# File contains default list of alerts for VictoriaMetrics cluster.
# The alerts below are just recommendations and may require some updates
# and threshold calibration according to every specific setup.
groups:
  # Alerts group for VM cluster assumes that Grafana dashboard
  # https://grafana.com/grafana/dashboards/11176 is installed.
  # Please, update the `dashboard` annotation according to your setup.
  - name: vmcluster
    interval: 30s
    concurrency: 2
    rules:
      - alert: DiskRunsOutOfSpaceIn3Days
        expr: |
          vm_free_disk_space_bytes / ignoring(path)
          (
             (
              rate(vm_rows_added_to_storage_total[1d]) -
              ignoring(type) rate(vm_deduplicated_samples_total{type="merge"}[1d])
             )
            * scalar(
              sum(vm_data_size_bytes{type!="indexdb"}) /
              sum(vm_rows{type!="indexdb"})
             )
          ) < 3 * 24 * 3600 > 0
        for: 30m
        labels:
          severity: critical
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=113&var-instance={{ $labels.instance }}"
          summary: "Instance {{ $labels.instance }} will run out of disk space in 3 days"
          description: "Taking into account current ingestion rate, free disk space will be enough only
              for {{ $value | humanizeDuration }} on instance {{ $labels.instance }}.\n
              Consider to limit the ingestion rate, decrease retention or scale the disk space up if possible."

      - alert: DiskRunsOutOfSpace
        expr: |
          sum(vm_data_size_bytes) by(instance) /
          (
           sum(vm_free_disk_space_bytes) by(instance) +
           sum(vm_data_size_bytes) by(instance)
          ) > 0.8
        for: 30m
        labels:
          severity: critical
        annotations:
          dashboard: http://localhost:3000/d/oS7Bi_0Wz?viewPanel=110&var-instance={{ $labels.instance }}"
          summary: "Instance {{ $labels.instance }} will run out of disk space soon"
          description: "Disk utilisation on instance {{ $labels.instance }} is more than 80%.\n
            Having less than 20% of free disk space could cripple merges processes and overall performance.
            Consider to limit the ingestion rate, decrease retention or scale the disk space if possible."

      - alert: RequestErrorsToAPI
        expr: increase(vm_http_request_errors_total[5m]) > 0
        for: 15m
        labels:
          severity: warning
          show_at: dashboard
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=52&var-instance={{ $labels.instance }}"
          summary: "Too many errors served for {{ $labels.job }} path {{ $labels.path }} (instance {{ $labels.instance }})"
          description: "Requests to path {{ $labels.path }} are receiving errors.
            Please verify if clients are sending correct requests."

      - alert: RPCErrors
        expr: |
          (
           sum(increase(vm_rpc_connection_errors_total[5m])) by(job, instance)
           +
           sum(increase(vm_rpc_dial_errors_total[5m])) by(job, instance)
           +
           sum(increase(vm_rpc_handshake_errors_total[5m])) by(job, instance)
          ) > 0
        for: 15m
        labels:
          severity: warning
          show_at: dashboard
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=44&var-instance={{ $labels.instance }}"
          summary: "Too many RPC errors for {{ $labels.job }} (instance {{ $labels.instance }})"
          description: "RPC errors are interconnection errors between cluster components.\n
            Possible reasons for errors are misconfiguration, overload, network blips or unreachable components."

      - alert: ConcurrentFlushesHitTheLimit
        expr: avg_over_time(vm_concurrent_addrows_current[1m]) >= vm_concurrent_addrows_capacity
        for: 15m
        labels:
          severity: warning
          show_at: dashboard
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=133&var-instance={{ $labels.instance }}"
          summary: "vmstorage on instance {{ $labels.instance }} is constantly hitting concurrent flushes limit"
          description: "The limit of concurrent flushes on instance {{ $labels.instance }} is equal to number of CPUs.\n
            When vmstorage constantly hits the limit it means that storage is overloaded and requires more CPU."

      - alert: RowsRejectedOnIngestion
        expr: sum(rate(vm_rows_ignored_total[5m])) by (instance, reason) > 0
        for: 15m
        labels:
          severity: warning
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=135&var-instance={{ $labels.instance }}"
          summary: "Some rows are rejected on \"{{ $labels.instance }}\" on ingestion attempt"
          description: "VM is rejecting to ingest rows on \"{{ $labels.instance }}\" due to the
            following reason: \"{{ $labels.reason }}\""

      - alert: TooHighChurnRate
        expr: |
          (
             sum(rate(vm_new_timeseries_created_total[5m]))
             /
             sum(rate(vm_rows_inserted_total[5m]))
           ) > 0.1
        for: 15m
        labels:
          severity: warning
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=102"
          summary: "Churn rate is more than 10% for the last 15m"
          description: "VM constantly creates new time series.\n
            This effect is known as Churn Rate.\n
            High Churn Rate tightly connected with database performance and may
            result in unexpected OOM's or slow queries."

      - alert: TooHighChurnRate24h
        expr: |
          sum(increase(vm_new_timeseries_created_total[24h]))
          >
          (sum(vm_cache_entries{type="storage/hour_metric_ids"})* 3)
        for: 15m
        labels:
          severity: warning
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=102"
          summary: "Too high number of new series created over last 24h"
          description: "The number of created new time series over last 24h is 3x times higher than
            current number of active series.\n
            This effect is known as Churn Rate.\n
            High Churn Rate tightly connected with database performance and may
            result in unexpected OOM's or slow queries."

      - alert: TooHighSlowInsertsRate
        expr: |
          (
             sum(rate(vm_slow_row_inserts_total[5m]))
             /
             sum(rate(vm_rows_inserted_total[5m]))
           ) > 0.05
        for: 15m
        labels:
          severity: warning
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=108"
          summary: "Percentage of slow inserts is more than 5% for the last 15m"
          description: "High rate of slow inserts may be a sign of resource exhaustion
            for the current load. It is likely more RAM is needed for optimal handling of the current number of active time series."

      - alert: ProcessNearFDLimits
        expr: (process_max_fds - process_open_fds) < 100
        for: 5m
        labels:
          severity: critical
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=117&var-instance={{ $labels.instance }}"
          summary: "Number of free file descriptors is less than 100 for \"{{ $labels.job }}\"(\"{{ $labels.instance }}\") for the last 5m"
          description: "Exhausting OS file descriptors limit can cause severe degradation of the process.
          Consider to increase the limit as fast as possible."

      - alert: LabelsLimitExceededOnIngestion
        expr: sum(increase(vm_metrics_with_dropped_labels_total[5m])) by (instance) > 0
        for: 15m
        labels:
          severity: warning
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=116&var-instance={{ $labels.instance }}"
          summary: "Metrics ingested to vminsert on {{ $labels.instance }} are exceeding labels limit"
          description: "VictoriaMetrics limits the number of labels per each metric with `-maxLabelsPerTimeseries` command-line flag.\n
           This prevents from ingesting metrics with too many labels. Please verify that `-maxLabelsPerTimeseries` is configured
           correctly or that clients which send these metrics aren't misbehaving."

      - alert: VminsertVmstorageConnectionIsSaturated
        expr: rate(vm_rpc_send_duration_seconds_total[5m]) > 0.9
        for: 15m
        labels:
          severity: warning
          show_at: dashboard
        annotations:
          dashboard: "http://localhost:3000/d/oS7Bi_0Wz?viewPanel=139&var-instance={{ $labels.instance }}"
          summary: "Connection between vminsert on {{ $labels.instance }} and vmstorage on {{ $labels.addr }} is saturated"
          description: "The connection between vminsert (instance {{ $labels.instance }}) and vmstorage (instance {{ $labels.addr }})
            is saturated by more than 90% and vminsert won't be able to keep up.\n
            This usually means that more vminsert or vmstorage nodes must be added to the cluster in order to increase
            the total number of vminsert -> vmstorage links."