Containers vs Microservices – Introduction
The current era of technology is driven by users who constantly seek greater value from digital services. With the convergence of smartphones and cloud computing, software has become the driving force behind various activities such as ordering food, transportation, bill payments, and entertainment. As a result, the design and implementation of software have undergone significant changes to meet the demands of users. Traditional monolithic architectures have struggled to keep up with the need for rapid scalability and experimentation.
To address these challenges, modern approaches like containers and microservices have emerged as preferred models, particularly for mobile and web applications. These innovative methods are quickly gaining popularity due to their ability to meet the evolving demands of users in a fast-paced digital landscape.
Containers and microservices are interconnected concepts that enable businesses to create and implement applications with swiftness, effectiveness, and adaptability. It is difficult to discuss one without mentioning the other, as they are often employed in conjunction. While microservices and containers are separate technologies that can be used independently, they frequently complement each other.
In this blog, we will explore both containers and microservices – the tech, highlight their main similarities and distinctions, and delve into how organizations can effectively utilize them in combination.
What are containers or Containerization?
A container is a package that encapsulates an application along with all the necessary dependencies, enabling it to be deployed consistently and effortlessly across various environments. This package encompasses the essential components such as binaries, libraries, and configuration files required to execute the application successfully. Containers streamline the deployment process by consolidating all components, effectively managing interdependencies, and mitigating any concerns arising from environmental discrepancies.
Furthermore, containers exhibit process-level isolation from both other containers and non-containerized processes operating on the server. This isolation enhances the security of containers compared to running multiple applications directly on a host server. Each container can possess distinct environmental parameters, eliminating the need for all containers to share a common configuration.
In its structural aspect, a container operates on a host operating system, resembling a virtual machine in some ways. However, it differs in that it shares the underlying OS kernel, resulting in a lightweight and swift booting process with lower memory requirements. Unlike virtual machines that rely on a hypervisor, containers are hosted on a container runtime. This distinction enables a significantly higher number of containers (typically several MB in size) to be accommodated on a single server compared to virtual machines (which are typically several GB in size).
The following illustration represents the structure of a container:
Kubernetes from Google is the most popular free and open-source container management system, while Docker is the leading commercial solution. Linux has conventionally been the preferred operating system for containers, but Windows has caught up with Microsoft’s Hyper-V containers.
What are Microservices?
Microservices are independent software components that collectively fulfill the necessary functionalities to operate an application. Each microservice is responsible for a specific and distinct aspect of the application’s functionality.
Let’s understand this using example of a few businesses using microservices in their core application architecture:
- Amazon: Amazon’s website is built using a microservices architecture. Each service is responsible for a specific task, such as handling user authentication or processing orders.
- Netflix: Netflix uses microservices to deliver its streaming service. Each service is responsible for a specific task, such as managing user profiles or processing payments.
- Spotify: Spotify uses microservices to deliver its music streaming service. Each service is responsible for a specific task, such as managing user playlists or processing payments.
- Twitter: Twitter uses microservices to power its social media platform. Each service is responsible for a specific task, such as handling user authentication or processing tweets.
- Precisely defined scope
- Strong encapsulation
- Loose coupling
- Independent deployment
- Independent scalability
As per AWS, the microservice architecture entails constructing an application with discrete components, where each component functions as a service running its own application process. These services interact through well-defined interfaces utilizing lightweight APIs.
Consider an example of an e-commerce web application illustrated below. Employing a microservice architecture approach would involve dividing the application into distinct components, such as:
- Order management service
- Product Catalog service
- Payment service
Each service would maintain its own database and communicate with other services through an API gateway. The individual development and management of each service would allow for independent scalability and customization to meet specific needs and circumstances without disrupting the overall functionality of the application.
The focus of adopting microservices has primarily been on refactoring existing monolithic applications, as opposed to constructing new applications from the ground up. While microservices offer agility and scalability advantages, they also necessitate the implementation of suitable supporting infrastructure, especially considering the challenges associated with managing numerous microservices across different teams.
To address these complexities approaches like DevOps (Development and Operations) and CI/CD (Continuous Integration and Continuous Deployment) are better suited. These methodologies ensure efficient and effective management of microservices throughout the entire lifecycle, starting from the design phase and extending through the development and deployment stages.
Microservices vs. Containers: The Comparison
“A container is an advantageous technology for resource allocation and sharing, generating enthusiasm among DevOps professionals. On the contrary, a microservice is a software design pattern that sparks excitement among developers.”
To put it concisely:
- Microservices focus on the software design aspect.
- Containers concentrate on packaging software for deployment.
Therefore, we have the flexibility to decide whether we want to use a container to host a microservice. However, to fully leverage the advantages of both, it is highly beneficial to run microservices inside containers.
Deploying an entire application on a single virtual machine (VM) carries the risk of a single point of failure, regardless of whether a microservice architecture is employed. Placing multiple microservices on a single VM means they share the same underlying infrastructure and resources. If one microservice experiences an issue or fails, it can impact the entire VM and potentially bring down all the microservices running on it. Additionally, a single VM has limited capacity for scalability, and conflicts can arise between different dependencies of microservices. Managing and maintaining multiple microservices within a single VM can also be complex, as updates and configuration changes may require downtime for the entire VM.
However, distributing the application across multiple containers using microservices maximizes the combined value by offering-
- Resilience: By leveraging microservices within containers, the application becomes more resilient as failures in one microservice or container do not disrupt the entire system.
- Scalability: Combining microservices and containers allows for seamless scalability, enabling individual services to scale independently to meet varying demands.
- Targeted Improvements: Microservices in containers enable focused improvements, allowing for enhancements to specific services without requiring changes to the entire application architecture.
By deploying microservices in separate containers, each service can run independently, isolated from others, and utilize dedicated resources. This provides better fault tolerance, scalability, and flexibility, reducing the risk of a single point of failure and enabling efficient management of the microservices ecosystem.
This approach introduces flexibility, allowing developers to write applications in their preferred programming language since containers facilitate deployment across various environments. Additionally, containers contribute to efficiency by utilizing fewer resources compared to VMs.
Furthermore, the adoption of microservices and containers brings added security benefits. Isolation and a broader attack surface reduce the impact of a security breach, such as a hacking attack, on a single microservice or container, thereby limiting the overall damage.
Limitations with Microservices and Containers
The limitations associated with containers and microservices are primarily related to management complexities, particularly when dealing with large-scale distributed deployments. This entails challenges in deploying, monitoring, and managing containers and microservices in such environments, necessitating specialized tools capable of supporting orchestration and ensuring consistent deployment.
Additional challenges include:
- Complexity arising from managing microservices written in diverse programming languages.
- Costs incurred from network resource usage due to remote calls across multiple services.
- The challenges associated with investigating root causes or auditing systems arise when managing log information across distributed services, necessitating the utilization of log aggregators.
To address these challenges, careful consideration, appropriate tooling, and expertise in managing containerized microservice architectures are crucial.
What does the future hold for Containers and Microservices?
The future of containers and microservices appears promising, with ongoing advancements and increased adoption in the software development and deployment landscape. Here are some key trends and possibilities for their future:
- Continued Growth: The popularity and adoption of containers and microservices are expected to grow as more organizations recognize the benefits they offer in terms of scalability, flexibility, and agility in software development and deployment.
- Improved Tooling and Infrastructure: The ecosystem around containers and microservices will continue to evolve, providing enhanced tooling, management platforms, and infrastructure support. This includes the development of container orchestration systems like Kubernetes and improved container runtime environments.
- Integration with Cloud-native Technologies: Containers and microservices align well with cloud-native technologies, such as serverless computing and edge computing. The integration of these technologies can enable even more efficient and scalable application development and deployment.
- Increased Standardization and Interoperability: Efforts to establish standards and improve interoperability between containerization platforms and microservice frameworks will likely gain momentum. This will simplify the adoption and integration of containers and microservices across different environments and providers.
- Security and Governance Enhancements: As the adoption of containers and microservices increases, so does the focus on enhancing security and governance practices around them. This includes advancements in container security measures, authentication, access controls, and compliance frameworks.
- Fusion with Emerging Technologies: Containers and microservices will likely integrate with emerging technologies like artificial intelligence (AI), machine learning (ML), and blockchain. This fusion can unlock new possibilities for building intelligent, decentralized, and autonomous applications.
In conclusion, containers offer an ideal balance between security, performance, and management for enterprises deploying microservices. While there are scenarios where deploying microservices without containers may be preferable, such as strict isolation requirements or different OS environments, containers remain a versatile solution. It’s worth noting that containers can host not only microservices but also monolithic applications. Overall, leveraging containers for microservice deployment enables enterprises to achieve agility, scalability, and streamlined application management.
Contact us or schedule a free consultation with our team of experts at AnAr Solutions to find out the potential benefits for your business.