The master node serves as a kernel component in the Kubernetes system. Its duties include the following:
- Pushing and pulling information from etcd servers
- Acting as the portal for requests
- Assigning tasks to nodes
- Monitoring the running tasks
Three major daemons enable the master to fulfill the preceding duties; the following diagram indicates the activities of the aforementioned bullet points:
The interaction between the Kubernetes master and other components
As you can see, the master is the communicator between workers and clients. Therefore, it will be a problem if the master crashes. A multiple-master Kubernetes system is not only fault tolerant, but also workload-balanced. It would not be an issue if one of them crashed, since other masters would still handle the jobs. We call this infrastructure design high availability, abbreviated to HA. In...