scheduling.md

Scheduling

Labels and Selectors

• Labels are simple key value pairs that you can assign to resources

"environment" : "dev", "environment" : "qa", "environment" : "production"

"tier" : "frontend", "tier" : "backend", "tier" : "cache"

"partition" : "customerA", "partition" : "customerB"

• Labels classify things

• Selectors allow you to use the labels to filter things

  • Based on equality

    environment = production
    tier != frontend
  

  • Set based

    environment in (production, qa)
    tier notin (frontend, backend)
    partition
    !partition
  

Scheduling Decisions

Node Selection

• Attach a label to a node

• Define a nodeSelector for the pod!

Affinity

Three "levels" of affinities!

• Preferred during scheduling ignored during execution

• Required while scheduling and but ignore during execution

• Required for scheduling and also during execution

Node affinity

• A pod can be defined to have affinity for certain nodes

Pod Affinity

• Schedule pods together

Pod Anti-Affinity

• These pods hate each other

Taints & Tolerations