This happen's once or twice a week, without apply any commands. I just receive the alert that many of pods are down.

The settings of the cluster, created at least 40 days ago:

gcloud container \
  clusters create "yourclustername" \
  --project "yourprojectname" \
  --zone "yourregion-zone" \
  --no-enable-basic-auth \
  --release-channel "regular" \
  --machine-type "e2-standard-2" \
  --image-type "COS" \
  --disk-type "pd-ssd" \
  --disk-size "20" \
  --metadata disable-legacy-endpoints=true \
  --scopes "https://www.googleapis.com/auth/devstorage.read_only","https://www.googleapis.com/auth/logging.write","https://www.googleapis.com/auth/monitoring","https://www.googleapis.com/auth/servicecontrol","https://www.googleapis.com/auth/service.management.readonly","https://www.googleapis.com/auth/trace.append" \
  --num-nodes "2" \
  --enable-stackdriver-kubernetes \
  --enable-ip-alias \
  --network "projects/yourprojectname/global/networks/yournetwork" \
  --subnetwork "projects/yourprojectname/regions/yourregion/subnetworks/yournetwork" \
  --default-max-pods-per-node "110" \
  --enable-autoscaling \
  --min-nodes "2" \
  --max-nodes "4" \
  --no-enable-master-authorized-networks \
  --addons HorizontalPodAutoscaling,HttpLoadBalancing,NodeLocalDNS,ApplicationManager \
  --enable-autoupgrade \
  --enable-autorepair \
  --max-surge-upgrade 1 \
  --max-unavailable-upgrade 0 \
  --enable-shielded-nodes

Node condition:

I delete the pods with this error and GKE creates another, off course this is not a solution, at least 4 minutes of downtime. How to solve this? Do I need something like calico or flannel even on GKE?