itamae/cookbooks/prometheus/files/etc/prometheus.d/alerts/node_exporter.yml

groups:
- name: Node
  rules:
  - alert: HostOutOfMemory
    expr: node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes * 100 < 10
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host out of memory (instance {{ $labels.instance }})"
      description: "Node memory is filling up (< 10% left)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostMemoryUnderMemoryPressure
    expr: rate(node_vmstat_pgmajfault[1m]) > 1000
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host memory under memory pressure (instance {{ $labels.instance }})"
      description: "The node is under heavy memory pressure. High rate of major page faults\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostUnusualNetworkThroughputIn
    expr: sum by (instance) (irate(node_network_receive_bytes_total[2m])) / 1024 / 1024 > 100
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host unusual network throughput in (instance {{ $labels.instance }})"
      description: "Host network interfaces are probably receiving too much data (> 100 MB/s)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostUnusualNetworkThroughputOut
    expr: sum by (instance) (irate(node_network_transmit_bytes_total[2m])) / 1024 / 1024 > 100
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host unusual network throughput out (instance {{ $labels.instance }})"
      description: "Host network interfaces are probably sending too much data (> 100 MB/s)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostUnusualDiskReadRate
    expr: sum by (instance) (irate(node_disk_read_bytes_total[2m])) / 1024 / 1024 > 50
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host unusual disk read rate (instance {{ $labels.instance }})"
      description: "Disk is probably reading too much data (> 50 MB/s)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostUnusualDiskWriteRate
    expr: sum by (instance) (irate(node_disk_written_bytes_total[2m])) / 1024 / 1024 > 50
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host unusual disk write rate (instance {{ $labels.instance }})"
      description: "Disk is probably writing too much data (> 50 MB/s)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostOutOfDiskSpace
    expr: (node_filesystem_avail_bytes{mountpoint="/rootfs"}  * 100) / node_filesystem_size_bytes{mountpoint="/rootfs"} < 10
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host out of disk space (instance {{ $labels.instance }})"
      description: "Disk is almost full (< 10% left)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostDiskWillFillIn4Hours
    expr: predict_linear(node_filesystem_free_bytes{fstype!~"tmpfs"}[1h], 4 * 3600) < 0
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host disk will fill in 4 hours (instance {{ $labels.instance }})"
      description: "Disk will fill in 4 hours at current write rate\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostOutOfInodes
    expr: node_filesystem_files_free{mountpoint ="/rootfs"} / node_filesystem_files{mountpoint ="/rootfs"} * 100 < 10
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host out of inodes (instance {{ $labels.instance }})"
      description: "Disk is almost running out of available inodes (< 10% left)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostUnusualDiskReadLatency
    expr: rate(node_disk_read_time_seconds_total[1m]) / rate(node_disk_reads_completed_total[1m]) > 100
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host unusual disk read latency (instance {{ $labels.instance }})"
      description: "Disk latency is growing (read operations > 100ms)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostUnusualDiskWriteLatency
    expr: rate(node_disk_write_time_seconds_total[1m]) / rate(node_disk_writes_completed_total[1m]) > 100
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host unusual disk write latency (instance {{ $labels.instance }})"
      description: "Disk latency is growing (write operations > 100ms)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostHighCpuLoad
    expr: 100 - (avg by(instance) (irate(node_cpu_seconds_total{mode="idle"}[5m])) * 100) > 80
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host high CPU load (instance {{ $labels.instance }})"
      description: "CPU load is > 80%\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  # 1000 context switches is an arbitrary number.
  # Alert threshold depends on nature of application.
  # Please read: https://github.com/samber/awesome-prometheus-alerts/issues/58
  - alert: HostContextSwitching
    expr: (rate(node_context_switches_total[5m])) / (count without(cpu, mode) (node_cpu_seconds_total{mode="idle"})) > 4500
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host context switching (instance {{ $labels.instance }})"
      description: "Context switching is growing on node (> 4500 / s)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostSwapIsFillingUp
    expr: (1 - (node_memory_SwapFree_bytes / node_memory_SwapTotal_bytes)) * 100 > 80
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host swap is filling up (instance {{ $labels.instance }})"
      description: "Swap is filling up (>80%)\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostSystemdServiceCrashed
    expr: node_systemd_unit_state{state="failed"} == 1
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host SystemD service crashed (instance {{ $labels.instance }})"
      description: "SystemD service crashed\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostPhysicalComponentTooHot
    expr: node_hwmon_temp_celsius > 75
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host physical component too hot (instance {{ $labels.instance }})"
      description: "Physical hardware component too hot\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostNodeOvertemperatureAlarm
    expr: node_hwmon_temp_alarm == 1
    for: 5m
    labels:
      severity: critical
    annotations:
      summary: "Host node overtemperature alarm (instance {{ $labels.instance }})"
      description: "Physical node temperature alarm triggered\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostRaidArrayGotInactive
    expr: node_md_state{state="inactive"} > 0
    for: 5m
    labels:
      severity: critical
    annotations:
      summary: "Host RAID array got inactive (instance {{ $labels.instance }})"
      description: "RAID array {{ $labels.device }} is in degraded state due to one or more disks failures. Number of spare drives is insufficient to fix issue automatically.\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostRaidDiskFailure
    expr: node_md_disks{state="fail"} > 0
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host RAID disk failure (instance {{ $labels.instance }})"
      description: "At least one device in RAID array on {{ $labels.instance }} failed. Array {{ $labels.md_device }} needs attention and possibly a disk swap\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostKernelVersionDeviations
    expr: count(sum(label_replace(node_uname_info, "kernel", "$1", "release", "([0-9]+.[0-9]+.[0-9]+).*")) by (kernel)) > 2
    for: 24h
    labels:
      severity: warning
    annotations:
      summary: "Host kernel version deviations (instance {{ $labels.instance }})"
      description: "Different kernel versions are running\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostOomKillDetected
    expr: increase(node_vmstat_oom_kill[5m]) > 0
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host OOM kill detected (instance {{ $labels.instance }})"
      description: "OOM kill detected\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  - alert: HostEdacCorrectableErrorsDetected
    expr: increase(node_edac_correctable_errors_total[5m]) > 0
    for: 5m
    labels:
      severity: info
    annotations:
      summary: "Host EDAC Correctable Errors detected (instance {{ $labels.instance }})"
      description: '{{ $labels.instance }} has had {{ printf "%.0f" $value }} correctable memory errors reported by EDAC in the last 5 minutes.\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}'

  - alert: HostEdacUncorrectableErrorsDetected
    expr: node_edac_uncorrectable_errors_total > 0
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host EDAC Uncorrectable Errors detected (instance {{ $labels.instance }})"
      description: '{{ $labels.instance }} has had {{ printf "%.0f" $value }} uncorrectable memory errors reported by EDAC in the last 5 minutes.\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}'

  - alert: HostNetworkReceiveErrors
    expr: increase(node_network_receive_errs_total[5m]) > 0
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host Network Receive Errors (instance {{ $labels.instance }})"
      description: '{{ $labels.instance }} interface {{ $labels.device }} has encountered {{ printf "%.0f" $value }} receive errors in the last five minutes.\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}'

  - alert: HostNetworkTransmitErrors
    expr: increase(node_network_transmit_errs_total[5m]) > 0
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "Host Network Transmit Errors (instance {{ $labels.instance }})"
      description: '{{ $labels.instance }} interface {{ $labels.device }} has encountered {{ printf "%.0f" $value }} transmit errors in the last five minutes.\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}'