BPEL correlation and Message Aggregation

How does BPEL identify which response is for which request?

We all know that there are two major type of processing synchronous and asynchronous and for synchronous processing it uses same TCP connection or in simpler terms single port. So there is no need of correlation for synchronous process.

For Asynchronous processing, BPEL process will usually correlate message using "WS-Addressing", it’s something like web session cookies, which happens internally and we do not need to worry about correlating response messages.

WS-Addressing

The basic question every beginner has is how an asynchronous response gets mapped to the correct instance out of many waiting instances. The answer is, whenever asynchronous service is invoked, Oracle BPM adds a message UID in WS-Addressing headers that flows with SOAP packets, which are used internally by BPEL server to correlate the request/response.

So when does we need manual Correlation?

Below are the scenarios when we will require correlation:

• When external web service doesn’t support WS-Addressing
• When the message travels through several services and the response is solicited by the initial service from the last service directly. For example, Request path is A > B > C and response comes to A directly from C, i.e. C > A
• When receiving unsolicited messages from another system.
• When communicating via files, i.e. When BPEL instance is expecting messages from a third party.

What is correlation?

It is a BPEL technique called correlation set to match or correlate the messages based on content of the message.

It is a collection of properties used by the BPEL process service engine to allow custom correlation.

Before starting with our example we need to understand in which activities do we need correlation. Well the answer is quite self-explanatory, we need correlation whenever data is going out or coming in to the BPEL process, i.e.

• Receive activity
• Reply activity
• Invoke activity
• onMessage branch
• onEvent branch

I will first give the scenario of our example:

you can download the sample from here.
we will have two receive activities in our BPEL process,
One receive will take input as Country Name and Language
Other receive will take input as Country Name and Capital.
The response will have Country Name, Language and Capital.

SOA12C: Getting started – Hello World project OSB

One of the major change in 12C is the integration of OSB IDE within Jdeveloper and hence development and testing of SOA as well as OSB can now be done from within Jdeveloper without the need of installing Eclipse & OSB.

In our previous post we did a Hello World project in SOA, If you have not done that, first do SOA part as in this example we will be calling SOA service, now let’s get started with OSB.

In this sample we will call the Hello World project we created in SOA through business service.

you can download this sample from here.

Let’s first create a new application for service bus:

Name your project accordingly:

SOA12C: Getting started – Hello World project SOA

In the previous post I showed the installationof Oracle SOA in windows 7 machine and to configure integrated domain.

So let’s start with our sample Hello World Project:
you can download this sample from here.

Create a new SOA application:

Enter the Application name and directory location, for the first time you will have to create myworks directory for ex. For my case below is the location I have specified for this project:

SOA 12C installation in Ubuntu

In this post we will see step by step installation process on Ubuntu platform. If you want to see if for Windows, refer my other post.

First step: Install Oracle JDK, 

you can use below commands to install JDK7:

Open terminal and run below commands:

1.             sudo add-apt-repository ppa:webupd8team/java 

2.             sudo apt-get update 

3.             sudo apt-get install oracle-java7-installer

Confirm the Java version:  

Second step: Install Soa Suite 12C

Download the Generic version of installable. From OTN downloads.

go to the downloaded directory, extract the installable and run below command:

java -jar fmw_12.1.3.0.0_soa_quickstart.jar

SOA 12C installation Part 2 - Create Integrated weblogic server default domain

In this post, we see how to create Integrated weblogic server default domain.

This is the second post for the series SOA 12C step by step installation,

So before proceeding with this post you need to read first part.

To create the default domain, go to Window--> Application Server:

Right click on IntegratedWebLogicServer and click on Create Default Domain.

 Enter the domain password and accept defaults.

This domain creation will take some time to finish.

Once you are done with installation and configuration, its time to Get started with 12C development.

SOA 12C installation Part 1 - step by step installation

In this blog we will see how to install SOA Suite 12 C on windows 7.

If you want to see installation steps on Ubuntu platform, refer my other post.

Step 1:

The first step is downloading the SOA 12C installable from Oracle OTN. Enter your Oracle Technology Network account, if you don’t have one you’ll need to create an account.

It includes Oracle BPEL Process Manager, Oracle Human Workflow, Oracle Business Rules, Oracle Mediator, Oracle Service Bus, Technology Adapters Oracle Enterprise Scheduler, SOA Spring Component, Enterprise Manager Fusion Middleware Control, Oracle JDeveloper with SOA IDE extensions and an integrated WebLogic Server and Java DB.

http://www.oracle.com/technetwork/middleware/soasuite/downloads/index.html

Step 2:

While the SOA suite is being downloaded, we can check on JDK versions. A recent version of JDK is required, I am using jdk-7u79-windows-x64.exe, I actually tried with JDK 8 but it SOA didn’t support that version so I had to revert to JDK7. If you don’t have java installed, download and install from below location:

http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html

Step 3:

Install Java and set your Java_HOME environment variable to the installed location, for example, I have installed Java at C:\Oracle\12C\jdk.1.7.0_79

AQ and SOA - Part2 - Posting message to AQ queue from SOA

In the first part we created an AQ queue and posted a sample message into the queue.
In this part we will develop a soa composite to post message into AQ queue.

Before we start creating SOA composite, we first need to configure server resource to access AQ from SOA. We will need a datasource which connects to the database and an AQ outbound connection pool which we will use in our project.
we will create a bpel with exposed webservice to post message to AQ.
In our previous post while object for the queue we gave employee_id, employee_number

create or replace type employee_type as object(

employee_id number,

employee_number varchar2(60),

employee_name varchar2(60)

);

Let’s create a new application for this example:

Create an empty soa project:

Now first we need to create a schema file, as we are going to expose our BPEL as a web service, we will need to enter our input there which will later on be inserted into AQ.

Click on New and select XML Schema: