From Mainframe to Microservices: Legacy Modernization Best Practices with AWS
AWS Mainframe Modernization service makes it faster and easier for customers to modernize mainframe workloads by moving them to the cloud and benefiting from the superior agility, elasticity, and cost savings of AWS.
As they described here AWS launched a mainframe migration competency in 2021.
With AWS Mainframe Modernization, customers can refactor their mainframe workloads to run on AWS by transforming mainframe-based applications into modern cloud services.
Alternatively, customers can keep their applications as written and replatform their workloads to AWS by reusing existing code with minimal changes.
A managed runtime environment built into AWS Mainframe Modernization provides the necessary compute, memory, and storage to run both refactored and replatformed applications and helps automate the details of capacity provisioning, security, load balancing, scaling, and application health monitoring.
From Mainframe to Microservices
The concept of ‘Mainframe to Microservices’ captures the essence of the entire Cloud era, as it describes the process of not only migrating applications from legacy hardware into the Cloud, but also simultaneously modernizing those applications to a Cloud Native architecture, refactoring older platforms like COBOL to target languages such as Java or C# and cloud-first relational databases like Amazon Aurora and Amazon EKS.
As a result customers can enjoy both the elastic scalability of a tier one hosting provider but also transform their development practices and software architecture to best exploit that capability, innovating faster and more effectively.
This journey is described in this AWS case study presentation from TSYS, who re-imagined and re-engineered its core payments stack, which supports some of the largest banking and retail brands.
From 13m:05s they describe their legacy mainframe estate built up over 40 years, representing hundreds of years of development, a common scenario for most large enterprise organizations, and the need to modernize that estate to take advantage of new practices and technologies such as mobile access and data lake analytics.
At 15m:05s they move on to explaining the core ‘Monolith to Microservices’ transformation this journey involves, adapting a large single mainframe code base into a distributed network of small modular cloud applications, and provide a detailed walk through of the process to achieve that journey and the AWS services used to do so.
Phil De Valance is the Principal Product Manager for the Mainframe Modernization Competency, and in this blog provides an overview of the key practices involved.
This includes highlighting the two main transformational journeys possible, i) Migration with Middleware Emulation, where the legacy application code is moved to the emulator with as few code changes as possible, and ii) Migration with Automated Refactoring, automating both the reverse engineering and forward engineering for transforming a legacy stack (such as COBOL-based) to a newer stack (such as Java-based or .Net-based).
Once migrated the applications can then be further augmented with other AWS services, such as for data analytics and enabling new digital channel access.
Speaking at Re:invent 2018 he provides a presentation of these practices and visually explains them.
From 08:30 he describes the patterns they have as a toolbox for modernizing to AWS and divides them into two main families; one of which deals with shutting down of mainframes (Short-term Migration) and the other which adds functionality to the mainframe (Augmentation).
Short-term Migration include emulator rehosting, automated refactoring and re-platforming for Linux, where the customer could benefit from the AWS services like Elastic Load Balancing, Auto Scaling, Amazon RDS Database, Amazon CloudWatch Monitoring.
From 22:38 he explores the Augmentation scenario, which includes replicating mainframe data to AWS so that services like data analytics can be applied, and new digital channel capabilities like mobile can be developed.
- Astadia – For over 30 years, Astadia has taken on some of the biggest challenges in modernization, including cloud migration, replatforming, application modernization, and managed IT services in today’s blended enterprise and cloud ecosystem.
- Micro Focus – Micro Focus Enterprise Suite is a modernization solution, enabling customers to deploy critical mainframe-based application workloads on AWS, offering significant gains in agility, elasticity, and cost efficiency. Case studies include Kmart.
- TSRI – Since 1995, TSRI has offered a truly unique, language- and industry-neutral automated legacy software modernization service for government and commercial customers worldwide. Case studies include the US Air Force, modernizing and migrating a Unisys mainframe to the AWS GovCloud, to take advantage of Cloud Native services including cybersecurity, DevOps and automated continuous integration and delivery tools.