groups:
- name: node_exporter_alerts
  rules:
  - alert: Node down
    expr: up{job="monitoring-pi"} == 0
    for: 2m
    labels:
      severity: warning
    annotations:
      title: Node {{ $labels.instance }} is down
      description: Failed to scrape {{ $labels.job }} on {{ $labels.instance }} for more than 2 minutes. Node seems down.


  - alert: HostOutOfMemory
    expr: node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes * 100 < 10
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host out of memory (instance {{ $labels.instance }})
      description: Node memory is filling up (< 10% left)\n  VALUE = {{ $value }}

  - alert: HostMemoryUnderMemoryPressure
    expr: rate(node_vmstat_pgmajfault[1m]) > 1000
    for: 2m
    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 }}

  - alert: HostUnusualNetworkThroughputIn
    expr: sum by (instance) (rate(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 }}

  - alert: HostUnusualNetworkThroughputOut
    expr: sum by (instance) (rate(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 }}

  - alert: HostUnusualDiskReadRate
    expr: sum by (instance) (rate(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 }}

  - alert: HostUnusualDiskWriteRate
    expr: sum by (instance) (rate(node_disk_written_bytes_total[2m])) / 1024 / 1024 > 50
    for: 2m
    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 }}

  # Please add ignored mountpoints in node_exporter parameters like
  # "--collector.filesystem.ignored-mount-points=^/(sys|proc|dev|run)($|/)".
  # Same rule using "node_filesystem_free_bytes" will fire when disk fills for non-root users.
  - alert: HostOutOfDiskSpace
    expr: (node_filesystem_avail_bytes * 100) / node_filesystem_size_bytes < 10 and ON (instance, device, mountpoint) node_filesystem_readonly == 0
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host out of disk space (instance {{ $labels.instance }})
      description: Disk is almost full (< 10% left)\n  VALUE = {{ $value }}

  # Please add ignored mountpoints in node_exporter parameters like
  # "--collector.filesystem.ignored-mount-points=^/(sys|proc|dev|run)($|/)".
  # Same rule using "node_filesystem_free_bytes" will fire when disk fills for non-root users.
  - alert: HostDiskWillFillIn24Hours
    expr: (node_filesystem_avail_bytes * 100) / node_filesystem_size_bytes < 10 and ON (instance, device, mountpoint) predict_linear(node_filesystem_avail_bytes{fstype!~"tmpfs"}[1h], 24 * 3600) < 0 and ON (instance, device, mountpoint) node_filesystem_readonly == 0
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host disk will fill in 24 hours (instance {{ $labels.instance }})
      description: Filesystem is predicted to run out of space within the next 24 hours at current write rate\n  VALUE = {{ $value }}

  - alert: HostOutOfInodes
    expr: node_filesystem_files_free{mountpoint ="/rootfs"} / node_filesystem_files{mountpoint="/rootfs"} * 100 < 10 and ON (instance, device, mountpoint) node_filesystem_readonly{mountpoint="/rootfs"} == 0
    for: 2m
    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 }}

  - alert: HostInodesWillFillIn24Hours
    expr: node_filesystem_files_free{mountpoint ="/rootfs"} / node_filesystem_files{mountpoint="/rootfs"} * 100 < 10 and predict_linear(node_filesystem_files_free{mountpoint="/rootfs"}[1h], 24 * 3600) < 0 and ON (instance, device, mountpoint) node_filesystem_readonly{mountpoint="/rootfs"} == 0
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host inodes will fill in 24 hours (instance {{ $labels.instance }})
      description: Filesystem is predicted to run out of inodes within the next 24 hours at current write rate\n  VALUE = {{ $value }}

  - alert: HostUnusualDiskReadLatency
    expr: rate(node_disk_read_time_seconds_total[1m]) / rate(node_disk_reads_completed_total[1m]) > 0.1 and rate(node_disk_reads_completed_total[1m]) > 0
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host unusual disk read latency (instance {{ $labels.instance }})
      description: Disk latency is growing (read operations > 100ms)\n  VALUE = {{ $value }}

  - alert: HostUnusualDiskWriteLatency
    expr: rate(node_disk_write_time_seconds_totali{device!~"mmcblk.+"}[1m]) / rate(node_disk_writes_completed_total{device!~"mmcblk.+"}[1m]) > 0.1 and rate(node_disk_writes_completed_total{device!~"mmcblk.+"}[1m]) > 0
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host unusual disk write latency (instance {{ $labels.instance }})
      description: Disk latency is growing (write operations > 100ms)\n  VALUE = {{ $value }}

  - alert: HostHighCpuLoad
    expr: 100 - (avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[2m])) * 100) > 80
    for: 0m
    labels:
      severity: warning
    annotations:
      summary: Host high CPU load (instance {{ $labels.instance }})
      description: CPU load is > 80%\n  VALUE = {{ $value }}

  - alert: HostCpuStealNoisyNeighbor
    expr: avg by(instance) (rate(node_cpu_seconds_total{mode="steal"}[5m])) * 100 > 10
    for: 0m
    labels:
      severity: warning
    annotations:
      summary: Host CPU steal noisy neighbor (instance {{ $labels.instance }})
      description: CPU steal is > 10%. A noisy neighbor is killing VM performances or a spot instance may be out of credit.\n  VALUE = {{ $value }}

  # 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"})) > 1000
    for: 0m
    labels:
      severity: warning
    annotations:
      summary: Host context switching (instance {{ $labels.instance }})
      description: Context switching is growing on node (> 1000 / s)\n  VALUE = {{ $value }}

  - alert: HostSwapIsFillingUp
    expr: (1 - (node_memory_SwapFree_bytes / node_memory_SwapTotal_bytes)) * 100 > 80
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host swap is filling up (instance {{ $labels.instance }})
      description: Swap is filling up (>80%)\n  VALUE = {{ $value }}

  - alert: HostSystemdServiceCrashed
    expr: node_systemd_unit_state{state="failed"} == 1
    for: 0m
    labels:
      severity: warning
    annotations:
      summary: Host SystemD service crashed (instance {{ $labels.instance }})
      description: SystemD service crashed\n  VALUE = {{ $value }}

  - 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 }}

  - alert: HostNodeOvertemperatureAlarm
    expr: node_hwmon_temp_crit_alarm_celsius == 1
    for: 0m
    labels:
      severity: critical
    annotations:
      summary: Host node overtemperature alarm (instance {{ $labels.instance }})
      description: Physical node temperature alarm triggered\n  VALUE = {{ $value }}

  - alert: HostRaidArrayGotInactive
    expr: node_md_state{state="inactive"} > 0
    for: 0m
    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 }}

  - alert: HostRaidDiskFailure
    expr: node_md_disks{state="failed"} > 0
    for: 2m
    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 }}

  - alert: HostOomKillDetected
    expr: increase(node_vmstat_oom_kill[1m]) > 0
    for: 0m
    labels:
      severity: warning
    annotations:
      summary: Host OOM kill detected (instance {{ $labels.instance }})
      description: OOM kill detected\n  VALUE = {{ $value }}

  - alert: HostEdacCorrectableErrorsDetected
    expr: increase(node_edac_correctable_errors_total[1m]) > 0
    for: 0m
    labels:
      severity: info
    annotations:
      summary: Host EDAC Correctable Errors detected (instance {{ $labels.instance }})
      description: Instance has had {{ printf "%.0f" $value }} correctable memory errors reported by EDAC in the last 5 minutes.\n  VALUE = {{ $value }}

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

  - alert: HostNetworkReceiveErrors
    expr: rate(node_network_receive_errs_total[2m]) / rate(node_network_receive_packets_total[2m]) > 0.01
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host Network Receive Errors (instance {{ $labels.instance }}:{{ $labels.device }})
      description: Instance interface has encountered {{ printf "%.0f" $value }} receive errors in the last five minutes.\n  VALUE = {{ $value }}

  - alert: HostNetworkTransmitErrors
    expr: rate(node_network_transmit_errs_total[2m]) / rate(node_network_transmit_packets_total[2m]) > 0.01
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host Network Transmit Errors (instance {{ $labels.instance }}:{{ $labels.device }})
      description: Instance has encountered {{ printf "%.0f" $value }} transmit errors in the last five minutes.\n  VALUE = {{ $value }}

  - alert: HostNetworkInterfaceSaturated
    expr: (rate(node_network_receive_bytes_total{device!~"^tap.*"}[1m]) + rate(node_network_transmit_bytes_total{device!~"^tap.*"}[1m])) / node_network_speed_bytes{device!~"^tap.*"} > 0.8
    for: 1m
    labels:
      severity: warning
    annotations:
      summary: Host Network Interface Saturated (instance {{ $labels.instance }}:{{ $labels.interface }})
      description: The network interface is getting overloaded.\n  VALUE = {{ $value }}

  - alert: HostConntrackLimit
    expr: node_nf_conntrack_entries / node_nf_conntrack_entries_limit > 0.8
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: Host conntrack limit (instance {{ $labels.instance }})
      description: The number of conntrack is approching limit\n  VALUE = {{ $value }}

  - alert: HostClockSkew
    expr: (node_timex_offset_seconds > 0.05 and deriv(node_timex_offset_seconds[5m]) >= 0) or (node_timex_offset_seconds < -0.05 and deriv(node_timex_offset_seconds[5m]) <= 0)
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host clock skew (instance {{ $labels.instance }})
      description: Clock skew detected. Clock is out of sync.\n  VALUE = {{ $value }}

  - alert: HostClockNotSynchronising
    expr: min_over_time(node_timex_sync_status[1m]) == 0 and node_timex_maxerror_seconds >= 16
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: Host clock not synchronising (instance {{ $labels.instance }})
      description: Clock not synchronising.\n  VALUE = {{ $value }}