure to visit the url /{context}/TestApp/Main.mxml to ensure that the application is working properly. (i.e. http://localhost:8600/blazeBlank/TestApp/Main.mxml)

Flex - Rules of Thumb

When you're building JEE Applications, you always need to apply to a given set of rules, best practices.

When you need to take a decision in which technology to use to build your new application with, you need to be able to deliver each rule of tumb with this technology.

Rules of thumb that need to tackled:
- Isolation
- Simplicity of UI and Model
- Clear separation of concerns
- Responsive & intuitive User Interface

Delivering Rules of Thumb using FDMS

The rules of thumb mentioned for Adobe Flex Integration, can be delivered using Flex Data Management Services.

1. Isolation :

Isolate handling of state, presentation, action and communication

State:

• Assembler Class holds all necessary information regarding state-handling
• Pull-mechanism of Data Services assures all clients have up-to-date information

Presentation:

• Java DTO (Data Transfer Objects) are automatically mapped to Action Script DTO’s

Action:

• Actions are immediately called on the Assembler Class that holds all needed business logic and CRUD-methods

Communication:

• Communication between client and server are handled on server-side using the Assembler Class

2. Simplicity of UI and Data Model:

Keep UI and data model code as simple as possible

• The User Interface only defines the lay-out of the different objects and data management is performed by the Data Services
• Data Model is provided using Web Service Stubs created on the deployed Bpel Processes and Data Transfer Objects

We still need to manually create an Action Script DTO object for each POJO we’re using in our Web Services.

3. Clear separation of concerns:

Decouple and make programming tasks parallel so they can be carried out by different people

• Assembler Class will be defined for each designated web service stub
• Data Transfer Objects will be defined in ActionScript for each used object-definition in the Assembler-class

4. Responsive & intuitive User Interface:

Provide a very responsive user experience with clear feedback and zero latency

• Provided using Data Services Management using push-mechanism
• Use managed DTO-components so each event is known to the Data Services
• Use validation-framework for client-side validation
• Use conflict resolution API for exception handling