Microservices Architecture using Docker and Kubernetes

In the real world, when a problem or an objective seems too overwhelming, it is often recommended that we break it down into smaller tasks. Breaking down a complex problem into a set of micro-problems, so to speak, makes it a lot more manageable.

This approach makes sense in the world of software development too. As companies all over the world are going through robust digital transformation programs, applications are becoming more and more complex. In a traditional, monolithic application, the app is a single, unified unit and managing the complexities can become challenging. This can make changes difficult and affect performance.

Using a microservices architecture, an application designed as a collection of loosely coupled services, makes the overall application easier to develop, maintain, upgrade and scale.

What are Microservices?

Microservices can be viewed as a set of tasks that come together to make up the overall application. The scope of these microservices is narrow and each service is designed to perform a few small tasks well. Incoming page requests are broken down into many specialised requests and forwarded to corresponding microservices that become independent processes.

As a result of this, each microservice can be deployed whenever needed without disrupting the other services. It also enables scaling with independent monitoring, backing up, and disaster management.

Adopting the microservices approach facilitates quick and flexible deployment models, easier automated testing, and, overall, helps with building highly resilient software applications.

Amazon is a case in point. In early 2001, Amazon.com, the retail website was built on a monolithic architecture. Though it had multiple tiers with each having several components, it was tightly coupled. As a result, over time the architecture became more complex, increasing the overheads and slowing down the software development lifecycle. And while their customer base was growing by leaps and bounds, the platform was unable to scale at the same pace.

Amazon was faced with the prospect of refactoring their system from scratch and decided to transform the monolithic into a microservices-based architecture by breaking the applications up into small, manageable, independently-running, service-specific units. By creating a highly decoupled architecture, it became possible to iterate these services independently of each other. It also led to Amazon growing into the most valuable company in the world at a market cap of $941.19 billion.

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Using Docker Containers for Microservices

In a microservices architecture, the application can be made independent of the host environment by encapsulating each of them in Docker containers. It helps developers with the process of packaging applications into containers. Each container will have standardized executable components, bringing together source code and operating system libraries required to run that microservice in any environment.

These Docker containers are useful for resource allocation and sharing.

Advantages of using Docker for Microservices

Docker can be used to automate the deployment of applications as portable, self-sufficient containers on the cloud as well as on-premise environments, both Linux and Windows.

Some of the advantages of using Docker for microservices include:

• Top-notch community support
• The ability to work with microservices and therefore build cloud-native applications
• It’s more lightweight than virtual machines and therefore cost and resource-effective
• Provides uniform development and production environments
• Facilitates continuous integration and deployment
• Integrates with popular tools and services such as AWS, Microsoft Azure, Ansible, Kubernetes, Istio, and the like

Using Kubernetes for automated deployment, management and scaling of an application

Kubernetes (also known as K8s) enables the efficient sharing of computing resources across multiple processes, thereby optimising infrastructure utilisation by dynamically allocating computing resources based on demand.

As a result, it brings down the cost of computing resources and also improves productivity. It also makes the transition to microservices a lot easier by providing autonomy and freedom to the development teams and breaking down monolithic applications into independent, loosely-coupled microservices.

Since there needs to be close collaboration in infrastructure sharing, using Kubernetes provides the teams with a common framework for “describing, inspecting, and reasoning” infrastructure resource sharing and utilisation by:

• Forecasting the computing needs of all the resources
• Forecasting the impact of loading these requirements
• Carving out infrastructure partitions and dividing them between microservices
• Enforcing resource restrictions

How Docker and Kubernetes Work Together

Docker is fast becoming the default container format and includes a runtime environment called the Docker Engine and a container registry like Docker Hub or Azure Container Registry. Container registries facilitate the building and running containers on any development machine.

The complexities of working with Docker

While Docker facilitates the process of packaging and distributing contained apps, as applications scale more containers need to be deployed across multiple servers, adding complexity. This can result in the following issues:

• Coordination and scheduling of many containers becomes a challenge
• Different containers in the app need to talk to each other, and this could lead to errors
• Scaling up many container instances also results in bottlenecks

How Kubernetes fixes issues in Docker

Kubernetes, the open-source container-orchestration software, comes to the rescue here. It can help by allowing APIs to control the way the Docker containers and workloads are managed.

The containers, after being grouped into pods (which is the basic operational unit for Kubernetes), are scheduled to run on a cluster of virtual machines that are orchestrated, and the available are computed and are allocated appropriately. This allows the containers and pods to be scaled as needed and ensures the app is up and running at all times.

While Docker has a comparable orchestration technology called Docker Swarm for clustering Docker containers, it is tightly integrated into the Docker ecosystem, uses its own API, and runs on a single node. Kubernetes, on the other hand, runs across a cluster, is more extensive, and can efficiently coordinate clusters of nodes at scale.

The Benefits of using Kubernetes with Docker

Kubernetes enables load-balancing, networking, scaling, and security, across all its nodes. Its built-in isolation mechanism (like Kubernetes namespace) facilitates grouping container resources and provides access permission and staging environments.

As a result, developers can be given resource access for self-service or collaboration without disturbing the rest of the application in the development environment. By integrating DevOps practices, faster delivery of software and scalable orchestration of cloud-native applications become easier.

Some of the benefits of using Kubernetes with Docker include:

• Robust infrastructure and a highly available app even if some nodes are offline
• Improve application scalability

Merit Group’s expertise in Microservices Architecture Design and using Docker and Kubernetes

Merit Group, with more than 15 years of experience in software development, can work closely with enterprise customers as their ‘shadow teams’ to develop microservices and use Docker and Kubernetes to make them efficient and scalable. Our exceptional pool of talent, flexible resources, and cost-effective delivery model has already seen us power what lies “under the hood” of some of the world’s most trusted software applications.

Our engineering and software development teams bring deep expertise in C#, VB.NET, ASP.NET, JAVASCRIPT, JAVA, PHP, RUBY, PERL, PYTHON, NODE.JS. Some of our other strengths include clear communication, cost efficiency and quick scalability.