• kubectl scale --replicas=3 -f KUBERNETES_CONF_FILE_PATH
• kubectl scale --replicas=3 rs/REPLICA_SET_NAME
• Initially ReplicationController managed the replicas to maintain the specified replicas but now ReplicaSet is used instead of it.
  • ReplicaSet supports set-based selector requirements, it supports a new selector that can do selection based on filtering according a set of values.
    • e.g. “environment” either “dev” or “qa”
    • Not only based on equality, like the Replication Controller
      • e.g. “environment” == “dev”
• Using Deployments is recommend instead of directly using ReplicaSets, unless you require custom update orchestration or don’t require updates at all.

ReplicationController

• Kind: ReplicationController
• command to get the list of rc: kubectl -n NAMESPACE get rc

ReplicaSet

• Kind: ReplicaSet
• command to get the list of rc: kubectl -n NAMESPACE get rs