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Calculates eviction signals used by kubelet to trigger eviction manager
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# Calculate Eviction Signals - Current State vs Threshold: | |
# | |
# https://kubernetes.io/docs/concepts/scheduling-eviction/node-pressure-eviction/#eviction-signals | |
# https://medium.com/kubernetes-tutorials/efficient-node-out-of-resource-management-in-kubernetes-67f158da6e59 | |
# | |
NODES=($(kubectl get nodes -o jsonpath='{.items[*].metadata.name}')) | |
NODE_COUNT=${#NODES[@]} | |
while true; | |
do | |
for ((i=1; i<=${NODE_COUNT}; i++)); do | |
NODE=${NODES[$i-1]} | |
# ======= | |
# Refresh | |
# ======= | |
CURRENT_PAYLOAD=$(kubectl get --raw "/api/v1/nodes/${NODE}/proxy/stats/summary"); | |
THRESHOLD_PAYLOAD=$(kubectl get --raw "/api/v1/nodes/${NODE}/proxy/configz"); | |
# ==================== | |
# Current Calculations | |
# ==================== | |
# -- 1. Memory -- | |
MEMORY_AVAILABLE_BYTES=$(echo ${CURRENT_PAYLOAD} | jq .node.memory.availableBytes); | |
# MB | |
MEMORY_AVAILABLE_MB=$(echo "scale=2; ${MEMORY_AVAILABLE_BYTES}/1024/1024" | bc); | |
# -- 2. Nodefs capacity -- | |
NODEFS_AVAILABLE_BYTES=$(echo ${CURRENT_PAYLOAD} | jq .node.fs.availableBytes); | |
NODEFS_CAPACITY_BYTES=$(echo ${CURRENT_PAYLOAD} | jq .node.fs.capacityBytes); | |
# GB | |
NODEFS_AVAILABLE_GB=$(echo "scale=2; ${NODEFS_AVAILABLE_BYTES}/1024/1024/1024" | bc); | |
NODEFS_CAPACITY_GB=$(echo "scale=2; ${NODEFS_CAPACITY_BYTES}/1024/1024/1024" | bc); | |
# % | |
NODEFS_PERCENTAGE=$(echo "scale=2; ${NODEFS_AVAILABLE_GB}/${NODEFS_CAPACITY_GB}*100" | bc); | |
# -- 3. Nodefs Inodes -- | |
NODEFS_INODES_AVAILABLE=$(echo ${CURRENT_PAYLOAD} | jq .node.fs.inodesFree); | |
NODEFS_INODES_CAPACITY=$(echo ${CURRENT_PAYLOAD} | jq .node.fs.inodes); | |
# % | |
NODEFS_INODES_PERCENTAGE=$(echo "scale=2; ${NODEFS_INODES_AVAILABLE}/${NODEFS_INODES_CAPACITY}*100" | bc); | |
# -- 4. Imagefs capacity -- | |
IMAGEFS_AVAILABLE_BYTES=$(echo ${CURRENT_PAYLOAD} | jq .node.runtime.imageFs.availableBytes); | |
IMAGEFS_CAPACITY_BYTES=$(echo ${CURRENT_PAYLOAD} | jq .node.runtime.imageFs.capacityBytes); | |
# GB | |
IMAGEFS_AVAILABLE_GB=$(echo "scale=2; ${IMAGEFS_AVAILABLE_BYTES}/1024/1024/1024" | bc); | |
IMAGEFS_CAPACITY_GB=$(echo "scale=2; ${IMAGEFS_CAPACITY_BYTES}/1024/1024/1024" | bc); | |
# % | |
IMAGEFS_PERCENTAGE=$(echo "scale=2; ${IMAGEFS_AVAILABLE_GB}/${IMAGEFS_CAPACITY_GB}*100" | bc); | |
# -- 5. Imagefs Inodes -- | |
IMAGEFS_INODES_AVAILABLE=$(echo ${CURRENT_PAYLOAD} | jq .node.fs.inodesFree); | |
IMAGEFS_INODES_CAPACITY=$(echo ${CURRENT_PAYLOAD} | jq .node.fs.inodes); | |
# % | |
IMAGEFS_INODES_PERCENTAGE=$(echo "scale=2; ${NODEFS_INODES_AVAILABLE}/${NODEFS_INODES_CAPACITY}*100" | bc); | |
# -- 6. Pid stats -- | |
# | |
PID_MAX=$(echo ${CURRENT_PAYLOAD} | jq .node.rlimit.maxpid); | |
PID_CURR=$(echo ${CURRENT_PAYLOAD} | jq .node.rlimit.curproc); | |
PID_AVAILABLE=$(echo "scale=2; ${PID_MAX}-${PID_CURR}" | bc); | |
# ========= | |
# Threshold | |
# ========= | |
# Thresholds available differs by K8s distros | |
# -- 1. Memory -- | |
MEMORY_AVAILABLE_MB_THRESHOLD=$(echo ${THRESHOLD_PAYLOAD} | jq '.kubeletconfig.evictionHard."memory.available"' | sed 's/"//g'); | |
# -- 2. Nodefs capacity -- | |
NODEFS_AVAILABLE_PERCENTAGE_THRESHOLD=$(echo ${THRESHOLD_PAYLOAD} | jq '.kubeletconfig.evictionHard."nodefs.available"' | sed 's/"//g'); | |
# -- 3. Nodefs Inodes -- | |
NODEFS_INODES_AVAILABLE_PERCENTAGE_THRESHOLD=$(echo ${THRESHOLD_PAYLOAD} | jq '.kubeletconfig.evictionHard."nodefs.inodesFree"' | sed 's/"//g'); | |
# -- 4. Imagefs capacity -- | |
IMAGEFS_AVAILABLE_PERCENTAGE_THRESHOLD=$(echo ${THRESHOLD_PAYLOAD} | jq '.kubeletconfig.evictionHard."imagefs.available"' | sed 's/"//g'); | |
# -- 5. Imagefs Inodes -- | |
IMAGEFS_INODES_AVAILABLE_PERCENTAGE_THRESHOLD=$(echo ${THRESHOLD_PAYLOAD} | jq '.kubeletconfig.evictionHard."imagefs.inodesFree"' | sed 's/"//g'); | |
# -- 6. Pid stats -- | |
PID_AVAILABLE_PERCENTAGE_THRESHOLD=$(echo ${THRESHOLD_PAYLOAD} | jq '.kubeletconfig.evictionHard."pid.available"' | sed 's/"//g'); | |
echo | |
echo " ===================================================================== " | |
echo " Node ${i}/${NODE_COUNT}: ${NODE}" | |
echo " ===================================================================== " | |
echo " -- Current State ---------------------------------------------------- " | |
echo " --------------------------------------------------------------------- " | |
echo "1. memory.available: ${MEMORY_AVAILABLE_MB}Mi"; | |
echo "2. nodefs.available: ${NODEFS_PERCENTAGE}% [${NODEFS_AVAILABLE_GB}/${NODEFS_CAPACITY_GB}Gi]"; | |
echo "3. nodefs.inodesFree: ${NODEFS_INODES_PERCENTAGE}% [${NODEFS_INODES_AVAILABLE}/${NODEFS_INODES_CAPACITY}]"; | |
echo "4. imagefs.available: ${IMAGEFS_PERCENTAGE}% [${IMAGEFS_AVAILABLE_GB}/${IMAGEFS_CAPACITY_GB}Gi]"; | |
echo "5. imagefs.inodesFree: ${IMAGEFS_INODES_PERCENTAGE}% [${IMAGEFS_INODES_AVAILABLE}/${IMAGEFS_INODES_CAPACITY}]"; | |
echo "6. pid.available: ${PID_AVAILABLE}"; | |
echo " --------------------------------------------------------------------- " | |
echo " -- Eviction Thresholds ---------------------------------------------- " | |
echo " --------------------------------------------------------------------- " | |
echo "1. memory.available: ${MEMORY_AVAILABLE_MB_THRESHOLD}" | |
echo "2. nodefs.available: ${NODEFS_AVAILABLE_PERCENTAGE_THRESHOLD}" | |
echo "3. nodefs.inodesFree: ${NODEFS_INODES_AVAILABLE_PERCENTAGE_THRESHOLD}" | |
echo "4. imagefs.available: ${IMAGEFS_AVAILABLE_PERCENTAGE_THRESHOLD}" | |
echo "5. imagefs.inodesFree: ${IMAGEFS_INODES_AVAILABLE_PERCENTAGE_THRESHOLD}" | |
echo "6. pid.available: ${PID_AVAILABLE_PERCENTAGE_THRESHOLD}" | |
echo " --------------------------------------------------------------------- " | |
echo | |
done | |
done |
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