diff --git a/docs/admin/node.md b/docs/admin/node.md index a974b27fb83..b3f51d83807 100644 --- a/docs/admin/node.md +++ b/docs/admin/node.md @@ -167,7 +167,7 @@ Node controller is a component in Kubernetes master which manages Node objects. It performs two major functions: cluster-wide node synchronization and single node life-cycle management. -Node controller has a sync loop that creates/deletes Nodes from Kubernetes +Node controller has a sync loop that deletes Nodes from Kubernetes based on all matching VM instances listed from the cloud provider. The sync period can be controlled via flag `--node-sync-period`. If a new VM instance gets created, Node Controller creates a representation for it. If an existing @@ -178,6 +178,12 @@ join a node to a Kubernetes cluster, you as an admin need to make sure proper se running in the node. In the future, we plan to automatically provision some node services. +In general, node controller is responsible for updating the NodeReady condition of node +status to ConditionUnknown when a node becomes unreachable (e.g. due to the node being down), +and then later evicting all the pods from the node (using graceful termination) if the node +continues to be unreachable. (The current timeouts for those are 40s and 5m, respectively.) +It also allocates CIDR blocks to the new nodes. + ### Self-Registration of Nodes When kubelet flag `--register-node` is true (the default), the kubelet will attempt to