MigratingESBtoOSB

8/3/2019 MigratingESBtoOSB

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Oracle Service Bus Migration (ESB to OSB)

This article is from the excellent Blog by Marc Kelderman.

See complete article here - http://orasoa.blogspot.com/2008/12/oracle-service-bus-

migration-esb-to-osb.html . It is reproduced here for easy reference only.

Tools that are used for the migration are:

Oracle JDeveloper

Oracle Workshop (Eclipse development)

Oracle JDeveloper

Oracle JDeveloper is use to view the ESB services. It is used to

determine the dependencies of the artefacts that it is using.

Oracle Workshop

Oracle Workshop is used to build and deploy the new OSB services.

Approach

While there is no automatic migration, we need to rebuild the services

in OSB. The approach is as follows.

Reuse the artifacts from ESB as much as possible. This means in

practices that we will reuse the WSDL definitions, schema definitions

and style sheets.

Open in JDeveloper the ESB services and determine the artifacts it isusing;

WSDL files

XSD schema's

Used elements


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Used namespaces

Stylsheets

Filters

Adapters

Describe for each ESB service the artifacts in structured way; for

example in a table format:

Based on these artefacts, the OSB services can be build.

Development environment

Depending on the complexity of the OESB services, a differentsequence of steps should be followed. First of all a project structure

should be in place. In this project structure various components will be

stored.

Projects

The Workspace (OSB Project Structure) should contain one OSB

Configuration Project, give this configuration a name "MyOSBConfig"

and an OSB Project called "MyOSBMigration". The former contains the

server definition for an OSB Server running on :, the latter all project

resources.

Folder Structure

Create for every ESB service, an OSB service with the following

directory structure.

ESBName

Input

WSDL

Schema

Element

Adapter?

DB

DatasourceJNDI


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Query

JMS

JMSConnectionfactory

Queue/Topic

FileDirectory

Filename

Output#1

FilterUsed

WSDL

Schema

Element

Adapter?

WS (MarkifthisaBPELWS)

DB

DatasourceJNDI

Query

JMS

JMSConnectionfactory

Queue/Topic

File

Directory

Filename

Output#2

Folder Description

BusinessService All the business services are located here.

ProxyService All the proxy services are located here.Schema Local schema's in the project are located here.

Transformation Local transformation files (XSLT & XQuery).

Wsdl The interface definitions.

For each ESB project copy the used XSLT files into the transformation


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directory.

Naming Convention

A recommended approach for naming conventions of OSB resources is

to add theprefix `PS_' for Proxy Services, `BS_' for Business Services, `XQ_' for

XQuery

transformations, and append a version indication `_v1r0'. Examples:

Project: CollectOrderInformation

Proxy service: PS_GetOrder_RS_v1r0

PS_GetOrderLines_RS_v1r0

Bus. Service: BS_GetOrder_v1r0

BS_GetOrderLines_v1r0

Proxy Endpoints:

The enpoints of the proxy services will be renamed to

/

Common Schemas

All schemas of the Common data Model are imported in the OSB

project in folder Common/Schema/. All generated or imported WSDLs

should preferably refer to these schemas, potentially importing service

specific schemas in the "Schema" folder of the respective service.

Implementation

Based on the pervious table the OSB service can be build. Execute the

following steps to perform this.

Create the business services

Create the proxy service

Implement the message flow


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Create the business services

Create a new business service for each output definition. If an external

web service is called, import or consume the WSDL definition of that

web service. The same applies if this service is a BPEL process. In this

case some additional changes should be made, this is described in thenext paragraphs..

If you are calling a BPEL process, you could use the BPEL transport

instead of normal http protocol. The BPEL protocol is more efficient

implementation on calling BPEL from OSB.

When the business service is created, the WSDL and schemas are

copied into a folder of your project. After creating the business servicemove the WSDL files to the WSDL directory and the schemas to the

Schema directory or to the Common/Schema directory.

Note: With BEA ALSB 3.0, you should remove the partner link

bindings, otherwise theWSDL is invalid. This is fixed in OSB 10gR3.

Create the proxy service

Create a new proxy service for each input definition. If the service is

based on a interface definition from an external web service is called,import or consume the WSDL definition of that web services.

When the proxy service is created, the WSDL and schemas are copied

into a folder of your project. After creating the proxy service move the

WSDL files to the WSDL directory and the schemas to the Schema

directory or the Common/Schema directory.

Implement the message flowImplementing the flow is the most important step of the migration.

Based on the various output from the ESB, you should route the

message to the various business services.

The most simple one is just create a routing node to call the services.


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Often we need a

transformation call the business service

In the replace action we define

the transformation., this is based on the style sheet of the ESB.

When there are filters defined

in ESB service, this can be replaces in OSB via If-Then actions or

conditional branches actions.

Stylesheets

Note that there can be issues with style sheets. The style sheet isbased on the JDeveloper diagrammer, it is using namespaces and

namespace aliases based on the interface definition of the ESB.

Execute the test action on the replace action of the Oracle Workshop

(Eclipse).

It could be that the style sheet is using Oracle SOA specific extensions

or custom functions, these are not available in OSB. If this is the case,

you should change the style sheet or, which is easier, create a XQuery

transformation.

Deployment and Test

Deploy and test the OSB service, you could use various test scenarios

and tools to perform this.
http://2.bp.blogspot.com/_QolFV9VBHas/SUEGQLW6y6I/AAAAAAAAAEE/kzC3CKsGUR0/s1600-h/snapshot12.pnghttp://4.bp.blogspot.com/_QolFV9VBHas/SUEGP6TBoKI/AAAAAAAAAD8/i3FG9rP0ShA/s1600-h/snapshot11.pnghttp://1.bp.blogspot.com/_QolFV9VBHas/SUEGPgJ_0VI/AAAAAAAAAD0/IgzB36epAOI/s1600-h/snapshot10.png


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Test style sheets and XQueries from Eclipse.

Test business services from the OSB Console.

Test proxy services from the OSB Console.

Use tools such as SoapUI to perform end-to-end tests.

Adapters

Database Adapter

Note that the current version of OSB does not have a DB adapters as

in the ESB.

Therefore you should create the DB adapter in BPEL as a simple

wrapper for this

query. The BPEL process should use the same input and output

schema's and namespaces as generated in the partner link of the DB

adapter. The future version of OSB 10gR3 will have support of the DB

adapter.

JMS Adapter

The OSB has full support of the using JMS messaging.

Import WSDL from BPEL

The ESB service has both the Proxy Service as the Business Service

based on the same WSDL that is `consumed' from the BPEL process.

The steps to create a similar service in OSB are:

1. Import the WSDL from the BPEL process URI (?WSDL) by

consuming froma URI. All included schemas are imported as well

and stored in the samefolder.

2. Leave the WSDL itself in the `WSDL' folder.

3. Drag and drop the service specific schema to the `Schema'

folder thereby automatically changing the reference in the


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WSDL.

4. Change the references from either the WSDL or the service

specific schema to the CDM schemas by changing the

"schemaLocation" property of the "import"tag.

5. Remove the imported CDM schemas from the `wsdl' directory.

6. Add a Business Service in the `BusinessService' directory based

on the imported WSDL.

7. Add a Proxy Service in the `ProxyService' directory based on

that same WSDL.

8. Add a `Routing Node' to the Proxy Service and route to the

Business Service.

Imported WSDL from ESB

The ESB service has a Proxy Service based on a ESB "generated"

WSDL and the Business Service based on the WSDL of a BPEL process.

The steps to create a similar service in OSB are:

1. Import the OESB "generated" WSDL in the Workspace `wsdl'

folder.

2. Add a "service" and a "binding" to that WSDL, because the WSDL

is not well-defined, refer to the PortType of the WSDL.

3. Create a Proxy Service in the `ProxyService' directory based on

that WSDL.

4. Import the WSDL from the BPEL process as described for the

previous service migration; don't forget to move the schemas.

5. Add a Business Service in the `BusinessService' directory based

on the imported WSDL.

6. Add a `PipelinePair' to the Message Flow of the Proxy Service.

7. In the request Pipeline, add a `stage' with a `replace' action,

change the XPath to `.', enter variable `body', in the expression

select the XSL file and add the rootelement of the body (request)

to the `Binding' box, check `replace node contents'.


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8. Same for the response `Pipeline', but obviously for the response

XSL and the response rootelement.

9. Add a `Routing Node' to the Proxy Service and route to the

Business Service.

Documents

MigratingESBtoOSB