Question

You are scheduling a batch workload that must land only on nodes located in either the 'us-east-1a' or 'us-east-1b' zones, but must NOT run on nodes labeled 'disktype=hdd'. You write a Pod spec with a single requiredDuringSchedulingIgnoredDuringExecution nodeSelectorTerm containing two matchExpressions: one with key 'topology.kubernetes.io/zone', operator 'In', values ['us-east-1a','us-east-1b'], and one with key 'disktype', operator 'NotIn', values ['hdd']. The Pod schedules onto a node in us-east-1a that has 'disktype=ssd'. A node in us-east-1a labeled 'disktype=hdd' is available but the Pod avoids it. Which statement correctly explains the matching behavior?

Accepted Answer

Multiple matchExpressions inside a single nodeSelectorTerm are ANDed, so a node must satisfy both the zone 'In' condition and the disktype 'NotIn' condition.

Answer

Multiple matchExpressions inside a single nodeSelectorTerm are ORed, so a node matching either condition is eligible.

Answer

The 'NotIn' operator is invalid for required node affinity and is silently ignored during scheduling.

Answer

Node affinity only supports the 'In' operator; the disktype exclusion is actually enforced by an implicit taint on hdd nodes.