OpenShift 3.11 xtables lock errors and slow iptables updates by kube-proxy.

Issue

• Having network problems, when running iptables commands xtables lock errors are seen.

• Builds are failing with the below error:

  atomic-openshift-node[10569] kubelet_pods.go:1121] Failed killing the pod "myapp-deploy": failed to "KillPodSandbox" for "xxxx" with KillPodSandboxError: "rpc error: code = Unknown desc = NetworkPlugin cni failed to teardown pod \"myapp-deploy\" network: CNI request failed with status 400: 'Failed to execute iptables-restore: exit status 4 (Another app is currently holding the xtables lock. Perhaps you want to use the -w option?\n)\n'"
  

• After idling my deployments in OpenShift xtables lock errors are seen and service fail with "no route to host".

• The SDN pods have a high CPU utilization.