5 Best Practices for Application Modernization

Today, every enterprise seeks high availability, performance, security, and better user experience across its mission-critical applications. DevOps teams have to be on their toes to continuously make improvements, add new features, and resolve bugs and issues across their applications. At the same time, many enterprises have a high dependence on some monolithic legacy applications that have grown to high levels of complexity over the years. Such applications rely on different legacy databases that pose multiple challenges. It is not easy to update their existing functionalities due to many dependencies and complicated architecture. Further, the costs to maintain, monitor, and scale-up such applications can also spiral out of control. Due to these and many other constraints, enterprises are forced to modernize their applications using containers and microservices. There is a huge demand for the containerization of applications across all industries. If your organization is also in the process of modernizing some or more of its applications, here are some best practices to follow:

Before you start rearchitecting your application (which can be a highly complex and time-consuming endeavor), you need to evaluate and find the right approach to modernization by weighing the potential costs, time, and effort in the entire activity. Usually, core applications are the most difficult to modernize, but also the most in need of modernization. Depending on your application, you may choose a lift and shift approach, where the whole application is bundled as a container and deployed. However, this approach has a limitation as development teams face difficulties in pushing frequent, small changes to the application. A possible workaround is to enclose the apps in an API layer which allows them to connect with other applications. However, it’s recommended that you evaluate your applications’ past usage patterns to identify modules that can be easily decoupled and containerized. You can automatically create Docker images for your on-premises applications with conversion tools like AWS App2Container. Further, services like AWS Fargate, Azure Container Instance, or Google Cloud Run can help you rapidly deploy containers on the cloud.

Refactoring is a crucial step in application modernization as it allows breaking down a legacy app into microservices, which can easily leverage cloud infrastructure via Docker or Kubernetes. However, turning a legacy app into a granular, microservices-based application is often a resource-intensive and time-consuming task. You may have to replace older databases to make the most of the cloud. Further, you may have to use new tools and APIs for performance improvement and communication between services. While the costs and efforts in refactoring of application are unavoidable, they are more than compensated by the benefits; microservices are loosely coupled and can be called or scaled up/down individually. Refactoring also increases the modularity of code, which makes its reuse, update, and maintenance easier.

Application modernization also requires careful considerations of the application’s underlying infrastructure and data storage. You might have to evaluate what parts of your application data need to be moved, how they have to be migrated, and what tests need to be performed to ensure data isn’t lost in the transition. Containers generally allow a significant advantage in terms of portability and performance isolation on shared infrastructure. However, sometimes there are stateful containers that tightly couple with a storage layer on the infrastructure. In such cases, to ensure easy access to data from any node in the cluster, you may use a network-based storage or cloud object storage on Amazon Elastic Kubernetes Service (EKS) or Azure Kubernetes Service (AKS).

Legacy apps rely on numerous patches and have multiple dependencies. While modernizing such apps, it is crucial to ensure that nothing breaks, and that application isn’t made more vulnerable than before. Integrating container image scanning with your CI/CD toolchain can allow you to add a layer of security as it can automatically run the scans and reduce potential exposure to threats. You can consider using opensource tools like Anchore and Qualys for container image vulnerability scanning.

Running apps on Kubernetes can be very costly, especially if done inefficiently. There’s a need to continuously monitor different aspects of an application with its logs, metrics, traces, performance data, and more. You need to stay on top of critical application exceptions, database errors/warnings, unusual requests, resource usage, and more to maximize cloud ROI. While every cloud service provider offers its own monitoring service, it can become complex to get granular visibility into multi-cloud costs across different teams and accounts. You need to integrate consumption data from different clouds to get a holistic view of costs along with visibility into security vulnerabilities and platform availability.

It is possible to configure opensource tools like Prometheus, Grafana/Kibana, Elastic, Fluentd, and Jaegar to create a holistic dashboard for application monitoring. However, you may also explore Gathr’s DevOps 360 solution to get a head start in your efforts towards improving observability into containerized apps and cloud environments. Check out how we helped a leading IT services and consulting provider containerize its enterprise app and automate container deployment to eventually achieve a 60% infrastructure cost reduction on AWS.