The key differences between Kubernetes and Docker Swarm

The orchestration war between Kubernetes and Docker Swarm appears to be over. Back in October, Docker announced that its Enterprise Edition could be integrated with Kubernetes. This move was widely seen as the Docker team conceding to Kubernetes dominance as an orchestration tool. But Docker Swarm nevertheless remains popular; it doesn't look like it's about to fall off the face of the earth. So what is the difference between Kubernetes and Docker Swarm? And why should you choose one over the other? 

To start with it's worth saying that both container orchestration tools have a lot in common. Both let you run a cluster of containers, allowing you to increase the scale of your container deployments significantly without cloning yourself to mess about with the Docker CLI (although as you'll see, you could argue that one is more suited to scalability than the other). Ultimately, you'll need to view the various features and key differences between Docker Swarm and Kubernetes in terms of what you want to achieve. Do you want to get up and running quickly? Are you looking to deploy containers on a huge scale?

Here's a brief but useful comparison of Kubernetes and Docker Swarm. It should help you decide which container orchestration tool you should be using.

Docker Swarm is easier to use than Kubernetes

One of the main reasons you’d choose Docker Swarm over Kubernetes is that it has a much more straightforward learning curve. As popular as it is, Kubernetes is regarded by many developers as complex. Many people complain that it is difficult to configure. Docker Swarm, meanwhile, is actually pretty simple. It’s much more accessible for less experienced programmers. And if you need a container orchestration solution now, simplicity is likely going to be an important factor in your decision making.

...But Docker Swarm isn't as customizable

Although ease of use is definitely one thing Docker Swarm has over Kubernetes, it also means there's less you can actually do with it. Yes, it gets you up and running, but if you want to do something a little different, you can't. You can configure Kubernetes in a much more tailored way than Docker Swarm. That means that while the learning curve is steeper, the possibilities and opportunities open to you will be far greater.

Kubernetes gives you auto-scaling - Docker Swarm doesn't

When it comes to scalability it’s a close race. Both tools are able to run around 30,000 containers on 1,000 nodes, which is impressive. However, when it comes to auto-scaling, Kubernetes wins because Docker doesn’t offer that functionality out of the box.

Monitoring container deployments is easier with Kubernetes

This is where Kubernetes has the edge. It has in-built monitoring and logging solutions. With Docker Swarm you’ll have to use third-party applications. That isn’t necessarily a huge problem, but it does make life ever so slightly more difficult. Whether or not it makes life more difficult to outweigh the steeper Kubernetes learning curve however is another matter…

Is Kubernetes or Docker Swarm better?

Clearly, Kubernetes is a more advanced tool than Docker Swarm. That's one of the reasons why the Docker team backed down and opened up their enterprise tool for integration with Kubernetes. Kubernetes is simply the software that's defining container orchestration. And that's fine - Docker has cemented its position within the stack of technologies that support software automation and deployment. It's time to let someone else take on the challenge of orchestration

But although Kubernetes is the more 'advanced' tool, that doesn't mean you should overlook Docker Swarm. If you want to begin deploying container clusters, without the need for specific configurations, then don't allow yourself to be seduced by something shinier, something ostensibly more popular. As with everything else in software development, understand and define what job needs to be done - then choose the right tool for the job.