Migrating iSeries (AS/400) Legacy Applications to Azure
Published Oct 04 2019 02:42 PM 23.8K Views
Microsoft

The platform was first introduced as the AS/400 (Application System/400) on June 21, 1988 and later renamed to the eServer iSeries in 2000. The IBM System i is IBM's previous generation of midrange computer systems for IBM i users, and was subsequently replaced by the IBM Power Systems in April 2008.

 

One feature that has contributed to the longevity of the IBM System i platform is its high-level instruction set (called TIMI for "Technology Independent Machine Interface" by IBM), which allows application programs to take advantage of advances in hardware and software without recompilation.

The AS/400 has been a very robust platform in the past decades, offering the compatibility mentioned above, which has allowed customers to keep building up their legacy applications with no or minimum migration effort involved.

 

But times have changed.

 

Now, one of the biggest decisions IT managers have to make is how and where to run data center applications in order to lower costs and increase business agility.

 

There are multiple options, including server virtualization, internal clouds, public clouds, and external private clouds.

 

Skytap and Microsoft just announced a new collaboration to bring Skytap’s IBM POWER-based cloud service to Microsoft Azure.

 

Once running on Azure, legacy applications can be enhanced with web services, mobile capabilities, AI and IoT. Legacy workloads will seamlessly span old and new hardware and software architectures, giving the ability to extend the life of traditional systems and increase their value by modernizing with Azure services.

 

One important argument to move out of proprietary hardware and software platforms is that applications have been developed using legacy programming languages like RPG and COBOL, and programmers with these skillsets are retiring.

 

The new generation of software programmers don’t know RPG nor COBOL and are not interested in knowing them at all. Nowadays, they graduate from school knowing modern web technologies used by large software companies like Microsoft, Google, Facebook and Amazon. Such technologies include JavaScript, NodeJS, PHP, React, Angular, SQL Server, Cosmos DB and MySQL, to name a few.

 

AS/400 RPG and COBOL, like any other proprietary programming languages, use other software tools developed exclusively for running on their native platform, in this case, the AS/400, such as DDS (Data Description Specifications) to design screen formats as well as data files (physical and logical).

The screen format specifications allow programmers to embed business rules into the screen format itself, making it tightly coupled to the business rules. If at the same time, the RPG or COBOL code contain more business rules, that makes applications even more complicated to maintain.

 

All of these technical issues are contrary to the modern development practices, where the functional, independent-object approach is applied to the different layers of the development cycle: user interface (UI), web server and database. Each layer should be independent of the rest of the application.

 

“Low Code” development tools like SYNON(CA 2E) or LANSA have been used to build legacy applications for the iSeries platform, designing the applications in their respective IDEs but generating at the end RPG or COBOL code.

 

And finally, the most of the legacy systems were big monoliths, running either as a single process or a small number of processes spread across a handful of servers. They have slow release cycles and are updated relatively infrequently. At the end of every release cycle, developers package up the whole system and hand it over to the ops team, who then deploys it and monitors it.

 

Today, these big monolithic legacy applications are slowly being broken down into smaller, independently running components called microservices. Because microservices are decoupled from each other, they can be developed, deployed, updated and scaled individually. This enables you to change components quickly and as often as necessary to keep up with today’s rapidly changing business requirements.

 

Microsoft has built an ecosystem of partners who can provide a specific solution for AS/400 users, based on their current requirements and needs:

 

  1. Lift-And-Shift. RPG, COBOL and CL applications are migrated and executed in a very similar environment as the AS/400. It takes few weeks to move applications and data to Azure. The applications can still be maintained in their respective legacy source code, or in the converted code which is C for business rules, and JAVA for User Interface.
  2. Modernization. The RPG/COBOL/CL/SYNON/LANSA source code or specs of the legacy applications is transformed into either JAVA, C#, PHP or Javascript. In the case of SYNON/LANSA, the migration is done based on the application specs, not from the RPG/COBOL code generated by those tools.
  3. Migration of DB2 databases (including any physical and logical files) to Cosmos DB, Azure SQL, SQL Server, MySQL, MariaDB or any other relational database.
  4. Implementation of microservices, containers and orchestrators.

 

Migrating iSeries (AS/400) Applications to AzureMigrating iSeries (AS/400) Applications to Azure

 

At the end, the customer can choose which operating system (Windows, Linux), Web Server (NodeJS, IIS, Apache) and database (SQL Server, Azure SQL Database, MySQL, MariaDB) they want to use.

 

The retirement of RPG/COBOL programmers won’t be an issue anymore. Both development teams, RPG/COBOL and JAVA/C#/C/PHP/Javascript programmers, can work together to maintain the applications and do the knowledge transfer easily.

 

Advantages:

 

  • Reduce hardware and software infrastructure costs
  • Modernize legacy source code, user interface and databases
  • Improve the maintenance and deployment of the converted applications
  • Smooth transition from the AS/400 to Azure

 

For more information, please contact the AS/400 Division at the Azure Global CAT Engineering team.

20 Comments
Copper Contributor

Hi , Can I get more details on this, i am interested  in knowing the complete process, conversion and hosting of traditional AS400 application on to Azure.

 

Copper Contributor

I would be very much interested in some more details of this offering as well.

Microsoft

Hi, Jan.

We will be glad to jump into a call with you to review the solutions we have for moving AS/400 workloads to Azure.

Regards.

Copper Contributor

Hi Ricardo.  How would would someone get a hold of your team?  Working with a partner whose customer is running AS400 on prem and looking to move to Azure.  Would be a fun project to upgrade the entire environment.

Microsoft

Hi, Valeriep.

I would be glad to speak with you about the interesting options we have to move AS/400 workloads to Azure.

Copper Contributor

Hi, does this solution include infinite I?

Microsoft

Hi, mvervoorn.

Yes. Infinite i is one of the options we have in our Partner ecosystem.

We have very interesting solutions, not only to migrate to Azure but also to modernize legacy applications.

 

Copper Contributor

Hello! I’d also like to get in touch with your team. I have a county that needs to move off AS/400 and could use some guidance. Thanks!

Copper Contributor

Hola Ricardo, I would also like to know more about how to migrate legacy IBM AS/400 systems to Azure in partnership with Microsoft's Services.

I work for IBM GTS / Cloud Migration and Modernization (now re-named Kyndryl). Can we setup a call to know what intial information would you need to estimate this type of migration project? / my email is andres.chavarria@ibm.com

Microsoft

Hola, Andres.

Thank you very much for reaching out.

We will be glad to share with you the different options that we offer to our AS/400 customers to migrate/modernize their legacy applications.

I will set up a call with you.

Best regards.

Copper Contributor

Hi , Can I get more details on this, i am interested  in knowing the complete process, conversion and hosting of traditional AS400 application on to Azure.

 

Don Richardson

Copper Contributor

Hi Ricardo, 

Thank you for the explanation. But, could you pls provide me the name of the MS partners who work with this kind of migration (AS400 to Azure)? Thank you for your feedback, Best regards, 

Copper Contributor

Hi Team,

 

I would really need help working on AS400. My client has a Host system as AS400 and one of the application is on-perm and they wanted to migrate all of it to Azure. I have done some research and need more details on how to migrate and what are the pre-requisites... Thanks for your help in advance

Copper Contributor

Hi Ricardo, 

Very informative content you shared.. Experts of legacy systems are retiring, But it doesn’t mean there are no experts on legacy systems; they are just hard to find. Cloud services must be designed, implemented, and managed carefully, per distinct business needs and available resources.

 

 

Microsoft

Hi, Abel.

I agree. There are still very good RPG/COBOL experts out there, but every day, it is harder to find and hire.

 

Copper Contributor

Hi Microsoft Techs,

 

We have an old iSeries (AS/400) which we need to virtualize, ideally before Q4 this year.

Please can I ask someone to contact me, so we can get this project going.

My email address is (email address removed by moderator).

 

Regards

Michael

Community Manager

@MichaelStarrCompanies Thanks for your comment - we do not allow the sharing of private email addresses on Tech Community as per our code of conduct, but someone can feel free to private message you here on Tech Community if they like. 

Microsoft

Hello, Michael.

Thanks for reaching out.

Sure. Let's have a call to review the different options we have for AS/400 customers to migrate and modernize their applications in Azure.

Regards.

Copper Contributor

Hi @ricardogalvan 

Are you able to contact me via Teams, My availability this week is :

May 24, all day. 9:30 EST to 5:30 EST

May 25, 9:30 EST to 1:00pm EST

I also have plenty of availability next week.

 

Please let me know how best to proceed?

 

Regards

Michael

Copper Contributor

I wanted to check if someone has tried the code modernization using the above approach or a large RPG source code to see if the results were worthwhile. Exploring different options for migration of existing RPG code into c# for ease of maintenance in the long run using a larger pool of developers.

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