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As applications, architectures, and business processes become more complex, understanding how all those moving parts are performing is absolutely critical. This blog post series is about Application Modernization and cloud migration, and how observability can help organizations can keep their products running optimally for their customers. In part one, we defined Application Modernization and explained how it became the lever for user experience. Part two is about application modernization methodologies and using Shift Left Enterprise Observability for optimizing CI/CD pipelines.
There are a number of options for modernizing applications in the cloud, depending on your immediate and long-term strategy for building and hosting applications. Some enterprises do everything in one cloud platform, but others use a hybrid model that includes cloud and on-premise, public and private cloud, multi-cloud, and many other configurations. Service providers have different models to help you manage your environment.
Choose a service model
Infrastructure as a service (IaaS) provides virtualized cloud computing resources over the internet. Platform as a service (PaaS) is where a cloud provider delivers hardware and software tools to users over the internet. Software as a service (SaaS) is where cloud provider hosts applications and makes them available to end users over the internet.
Each of the XaaS models has distinct advantages, and you can combine them with on-premise resources or spanned across multiple cloud providers. You can learn more about XaaS options in my last blog, Application Modernization Presents Challenge and Opportunity.
5 cloud application modernization options
The next consideration is the type of modernization to implement for your application(s). There are five prevalent modernization options and they are described below.
- Rehost – move applications from on-premise to a cloud IaaS without altering their architecture
- Refactor – change the application code to fit a PaaS model
- Rearchitect – modify or extend the existing application code to become cloud-native
- Rebuild – rebuild applications on PaaS, remove code for the previous platform, and rearchitect to take full advantage of cloud-native features
- Replace – replace the existing application with a commercial SaaS application, if viable. Many enterprises are moving to SaaS versions of software they previously installed on-premise without losing functionality or data.
The Application Modernization CI/CD Pipeline
No discussion of Application Modernization is complete without discussing Continuous Integration/ Continuous Delivery (CI/CD) pipeline practices that have resulted from the microservices wave of Application Modernization. Think of Application Modernization types as the ‘What” and CI/CD Pipelines as the ‘How’ for implementing modern applications. The CI/CD Pipeline also includes methods such as Agile for improving the overall speed and flow of pipeline.
Continuous Integration (CI)
CI minimizes merge conflicts and speeds up code change integration with a “little and often” approach. In CI, teams commit changes to a dedicated trunk or the master branch repository. Each master automatically triggers a build and a set of tests to be run.
Continuous Delivery (CD)
In a CD pipeline, the build moves to the next step only after it has passed all the automated tests on the current stage. If it fails a test, progress stops and relevant teams are notified. Once a fix is committed, the process starts again. To be confident the build is ready, Enterprise Observability can provide deeper insight into automated test phases and display detailed contextual information if a problem occurs at any point.
Development and deployment pipelines have been around for decades, both for on-premise development and for development in the cloud. Development and deployment pipelines combined with Application Modernization require some specific steps, outlined below.
Version control, or source control, involves tracking and managing changes to software code. Version control systems are software tools that manage changes to source code over time. As development environments have accelerated, version control helps software teams work faster and smarter.
Different teams, tools, programming languages can create application code for containerized services. The build part of the CI/CD pipeline will almost certainly use version control software, automation build tools and container platforms.
Unit tests can occur at any time to ensure functionality and integration, especially for highly distributed applications. Unit test tools provide the first round of testing. Automated profiling through Enterprise Observability can check specific code components for tiny glitches that might be harder to identify later.
Automated tests assess code in simulated production environments, testing functionality and providing developers insight into the overall integrity of the application. Enterprise Observability analyzes traces and metrics to assess specific end-to-end issues that could impact performance when released to production.
Unit tests determine whether individual units of source code are fit for use as standalone components. Automated test tools assess how code segments work together as part of a whole.
Once the code is complete and passes all the CD test phases, it’s deployed into production. Enterprise Observability provides the most comprehensive means for measuring and validating the performance and veracity of n-tier applications in production.