How often can a health check be performed on a Docker container?

The frequency of health checks on a Docker container is determined by the settings specified in the container's configuration. Docker allows users to define health checks in the Dockerfile or using the docker run command, where you can set parameters such as the interval for checking the container's health. This means that health checks can be performed every few seconds if desired.

The flexibility in setting the health check interval ensures that users can monitor the health of containers in real-time or near-real-time, which is particularly useful for applications that need immediate feedback regarding their operational status. This capability supports deploying and managing microservices effectively, as it allows for timely detection of issues, leading to a more resilient application architecture.

In contrast, other options suggest fixed or less frequent intervals that do not take advantage of Docker’s capability to perform health checks at any user-defined frequency, thus limiting the proactive monitoring of container health.