Taints and Tolerations

Previously, we have seen how Pods can be configured to control which node they run on. Now we will see how nodes can control which Pods can run on them using taints and tolerations.

A taint prevents the scheduling of a pod unless that Pod has a matching toleration for the Pod. Think of taint as an attribute of a node and a toleration is an attribute of a Pod. The Pod will get scheduled on the node only if the Pod's toleration matches the node's taint. The taints on a node tell the scheduler to check which Pods tolerate the taint and run only those Pods that match their toleration with the node's taint.

A taint definition contains the key, value, and effect. The key and value will match the Pod toleration definition in the Pod specification, while the effect instructs the scheduler what should be done once the node's taint matches the Pod's toleration.

The following diagram provides an overview of how the process of controlling...