- snapshot equivalence cache generation numbers before snapshotting the
scheduler cache
- skip update when generation does not match live generation
- keep the node and increment its generation to invalidate it instead of
deletion
- use predicates order ID as key to improve performance
This adds counters to equiv. cache reads & writes. Reads are labeled by
hit/miss, while writes are labeled to indicate whether the write was
discarded.
This will give us visibility into,
- hit rate of cache reads
- ratio of reads to writes
- rate of discarded writes
This moves the equivalence cache implementation out of the 'core'
package and into k8s.io/kubernetes/pkg/scheduler/core/equivalence.
Separating the equiv. cache from the genericScheduler implementation
make their interaction points easier to follow, and prevents us from
accidentally accessing unexported fields.
