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vaibhav gs
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Joined: 05 Apr 2018
Posts: 17
Location: INDIA
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Hi, we are currently working on a requirement to replace an existing mainframe screen with a webpage without interruption of underlying business logics. No tools are provided in this regards. We are also not planning to use any IMS/CICS regions for this activity.
We have gone through many approaches and many were ruled out as they need some tools/ CICS/ IMS regions to be procured.
With the knowledge that we have, we have come up with a plan. Can you please check the attached flow diagram and give your opinion on the feasibility of the same.
Please note that this is for Online mainframe screen migration to a web page.
Open to learn and get my understandings correct wherever applicable. |
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Robert Sample
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Joined: 06 Jun 2008
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Location: Dubuque, Iowa, USA
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| It is not unusual for mainframe CICS programs to have business logic embedded (for validating data fields, for example) built into the code. Your approach seems to ignore this possibility. |
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vaibhav gs
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Joined: 05 Apr 2018
Posts: 17
Location: INDIA
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True Robert, i do agree with you.
But my basic underlying rule is not to use any CICS/ IMS regions to perform this. Hence we have ignored this possibility with CICS/IMS.
Sorry, feel free to correct me if my understanding on your statement is wrong. |
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Robert Sample
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| What is the current mainframe screen using? |
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vaibhav gs
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Joined: 05 Apr 2018
Posts: 17
Location: INDIA
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Current mainframe screen is using IMS region and COBOL code.
We are planning to move to web based screen. |
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Robert Sample
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| So is there any business logic in the COBOL code (such as screen validation of input data)? If so, how are you going to replicate that with the web page / Java code? That logic would not be in the batch programs so if you don't capture it in the web page / Java code, you will be losing functionality by converting. |
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vaibhav gs
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Joined: 05 Apr 2018
Posts: 17
Location: INDIA
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Yes Robert true, we are planning to handle it for now but try to think of screen functionalities later point of time.
Apart from that can you please tell me if this approach sounds good or weird
Thanks for your time. |
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Pedro
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Joined: 01 Sep 2006
Posts: 2547
Location: Silicon Valley
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I do not understand the JCL part... are you going to submit a job and somehow wait for it to complete? I think the asynchronous aspect is a weakness in the design.
Rather than have REXX submit a job and wait for it, I think the rexx should allocate whatever files are needed and use CALL command to call the COBOL program. |
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Rohit Umarjikar
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Joined: 21 Sep 2010
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Location: NYC,USA
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| Quote: |
Hi, we are currently working on a requirement to replace an existing mainframe screen with a webpage without interruption of underlying business logics. No tools are provided in this regards. We are also not planning to use any IMS/CICS regions for this activity.
We have gone through many approaches and many were ruled out as they need some tools/ CICS/ IMS regions to be procured. |
This is usually done for real-time work unless you are currently kicking off any batch jobs through this , are you?
You can call a SP from your Web application and then Batch jobs still can be triggered.
Look for more options here as how to do so. |
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Gary Jacek
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Joined: 17 Dec 2007
Posts: 64
Location: Victoria, BC, Canada
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You mention CICS and IMS, but your diagram shows only DB2 as a data store for a REXX stored procedure.
Does the COBOL program currently interact with IMS databases or other DB2 tables?
If applicable, is the IMS database managed by an IMS Control Region?
This could very much complicate direct access to the data.
If the COBOL program currently runs in IMS message processing regions, have you considered publishing it as a service, for consumption by your web page server? This would retain the existing business logic in the COBOL program and the IMS control region would handle the database access, logging, lock management and data recoverability.
Have a look at IMS Explorer for Development (free tooling) to see if this fits your requirement.
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Gary Jacek
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Joined: 17 Dec 2007
Posts: 64
Location: Victoria, BC, Canada
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Two attempts to paste a URL for E4D here have failed.
So use that famous search engine called G**gle and search for "how to publish ims transaction as a service".
Good luck. |
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vasanthz
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Joined: 28 Aug 2007
Posts: 1742
Location: Tirupur, India
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You can probably replace the first 3 blocks with IBM HTTP server running on Mainframe and use CGI scripts to execute REXX/JCL etc.. and return back the results to web page.
IBM HTTP Server ---> CGI scripts --> REXX/JCL
It does the same thing as the first 3 blocks, but the advantage is your application would reside completely on Mainframe without external server requirement and the complexity in interfacing it. |
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vaibhav gs
New User
Joined: 05 Apr 2018
Posts: 17
Location: INDIA
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| Pedro wrote: |
I do not understand the JCL part... are you going to submit a job and somehow wait for it to complete? I think the asynchronous aspect is a weakness in the design.
Rather than have REXX submit a job and wait for it, I think the rexx should allocate whatever files are needed and use CALL command to call the COBOL program. |
True Pedro, I was also considering this but due to the number of teams that use my application, this async operation did not bother us a lot.
Thanks much for your time and will keep you posted on any fruitful outcome. Cheers! |
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vaibhav gs
New User
Joined: 05 Apr 2018
Posts: 17
Location: INDIA
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| Rohit Umarjikar wrote: |
| Quote: |
Hi, we are currently working on a requirement to replace an existing mainframe screen with a webpage without interruption of underlying business logics. No tools are provided in this regards. We are also not planning to use any IMS/CICS regions for this activity.
We have gone through many approaches and many were ruled out as they need some tools/ CICS/ IMS regions to be procured. |
This is usually done for real-time work unless you are currently kicking off any batch jobs through this , are you?
You can call a SP from your Web application and then Batch jobs still can be triggered.
Look for more options here as how to do so. |
Yes Rohit true for real time access but users are internal business team.
Sure will read the links and will let you know if any fruitful outcome from it.
Thanks for your time.
Cheers! |
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vaibhav gs
New User
Joined: 05 Apr 2018
Posts: 17
Location: INDIA
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| Gary Jacek wrote: |
You mention CICS and IMS, but your diagram shows only DB2 as a data store for a REXX stored procedure.
Does the COBOL program currently interact with IMS databases or other DB2 tables?
If applicable, is the IMS database managed by an IMS Control Region?
This could very much complicate direct access to the data.
If the COBOL program currently runs in IMS message processing regions, have you considered publishing it as a service, for consumption by your web page server? This would retain the existing business logic in the COBOL program and the IMS control region would handle the database access, logging, lock management and data recoverability.
Have a look at IMS Explorer for Development (free tooling) to see if this fits your requirement.
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Yes, COBOL program access few DB2 tables for fetching and saving some part of information. But not IMS databases, thanking god for that  lol
This is completely new to me "publishing the service" and it sounds good. Will have to go through the links that you have given and will try to make it useful to us.
Thanks for suggesting this approach, cheers! |
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vaibhav gs
New User
Joined: 05 Apr 2018
Posts: 17
Location: INDIA
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| vasanthz wrote: |
You can probably replace the first 3 blocks with IBM HTTP server running on Mainframe and use CGI scripts to execute REXX/JCL etc.. and return back the results to web page.
IBM HTTP Server ---> CGI scripts --> REXX/JCL
It does the same thing as the first 3 blocks, but the advantage is your application would reside completely on Mainframe without external server requirement and the complexity in interfacing it. |
Hi Vasanthz, the first suggestion that was given by one of our expertforum experts is the "CGI".
But I am still not able to get full picture on how to make it as working model. I still agree this is very useful solution but could not proceed much further without a right direction.
Feel free to suggest me with any article that would have helped you to assimilate the knowledge about CGI scripts. |
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