Step 01 · Informer stream
New pod? It arrives as a watch event.
kube-apiserver
watch cache
GET /api/v1/pods?watch=true
{"type":"ADDED","object":{"kind":"Pod","spec":{"nodeName":""}}}
kube-scheduler
SharedInformer
A SharedIndexInformer holds an open HTTP/2 stream. etcd revisions stream into the API server's watch cache, which fans them out. Pods with empty spec.nodeName trigger the scheduler's AddFunc handler.
pkg/scheduler/eventhandlers.goHTTP/2 · chunked
Step 01 · kube-apiserver
Scheduler watches the API server, not polls it