# File contains default list of alerts for various VM components.
# The following alerts are recommended for use for any VM installation.
# The alerts below are just recommendations and may require some updates
# and threshold calibration according to every specific setup.
groups:
  - name: vm-health
    # note the `job` filter and update accordingly to your setup
    rules:
      - alert: TooManyRestarts
        expr: changes(process_start_time_seconds{job=~".*(victoriametrics|vmselect|vminsert|vmstorage|vmagent|vmalert|vmsingle|vmalertmanager|vmauth).*"}[15m]) > 2
        labels:
          severity: critical
        annotations:
          summary: "{{ $labels.job }} too many restarts (instance {{ $labels.instance }})"
          description: >
            Job {{ $labels.job }} (instance {{ $labels.instance }}) has restarted more than twice in the last 15 minutes.
            It might be crashlooping.

      - alert: ServiceDown
        expr: up{job=~".*(victoriametrics|vmselect|vminsert|vmstorage|vmagent|vmalert|vmsingle|vmalertmanager|vmauth).*"} == 0
        for: 2m
        labels:
          severity: critical
        annotations:
          summary: "Service {{ $labels.job }} is down on {{ $labels.instance }}"
          description: "{{ $labels.instance }} of job {{ $labels.job }} has been down for more than 2 minutes."

      - alert: ProcessNearFDLimits
        expr: (process_max_fds - process_open_fds) < 100
        for: 5m
        labels:
          severity: critical
        annotations:
          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: TooHighMemoryUsage
        expr: (min_over_time(process_resident_memory_anon_bytes[10m]) / vm_available_memory_bytes) > 0.8
        for: 5m
        labels:
          severity: critical
        annotations:
          summary: "It is more than 80% of memory used by \"{{ $labels.job }}\"(\"{{ $labels.instance }}\")"
          description: |
            Too high memory usage may result into multiple issues such as OOMs or degraded performance.
            Consider to either increase available memory or decrease the load on the process.

      - alert: TooHighCPUUsage
        expr: rate(process_cpu_seconds_total[5m]) / process_cpu_cores_available > 0.9
        for: 5m
        labels:
          severity: critical
        annotations:
          summary: "More than 90% of CPU is used by \"{{ $labels.job }}\"(\"{{ $labels.instance }}\") during the last 5m"
          description: >
            Too high CPU usage may be a sign of insufficient resources and make process unstable.
            Consider to either increase available CPU resources or decrease the load on the process.

      - alert: TooHighGoroutineSchedulingLatency
        expr: histogram_quantile(0.99, sum(rate(go_sched_latencies_seconds_bucket{job=~".*(victoriametrics|vmselect|vminsert|vmstorage|vmagent|vmalert|vmsingle|vmalertmanager|vmauth).*"}[5m])) by (le, job, instance)) > 0.1
        for: 15m
        labels:
          severity: critical
        annotations:
          summary: "\"{{ $labels.job }}\"(\"{{ $labels.instance }}\") has insufficient CPU resources for >15m"
          description: >
            Go runtime is unable to schedule goroutines execution in acceptable time. This is usually a sign of
            insufficient CPU resources or CPU throttling. Verify that service has enough CPU resources. Otherwise,
            the service could work unreliably with delays in processing.

      - alert: TooManyLogs
        expr: sum(increase(vm_log_messages_total{level="error"}[5m])) without (app_version, location) > 0
        for: 15m
        labels:
          severity: warning
        annotations:
          summary: "Too many logs printed for job \"{{ $labels.job }}\" ({{ $labels.instance }})"
          description: >
            Logging rate for job \"{{ $labels.job }}\" ({{ $labels.instance }}) is {{ $value }} for last 15m.
            Worth to check logs for specific error messages.

      - alert: TooManyTSIDMisses
        expr: increase(vm_missing_tsids_for_metric_id_total[5m]) > 0
        for: 15m
        labels:
          severity: critical
        annotations:
          summary: "Unexpected TSID misses for job \"{{ $labels.job }}\" ({{ $labels.instance }}) for the last 15 minutes"
          description: |
            Unexpected TSID misses for \"{{ $labels.job }}\" ({{ $labels.instance }}) for the last 15 minutes.
            If this happens after unclean shutdown of VictoriaMetrics process (via \"kill -9\", OOM or power off),
            then this is OK - the alert must go away in a few minutes after the restart.
            Otherwise this may point to the corruption of index data.

      - alert: ConcurrentInsertsHitTheLimit
        expr: avg_over_time(vm_concurrent_insert_current[1m]) >= vm_concurrent_insert_capacity
        for: 15m
        labels:
          severity: warning
        annotations:
          summary: "{{ $labels.job }} on instance {{ $labels.instance }} is constantly hitting concurrent inserts limit"
          description: | 
            The limit of concurrent inserts on instance {{ $labels.instance }} depends on the number of CPUs.
            Usually, when component constantly hits the limit it is likely the component is overloaded and requires more CPU.
            In some cases for components like vmagent or vminsert the alert might trigger if there are too many clients
            making write attempts. If vmagent's or vminsert's CPU usage and network saturation are at normal level, then 
            it might be worth adjusting `-maxConcurrentInserts` cmd-line flag.

      - alert: IndexDBRecordsDrop
        expr: increase(vm_indexdb_items_dropped_total[5m]) > 0
        labels:
          severity: critical
        annotations:
          summary: "IndexDB skipped registering items during data ingestion with reason={{ $labels.reason }}."
          description: | 
            VictoriaMetrics could skip registering new timeseries during ingestion if they fail the validation process. 
            For example, `reason=too_long_item` means that time series cannot exceed 64KB. Please, reduce the number 
            of labels or label values for such series. Or enforce these limits via `-maxLabelsPerTimeseries` and 
            `-maxLabelValueLen` command-line flags.

      - alert: RowsRejectedOnIngestion
        expr: rate(vm_rows_ignored_total[5m]) > 0
        for: 15m
        labels:
          severity: warning
        annotations:
          summary: "Some rows are rejected on \"{{ $labels.instance }}\" on ingestion attempt"
          description: "Ingested rows on instance \"{{ $labels.instance }}\" are rejected due to the
            following reason: \"{{ $labels.reason }}\""

      - alert: TooHighQueryLoad
        expr: increase(vm_concurrent_select_limit_timeout_total[5m]) > 0
        for: 15m
        labels:
          severity: warning
        annotations:
          summary: "Read queries fail with timeout for {{ $labels.job }} on instance {{ $labels.instance }}"
          description: |
            Instance {{ $labels.instance }} ({{ $labels.job }}) is failing to serve read queries during last 15m.
            Concurrency limit `-search.maxConcurrentRequests` was reached on this instance and extra queries were
            put into the queue for `-search.maxQueueDuration` interval. But even after waiting in the queue these queries weren't served.
            This happens if instance is overloaded with the current workload, or datasource is too slow to respond.
            Possible solutions are the following:
            * reduce the query load;
            * increase compute resources or number of replicas;
            * adjust limits `-search.maxConcurrentRequests` and `-search.maxQueueDuration`.
            See more at https://docs.victoriametrics.com/victoriametrics/troubleshooting/#slow-queries