Once upon a time, monitoring Docker containers was a tough job because few tools were good at container monitoring. That has now changed. The list of container-native monitoring tools has grown to meet the needs of organizations that have adopted Docker or other container platforms.
If you take a look at this roundup of container monitoring tools that Rancher published in 2015, you’ll notice that almost all of them are either open-source tools like CAdvisor and Prometheus that provide only basic monitoring functionality for containers, or commercial tools like Scout that no longer cater to container users. In 2015, there were few good, dedicated solutions available for monitoring containerized applications.
That’s not surprising. Container monitoring is difficult for two main reasons:
- Container platforms themselves offer only very basic monitoring functionality. You can run commands like docker stats to get few metrics about a container, but this approach doesn’t suffice for production monitoring. Nor do orchestrators like Kubernetes provide monitoring solutions. They are designed to provision infrastructure, not monitor it.
- Traditional Application Performance Monitoring (APM) tools don’t work well with containers because they are not designed to support the architecture of a containerized environment. They have difficulty peering inside containers and understanding the complex service dependencies that exist within a containerized application.
This is why it took some time for robust container APM solutions to develop.
The Commercial Container Monitoring Ecosystem Grows
Today, the list of container-native monitoring tools is much longer than it was in 2015. It includes commercial offerings such as:
- Sysdig. One of the first companies to invest in container monitoring, Sysdig offers an alerting and monitoring platform for containers that is based on open-source code.
- Datadog. Datadog is an all-purpose APM vendor, but it made early investments in Docker monitoring and continues to be an important vendor in that market.
- AppDynamics. The company has offered a Docker monitoring solution since 2015, but it has not traditionally focused heavily on the container market. That changed recently, when AppDynamics released important updates to its container monitoring platform, signaling an interest in catering to container users more extensively.
- Instana. A new APM vendor with a focus on microservices, making containers central to the company’s focus.
Curiously, open-source projects have lagged behind commercial vendors in developing container-native monitoring tools. You can still use CAdvisor or Prometheus for Docker monitoring, but their functionality in that regard has not evolved as quickly as the commercial options have.
It’s also worth noting that almost all the container APM tools on the market today focus on Docker specifically. If you use an alternative container framework, they may or may not work well for you.
But at least you have a lot more container monitoring options today than you did in 2015.