Migrating from mainframe Java app to be generated with CA-GEN statement used to generate COBOL application

[Deva]

Hi All, 

    I am planning to generate a Java application from CA-Gen statements that is currently used to generate COBOL application on mainframe with a Windows Thick client.  I would like to understand 

1. Can CA-Gen generated Java application deployed on both Windows and Linux. ? Is the compatible CA-Gen runtime available on Windows/Linux.
2. Is generating the Web application from the design on Thick client  requires any additional steps or a straight forward activity? 
3. Incase of Java application, what would be tech stack of the application that gets generated, front-end technologies, server-side , Java version etc. 
4. Is there any other item that needs to be considered like additional configuration, design consideration and limitations ? 
5. How performance of the Java application can be tuned ?

Could you please point me to documentation that provides with these information or it would be helpful if someone can help me with these information. 

Thanks in advance .

Regards

Murali 

[Lynn Williams]

Hi Murali,

Firstly if you are using a Host Encyclopedia it cannot generate Java code and you would need to use the Windows Gen Toolset (or Gen Studio for Web View - see below) or install a Gen Client Server Encyclopedia (CSE).

Just to clarify you said you currently have COBOL on mainframe with a Windows thick client. Are you currently using Gen client/server "Windows to z/OS - CICS"? Normally if doing that the client is referred to as a thin client because it does not access the backend application database and the server does that.

 

Gen can generate Java code for applications to run as web applications under an Application Server on both Windows and Linux using Gen Java runtimes. Supported Java versions and Java Application Servers are on this page:

https://techdocs.broadcom.com/us/en/ca-mainframe-software/devops/ca-gen/8-6/technical-requirements/third-party-software-version.html

 

There are 2 types of Gen web client applications - the original Web Generation and later Web View

Some doc. links:

https://techdocs.broadcom.com/us/en/ca-mainframe-software/devops/ca-gen/8-6/tutorial/construction-and-testing-phase/web-generation.html

https://techdocs.broadcom.com/us/en/ca-mainframe-software/devops/ca-gen/8-6/developing/designing/use-gen-studio/work-with-web-view.html

 

If you want to move the COBOL servers to Java they could become Gen Enterprise JavaBeans (EJB or EJB Web Services)

https://techdocs.broadcom.com/us/en/ca-mainframe-software/devops/ca-gen/8-6/distributed-processing/working-with-enterprise-javabeans.html

 

Hope that helps.

Please clarify on the current client/server environment (whether your client is accessing the backend application database or just the server is doing that) and if you want to move both client and server to Java.

 

Thanks

 

Lynn

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Lynn Williams
Senior Principal Support Engineer
Broadcom Software
Australia
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[Deva]

Hi Lynn, 

    Thanks for your response. To answer your question "Are you currently using Gen client/server "Windows to z/OS - CICS"? " - Yes, the Windows client connecting the CICS on z/OS is being used.

Also, another application is on block mode, which uses CICS screens. 

Is there any document which is available that details the process of generating Java application from the CA-GEN statement which were used to generate COBOL application previously. ?  Like what needs to done in case of the block mode application, any UI changes, any CA-Gen statement changes required, any changes required in the EABs etc. 

Also, what would be the suggested architecture to go in this case of moving away from mainframe by generating a JAVA application . 

Thanks & Regards

Murali 

[Lynn Williams]

Hi Murali,

1. For the client/server application migration to Java this is a general article more for the client side: Migrating Gen GUI client-server applications to the Web

The clients can just be regenerated for Java (Web Generation or Web View) and the servers for Java server EJBs per my previous comments above.

The Java server EJBs could connect to the same DB2 database as COBOL servers using JDBC.

When Gen applications are migrated from one platform (OS/programming language etc) to another normally any EABs must be rewritten in the programming language of the new platform. Gen now supports Inline Code so the rewrite could also move the external action blocks to inline code.

Here is a related article: Gen 8.6 server application migration from COBOL to Java and EABs

 

2. For your block mode application application with screens, an extra step is needed to first convert the UI to a client UI for the move to client/server.

There is a "Transform Screen Design into Window" feature in the Navigation Diagram which can convert the screen for an individual PStep to a Window.

For example the Gen sample model online/blockmode Business System CORPORATE_MANAGEMENT.

In Navigation Diagram, use Diagram/Open Window and click on a PStep which does not have a window e.g. MENU, to make the Transform button active and clicking it will show the "Transform Screen Design into Window" option enabled.

If no windows exist at all in the Business System then after using Diagram/Open Window the Transform button will be immediately active and clicking it will show the option "Transform Existing Business System" enabled

https://techdocs.broadcom.com/us/en/ca-mainframe-software/devops/ca-gen/8-6/developing/designing/using-the-toolset/transformation-type-dialog.html

The next step would be to divide your existing PStep code up to separate what can go into the client (no database access) and the server (database access).  Alternatively you could use a fat client which would access the database directly. However as you are moving to client/server in #1 it would probably make sense to use the same design philosophy for this application too.

3. Another factor for the Gen encyclopedia.
On the assumption you are using a Host Encyclopedia, with your move to Java you won't be generating any code on the Host Encyclopedia any more because it can only generate COBOL and the HE would only be used for checkout/checkin (this is unless you are using partner product GuardIEn that enables remote code generation on the HE i.e. it can generate code for non-z/OS platforms including Java).
Therefore unless you move to a Client/Server Encyclopedia (CSE) which would give you centralised Java code generation, you would have to generate all the Java code on the Toolset.

As this would all be a complex multi step process, you may want to discuss it with your Broadcom account rep with a view to a services engagement to assist with detailed planning and a POC.

 

Hope that helps

 

Regards

 

Lynn

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Lynn Williams
Senior Principal Support Engineer
Broadcom Software
Australia
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[Deva]

Hi Lynn, 

     Thanks a lot for your detailed response. I have got an understanding of the steps involved in the migration, I will comeback on this if I need more information. 

Regards

Murali