Docker Swarm vs. Kubernetes

Should you use Docker Swarm or Kubernetes?

Docker Swarm and Kubernetes are two of the most common platforms enterprises use for container orchestration. Both come with their own set of advantages and disadvantages. Neither is necessarily better or worse than the other; however, most organizations will find that one may be a more appropriate fit given their container orchestration needs. Enterprises should consider factors such as complexity, workload, scalability, installation, and even their IT staff’s experience with containers. By weighing all these variables, an organization should be able to decide whether Docker Swarm or Kubernetes best fits their needs.

What is a container?

To understand the benefits of Docker Swarm and Kubernetes for enterprises, it’s important to understand the basics of containers and container orchestration.

A container is a standalone runtime environment for an application. The container includes everything the application needs to execute: the application itself, libraries, configuration files, dependencies, resources files, and more. Applications in containers are isolated from their environment, so they’re able to run regardless of infrastructure or environment. Containers are ideal tools for IT departments managing deployments and updates across a wide range of devices and operating systems.

Container orchestration refers to the automation of management and operational logistics behind containerized workloads. A functioning container involves many moving parts, including microservices operating within their own containers. Thus, ensuring the stable and efficient operation of a container requires a strategy with a significant amount of complexity. To simplify this for IT departments, container orchestration offers tools and features that handle tasks such as provisioning, deployment, and load balancing. This is particularly important for organizations using a DevOps approach, as this balance allows for efficiencies to support DevOps speed and processes.

Container orchestration services are provided by platforms such as Docker Swarm and Kubernetes. Which one is right for your organization? Let’s take a closer look.

What is Docker Swarm?

Docker Swarm is a lightweight container orchestration tool used for management within the Docker platform. The term Docker Swarm comprises two individual terms. The first is Docker, which refers to both a set of tools used to manage a container and the actual related file format (known as Dockerfile). Swarm is a mode under the Docker protocol that’s used to unify management of Docker instances, allowing them to run together in a cluster (a swarm). This enables the management of multiple containers across multiple machines. The swarm manager oversees the health and status of the cluster, with each machine involved identified as a node. Its inherent benefits include robust availability and automated load balancing across multiple containers and nodes.

It’s important to note the difference between Docker Swarm and Docker Compose—another tool for running multicontainer Docker applications. While both involve the management of multiple containers, Docker Compose works under a single host while Docker Swarm manages containers deployed across multiple hosts.

What is Kubernetes?

Kubernetes is an open source platform built to manage clusters of containerized applications and services. With Kubernetes, organizations can configure, monitor, and automate containers and nodes, resulting in balanced resources and efficient management through automation. Kubernetes helps create order out of the chaos that stems from containerized applications running on systems. By managing resources, balancing workload demands, and coordinating scheduled and automated tasks, Kubernetes container orchestration ensures smooth operation across nodes and deployments on a large scale. Because it’s open source, Kubernetes also offers its own support ecosystem, featuring an engaged community that develops further tools and provides support.

Docker Swarm vs. Kubernetes: Which is better?

Docker Swarm and Kubernetes are both powerful container orchestration tools. The one that’s the best fit for your enterprise will depend on your needs and resources. Let’s break down the advantages and disadvantages of both.

Docker Swarm

Pros: Docker Swarm offers simpler management, is more lightweight, and is easier to install. Because of its ease of use, Docker Swarm is ideal for situations where the involved applications are simple or less resource intensive. It’s also more user friendly for those who are just learning about containers.

Cons: Because Docker Swarm is more lightweight than Kubernetes, it’s better suited for less intense applications or deployments. The trade-off is that Docker Swarm offers fewer features and lighter levels of automation, and it must be used with the Docker API.

Kubernetes

Pros: Kubernetes is a powerful container orchestration tool capable of working across every operating system. Kubernetes comes loaded with features that aren’t available in Docker Swarm, including self-healing, automatic scaling, and the ability to work with larger, more complex workloads and configurations. Kubernetes has a larger community as well, which leads to greater access to community-developed tools.

Cons: Because Kubernetes is more powerful than Docker Swarm, it also has a much steeper learning curve and a complex installation process. Because of this complexity, in some situations installing Kubernetes may end up hindering efficiency instead of promoting it.

So which is better for your organization? There’s no one-size-fits-all answer; it will depend on your organization’s needs and will require careful consideration of factors such as resources, application complexity, scalability requirements, and your staff’s experience with containers. But by weighing each of these variables, your IT staff will be able to decide whether to implement Docker Swarm or Kubernetes for your container orchestration.

To see containers in action, check out this reference architecture diagram for deploying a microservices-based application in Kubernetes connected to an autonomous database.