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19 Oct
min read

Containers or Serverless: What's Best for App Development?

Learn the benefits, drawbacks, and different use cases for serverless computing and containers for app development. Need help? Zeet can be your guide.

Jack Dwyer

Platform Engineering + DevOps

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A High Level Overview

In cloud computing, choices matter. Not too long ago, virtual machines were the talk of the town. Today, two contenders, serverless computing and containers, are vying for dominance. But what are they? And more importantly, which one is right for your needs? These aren't just tech buzzwords; they represent foundational shifts in how we think about deploying and managing software. This blog seeks to demystify these concepts, breaking down their advantages, challenges, and ideal use cases. By the end, you'll have a clearer picture of both serverless and containers, empowering you to make informed decisions for your next project. Let’s dive into the heart of this debate and understand what’s best for your deployment needs.

What is Serverless Computing?

Serverless computing, often just called "serverless," is a cloud computing model that can significantly simplify the process of deploying code into production. Despite its name, serverless doesn’t mean the absence of servers. Instead, it refers to abstracting away the underlying infrastructure, letting developers focus primarily on their application code. This approach aligns well with the philosophy of cloud-native applications, which aim to leverage the full benefits of the cloud environment, promoting scalability, resilience, and flexibility.

Popular Serverless Platforms

Three of the most recognized serverless platforms are AWS Lambda, Google Cloud Run, and Azure Functions. The three platforms allow developers to write, deploy, and run their code without concerning themselves with the actual hardware or operating system on which it runs. Essentially, the cloud provider takes responsibility for the execution, maintenance, and scaling of the function.

Benefits of Serverless

Cost-Effective Pricing Models: Unlike traditional cloud models, where you reserve and pay for computing resources irrespective of usage, with serverless, you pay only for the actual compute time your application consumes. This can result in significant savings, especially for applications with fluctuating workloads.

Automatic Scalability: Serverless applications can automatically scale with the number of requests. Whether you get ten requests or ten thousand, the serverless platform adjusts in real time without any manual intervention.

Reduced Time-to-Market: With the need to manage dynamic backend infrastructure eliminated, developers can focus on writing application code, thereby reducing the time taken to push a product or feature live.

Simplified Backend and API Development: Serverless platforms often come with integrated tools and services that simplify the creation of APIs and backend services. This ease allows even smaller teams to develop robust backend services rapidly.

Potential Drawbacks

Vendor Lock-in Concerns: When you use a specific serverless platform like AWS Lambda or Azure Functions, you risk getting deeply integrated into that provider’s services and tools. This integration can make it challenging to switch to another provider in the future.

Limitations in Terms of Runtime and Programming Languages: While serverless platforms support various programming languages, they might not cater to every language or specific version. Developers must ensure that their preferred language and runtime are compatible with the serverless provider.

State Considerations (Stateless vs. Stateful): Most serverless functions are designed to be stateless, meaning they handle each request as an isolated event. While this design aids in scalability, it might pose challenges for applications requiring a maintained state across multiple sessions or transactions.

Understanding Containers

Containers, in the realm of software, are encapsulated environments where applications can run. Think of them as lightweight boxes that carry everything an application needs to run: code, runtime, system tools, system libraries, and settings. These boxes are consistent across various environments, ensuring that "it works on my machine" woes are a thing of the past.

Introduction to Docker and Container Images

Docker is a leading platform for developing, shipping and running container applications. A container image is a lightweight, standalone, and executable software package that encompasses all the necessities for running an application. With Docker, you can create these images, ensuring consistent environments from a developer's local setup to the production server.

Benefits of Containers

Flexibility with Operating Systems and Dependencies: Containers encapsulate the software environment, allowing applications to run on any machine that supports the container system, be it Linux, Windows, or macOS. This encapsulation ensures that all dependencies are met, regardless of where the container is deployed.

Microservices Architecture Compatibility: Microservices, which break applications into small, functional modules, naturally pair with containers. Each service can be containerized, allowing for scalability and management per service.

Full Control Over the Environment: Containers give developers full control over the software environment, eliminating the "it worked in the development environment" issues. Every necessary component is bundled with the application, ensuring consistency.

Use Cases Involving Legacy Applications and Large-Scale Microservices: Containers can breathe new life into legacy applications by encapsulating them in a modern, scalable, and distributable environment. For newer, large-scale microservices, containers provide the granularity needed to manage, scale, and update individual services independently.

Challenges of Containers

Need for Container Orchestration and Package Management (Introducing Kubernetes and Helm): When working with multiple containers, especially in large-scale applications, orchestration becomes essential. Kubernetes is a container orchestration platform that automates containerized applications' deployment, scaling, and management. Helm serves as a package manager for smoother deployments for Kubernetes, allowing predefined configurations and resources. However, while these tools are powerful, they introduce a learning curve.

Overheads Associated with Managing and Scaling Containers: As applications grow, the sheer number of containers can introduce complexities. Monitoring, networking, storage, and ensuring high availability can become intricate tasks requiring specialized knowledge and tools.

Containers, while promising consistent, scalable, and modular software deployments, do come with their challenges. But with a grasp of their capabilities and the potential roadblocks, one can better navigate the software deployment landscape.

Multi-Cluster Management: Managing multiple Kubernetes clusters across different environments or regions can become necessary as organizations grow. Multi-cluster management provides centralized control, improved resilience, and optimized resource allocation. However, it introduces complexities regarding configuration, network management, and consistent deployments. Tools and platforms have emerged to address these challenges, offering unified views and streamlined workflows across multiple clusters.

Key Differences and Use Cases

Both serverless and containers have solidified their positions as significant players in the software deployment landscape. While there's overlap in their capabilities, understanding their differences can offer clarity when choosing between them.

Comparing Underlying Infrastructure and Provisioning

  • Serverless: With serverless computing, the focus is on the code, not the infrastructure. The cloud provider manages server provisioning, scaling, and maintenance. The developer's main concern is the application code and its logic. At times, entire applications can run through one serverless function, which is why you’ll sometimes hear Serverless called a FaaS (Function as a Service) framework.
  • Containers: Containers do somewhat require an understanding of the underlying infrastructure. While containers encapsulate the application's environment, there's still a need to provision, manage, and maintain the VMs and the pods within them (sometimes called Nodes) that host these containers.

Serverless for Startups vs. Containers for Large-Scale Operations

  • Serverless: Startups, especially those with limited resources, can greatly benefit from serverless architectures. The pay-as-you-go model, combined with the eliminated overhead of server management, can be financially advantageous. Moreover, rapid prototyping and reduced time-to-market are critical for startups, and serverless can accelerate these processes.
  • Containers: Containers can be the better choice for large-scale operations, especially those with complex microservices architectures or specific infrastructure needs. They offer granular control over the environment and better support for multi-cloud and hybrid-cloud scenarios.

Specific Scenarios and Their Fit

  • Web Applications: Both serverless and containers can serve web applications effectively. Due to its auto-scaling capabilities, Serverless might fit websites with fluctuating traffic (e.g., event-driven sites). Containers are ideal for complex web applications requiring consistent development, staging, and production environments.
  • IoT (Internet of Things): Serverless is increasingly becoming popular for IoT backends. Given that many IoT scenarios are event-driven (e.g., a sensor sending data when a specific event occurs), the on-demand execution model of serverless fits well.
  • Backend Services: Containers provide an encapsulated environment that ensures consistency for monolithic backend services. However, a serverless approach might be more efficient and cost-effective if the backend comprises multiple smaller, independent functions.

The choice between serverless and containers isn't about which is universally better but about which is more suitable for a project's specific needs and contexts. Developers and businesses can make more informed choices by understanding their differences and aligning them with the project's requirements.

The DevOps Perspective

In the evolving world of software delivery, DevOps practices aim to unify software development (Dev) and software operations (Ops) to enhance collaboration and productivity. Both serverless and container environments have profound implications for DevOps, reshaping workflows, tools, and best practices.

Integration of DevOps Practices

  • Serverless: Integrating DevOps in a serverless environment primarily means focusing on continuous integration and continuous delivery (CI/CD) pipelines. Since infrastructure management is largely abstracted away, the emphasis shifts to automated testing, integration, and deployment of functions to serverless platforms. Monitoring and logging become crucial to ensure that serverless applications perform as expected.
  • Containers: DevOps practices encompass everything from container creation to orchestration in a containerized environment. Containers demand a comprehensive CI/CD approach, including container building, testing, staging, and deployment. Moreover, container health, scaling, and recovery are critical operational aspects to consider.

Automation, Load Balancing, and Application Deployment Considerations

  • Serverless: The cloud provider typically handles load balancing with serverless, ensuring that each function invocation is appropriately routed and handled. In the serverless context, automation often involves automating deployment pipelines and integrating serverless applications with other services or triggers.
  • Containers: Containers offer more granularity, which also means more areas to automate. This includes automating container image builds, orchestration with tools like Kubernetes, and load balancing across container instances and nodes. Load balancing in container environments can be more complex, especially when considering service discovery, traffic routing, and failover strategies.

The Role of Cloud-Native Development

Cloud-native development is about designing applications to be inherently cloud-optimized. Both serverless and containers are inherently cloud-native:

  • Serverless: Being fully managed by cloud providers, serverless applications are inherently cloud-native. They are designed to effectively leverage the cloud's elasticity, scalability, and on-demand resources.
  • Containers: Containers align with cloud-native principles by promoting modularity, scalability, and resilience. With container-based orchestration tools like Kubernetes, which was born in the cloud era, containerized applications can effectively utilize cloud resources, ensuring agility and resilience.

From a DevOps perspective, you can use serverless and containers, depending on your use-case, with this choice representing a shift towards more flexible, scalable, and resilient application development and deployment paradigms. Embracing the principles of cloud-native development ensures that applications are optimized for modern cloud environments' dynamic, distributed, and on-demand nature.

Challenges and Considerations

Several challenges and considerations emerge when navigating the realms of serverless and containers. Addressing this head-on can significantly impact the success and efficiency of your deployment strategies.

Vendor Choices and Potential Lock-ins

Prominent cloud vendors, including Amazon (with services like AWS Lambda and ECS), Azure (offering Azure Functions and Azure Kubernetes Service), and Google Cloud (providing Google Cloud Functions and GKE), offer a suite of solutions catering to both serverless and container needs. However, the more deeply you integrate with a specific vendor's tools and services, the harder it can become to migrate or use another provider. This phenomenon, termed "vendor lock-in," can limit flexibility and potentially influence cost structures unfavorably.

Open-Source Solutions to Alleviate Vendor-Specific Issues

Fortunately, the open-source community offers tools and platforms to alleviate some of these vendor lock-in concerns. For containers, Docker and Kubernetes stand out as universally recognized tools that operate across various cloud providers. In the serverless space, frameworks like OpenFaaS or Kubeless allow for serverless function deployment on Kubernetes, providing more flexibility than vendor-specific solutions.

Technical Challenges: Latency, Computing Resources, and More

  • Latency: Especially in the serverless environment, cold starts can introduce latency. When a serverless function is invoked after being idle, it might take a few extra milliseconds to start, potentially affecting user experience.
  • Computing Resources: Both serverless and container services usually have limitations concerning CPU, memory, and execution time. Understanding and optimizing for these constraints is crucial to ensure efficient application performance.
  • State Management: Stateless designs, especially prominent in serverless, can pose challenges when applications require a preserved state between invocations or transactions.

Elevate Your Cloud Journey with Zeet

As the landscape of cloud computing grows in complexity, having a reliable partner by your side can make all the difference. At Zeet, we pride ourselves on being more than just a service provider; we're your guide, collaborator, and navigator in the expansive world of serverless and container technologies.

Whether you're a startup aiming for a lean serverless infrastructure or a large-scale enterprise looking to optimize containerized workloads, Zeet's expertise and suite of solutions can be tailored to your unique requirements.

Why Partner with Zeet?

  • In-depth Expertise: Our team is consistently at the forefront of the latest trends, ensuring you're always equipped with cutting-edge solutions.
  • Flexibility: From AWS Lambda to Kubernetes, we're adept across various platforms, ensuring you're never locked into one choice.
  • Support & Collaboration: We're with you at every step, from initial strategy to deployment and scaling. Your success is our success.

Don't let the intricacies of serverless vs. containers leave you overwhelmed. Reach out to Zeet, and let's shape the future of your cloud endeavors together.

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