For years, software developers were tasked with maintaining and building monolithic applications that spanned their entire user-base.
Monolithic applications could be modular, but ultimately every moving part affects the entire application. When coders deployed new code, QA had to test the entire application to ensure stability.
Microservices changed the way applications are developed, and they make each moving part much more independent. One change to a container only affects one component of your environment.
Understanding Old-School Traditional Programming
Most of the legacy applications still on the market have a monolithic code-base. Some of them have a global presence and others are applications that power large corporations. Google’s code-base is monolithic. Every time a change is made to their algorithms, it’s deployed to production. When mistakes happen, it affects the index as a whole.
Other organizations keep their software private because it drives their business model. It’s not uncommon to have a large application powering customer service, sales, shipping, marketing, business, and finance from one code-base. When changes are made, they affect the application as a whole.
Monolithic programming can be stable, but it takes a good QA team and programmers with full understanding of the entire system. This can be problematic as businesses add new programmers to staff. New developers make changes to methods in the code base, and it’s not uncommon for them to accidentally introduce bugs in other parts of the application just from a misunderstanding with how these changes affect other business components.
Another issue with monolithic applications is that the code-base expands so much that it can be difficult to maintain. More bugs are introduced as developers are working with different parts of the application without knowing what the others are working on. The situation can turn terrible for the organization that can lose large amounts of revenue for bugs big or small.
The Introduction of Microservices
Microservices solve many of the problems associated with monolithic development. Where monolithic programming uses one core code-base, microservices separate this aspect into independent moving parts. With microservices, the application works independently of others, so changes and feature additions affect the service only and not the entire code-base spanned across several services.
Going back to the components of a business application, microservices would introduce a new architecture that would run independently of each other. Sales applications would run in one container while customer service runs in another. When developers add features to the sales application, it’s completely separated from other applications that control other business units.
Containers run each microservice, and they allow them to be fully automated during deployment. With monolithic deployments, a large application can take hours to update. The business usually has one person (or a team) deploy the application, have QA test it, and then deploy it piece-by-piece to every server. The team can install some automation software to make it easier to deploy, but it takes time to build these scripts and they must be monitored by the person deploying the application.
Even though microservice components run independently of each other, it doesn’t mean that they cannot communicate. Separating a monolithic application into independent components would be worthless to the business because each application still needs to communicate. Every sale made in a sales application must communicate with customer service to deal with customer issues and then with shipping to send the order. It also needs to communicate with a financial application to ensure that the business is paid.
Before you think that they cannot communicate, we introduce the idea of APIs. API is a general term giving to an interface that can be used to provide information to an application that then provides feedback. A Microsoft Windows operating system has an API that developers use to work with the operating system. Facebook has an API where developers can interact with Facebook activity. Salesforce is a global platform with an API that creates powerful interfaces for salespeople. All of these applications are separated from each other, but they provide APIs where developers can integrate them into their own software.
Containers are similar in that they can hold component applications using APIs to interact with each other. These applications have their own separate business logic coded into them, so the integrated outside software can only swap data instead of having its own code-base affecting the way the application runs. This is the main advantage of containers.
Automation and Docker
If you’ve looked into containers, you’ve probably seen Docker referenced. Docker is one of the leading containerization platforms on the market, and it allows developers to host applications in the cloud.
Docker has automation for deployment built into it. It works directly with GitHub, which most developers use as their code-base repository. If your business doesn’t use GitHub, it’s time to give it a try, because it handles much of the versioning and documentation needed to host open-source software and distribute it to your user-base.
In the Docker documentation, you can set up a linked GitHub account with your Docker account to automate deployments. You may wonder about the advantage of automating deployment, and it’s difficult for businesses used to monolithic coding to understand its advantages. Most think that it could be destruction to the application, but in fact, it saves time and reduces overhead during deployment days. By automating deployments to Docker, you can rapidly deploy changes to the application without relying on staff. It’s good for applications and emergency patches when bugs are found, but it’s also resourceful and convenient for a busy development team.
.NET Core and Its Support of Containers
Another advantage of containers is that de-coupled applications can be written in any language that you want. With monolithic applications, the entire code base (usually) is built in one base language. When you work in any enterprise, you’ll notice that the developers focus on one platform. Large global enterprises might have a heterogeneous environment, but they have large budgets to support integration between different platforms. For small to medium-sized businesses, it’s common to focus on one core programming language.
Several businesses rely on Windows and .NET applications. To keep up with the evolving development environments, Microsoft introduced containerized .NET applications and offer a way for VB.NET or C# programmers to rapidly deploy applications to containers.
Microsoft sees containerization as a scalable solution for its developer applications. When you work with containers, you instantiate an image (create a container) you should deploy to different host servers on different fault domains. This allows failover should one fail, which creates scalability and sustainability.
With containers, the application runs on the target operating system. This is unique from VMs where any operating system can be used on the VM regardless of the underlying physical machines. However, the host server can be a VM which means that containers can run on any operating system running on the target virtual machine.
Microsoft provides a test application that shows developers how to use containers using .NET and Docker. It’s also useful for developers tasked with migrating a monolithic application to container services.
Current Visual Studio versions and .NET core services support containerization, so setting up a development environment is as quick as installing the underlying .NET framework and Visual Studio software. Then the development team must shift its focus from one code base to a containerized image resource.
Time to Switch?
If you find that your monolithic software is buggy or getting out of hand, it might be time to consider a migration to containerized services. Since .NET supports the architecture, not much changes with the infrastructure. Only the code is changed to support the rapid deployment and separate services.