The requiredDuringSchedulingIgnoredDuringExecution field in a Node Affinity rule specifies hard constraints for scheduling Pods onto nodes. This means that the scheduler will only place the Pod on nodes that meet the specified criteria defined in the Node Affinity rule.
Here's a breakdown of its behavior:
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Required During Scheduling: The Pod can only be scheduled on nodes that match the specified node labels. If no suitable nodes are available, the Pod will not be scheduled.
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Ignored During Execution: Once the Pod is running, if the node's labels change and no longer match the affinity rules, the Pod will continue to run on that node. The affinity rule does not affect the Pod's execution after it has been scheduled.
This allows for flexibility in managing Pods while ensuring they are initially placed on the correct nodes based on the defined criteria.
