diff --git a/pkg/kubelet/kubelet_node_status.go b/pkg/kubelet/kubelet_node_status.go index 0093d63ee6d..a8bc9ee18a9 100644 --- a/pkg/kubelet/kubelet_node_status.go +++ b/pkg/kubelet/kubelet_node_status.go @@ -31,6 +31,7 @@ import ( "k8s.io/kubernetes/pkg/api/resource" "k8s.io/kubernetes/pkg/api/unversioned" "k8s.io/kubernetes/pkg/cloudprovider" + "k8s.io/kubernetes/pkg/fields" "k8s.io/kubernetes/pkg/kubelet/cadvisor" "k8s.io/kubernetes/pkg/kubelet/events" "k8s.io/kubernetes/pkg/kubelet/util/sliceutils" @@ -309,13 +310,28 @@ func (kl *Kubelet) updateNodeStatus() error { // tryUpdateNodeStatus tries to update node status to master. If ReconcileCBR0 // is set, this function will also confirm that cbr0 is configured correctly. func (kl *Kubelet) tryUpdateNodeStatus() error { - node, err := kl.kubeClient.Core().Nodes().Get(string(kl.nodeName)) + // In large clusters, GET and PUT operations on Node objects coming + // from here are the majority of load on apiserver and etcd. + // To reduce the load on etcd, we are serving GET operations from + // apiserver cache (the data might be slightly delayed but it doesn't + // seem to cause more confilict - the delays are pretty small). + // TODO: Currently apiserver doesn't support serving GET operations + // from its cache. Thus we are hacking it by issuing LIST with + // field selector for the name of the node (field selectors with + // specified name are handled efficiently by apiserver). Once + // apiserver supports GET from cache, change it here. + opts := api.ListOptions{ + FieldSelector: fields.Set{"metadata.name": string(kl.nodeName)}.AsSelector(), + ResourceVersion: "0", + } + nodes, err := kl.kubeClient.Core().Nodes().List(opts) if err != nil { return fmt.Errorf("error getting node %q: %v", kl.nodeName, err) } - if node == nil { + if len(nodes.Items) != 1 { return fmt.Errorf("no node instance returned for %q", kl.nodeName) } + node := &nodes.Items[0] if kl.reconcileCIDR { kl.updatePodCIDR(node.Spec.PodCIDR)