# general cluster availability

# alert if another failed member will result in an unavailable cluster
ALERT InsufficientMembers
IF count(up{job="etcd"} == 0) > (count(up{job="etcd"}) / 2 - 1)
FOR 3m
LABELS {
  severity = "critical"
}
ANNOTATIONS {
  summary = "etcd cluster insufficient members",
  description = "If one more etcd member goes down the cluster will be unavailable",
}

# etcd leader alerts
# ==================

# alert if any etcd instance has no leader
ALERT NoLeader
IF etcd_server_has_leader{job="etcd"} == 0
FOR 1m
LABELS {
  severity = "critical"
}
ANNOTATIONS {
  summary = "etcd member has no leader",
  description = "etcd member {{ $labels.instance }} has no leader",
}

# alert if there are lots of leader changes
ALERT HighNumberOfLeaderChanges
IF increase(etcd_server_leader_changes_seen_total{job="etcd"}[1h]) > 3
LABELS {
  severity = "warning"
}
ANNOTATIONS {
  summary = "a high number of leader changes within the etcd cluster are happening",
  description = "etcd instance {{ $labels.instance }} has seen {{ $value }} leader changes within the last hour",
}

# gRPC request alerts
# ===================

# alert if more than 1% of gRPC method calls have failed within the last 5 minutes
ALERT HighNumberOfFailedGRPCRequests
IF 100 * (sum by(grpc_method) (rate(etcd_grpc_requests_failed_total{job="etcd"}[5m]))
  / sum by(grpc_method) (rate(etcd_grpc_total{job="etcd"}[5m]))) > 1
FOR 10m
LABELS {
  severity = "warning"
}
ANNOTATIONS {
  summary = "a high number of gRPC requests are failing",
  description = "{{ $value }}% of requests for {{ $labels.grpc_method }} failed on etcd instance {{ $labels.instance }}",
}

# alert if more than 5% of gRPC method calls have failed within the last 5 minutes
ALERT HighNumberOfFailedGRPCRequests
IF 100 * (sum by(grpc_method) (rate(etcd_grpc_requests_failed_total{job="etcd"}[5m]))
  / sum by(grpc_method) (rate(etcd_grpc_total{job="etcd"}[5m]))) > 5
FOR 5m
LABELS {
  severity = "critical"
}
ANNOTATIONS {
  summary = "a high number of gRPC requests are failing",
  description = "{{ $value }}% of requests for {{ $labels.grpc_method }} failed on etcd instance {{ $labels.instance }}",
}

# alert if the 99th percentile of gRPC method calls take more than 150ms
ALERT GRPCRequestsSlow
IF histogram_quantile(0.99, sum(rate(grpc_server_handling_seconds_bucket{job="etcd",grpc_type="unary"}[5m])) by (grpc_service, grpc_method, le)) > 0.15
FOR 10m
LABELS {
  severity = "critical"
}
ANNOTATIONS {
  summary = "slow gRPC requests",
  description = "on etcd instance {{ $labels.instance }} gRPC requests to {{ $labels.grpc_method }} are slow",
}

# file descriptor alerts
# ======================

instance:fd_utilization = process_open_fds / process_max_fds

# alert if file descriptors are likely to exhaust within the next 4 hours
ALERT FdExhaustionClose
IF predict_linear(instance:fd_utilization[1h], 3600 * 4) > 1
FOR 10m
LABELS {
  severity = "warning"
}
ANNOTATIONS {
  summary = "file descriptors soon exhausted",
  description = "{{ $labels.job }} instance {{ $labels.instance }} will exhaust its file descriptors soon",
}

# alert if file descriptors are likely to exhaust within the next hour
ALERT FdExhaustionClose
IF predict_linear(instance:fd_utilization[10m], 3600) > 1
FOR 10m
LABELS {
  severity = "critical"
}
ANNOTATIONS {
  summary = "file descriptors soon exhausted",
  description = "{{ $labels.job }} instance {{ $labels.instance }} will exhaust its file descriptors soon",
}

# etcd member communication alerts
# ================================

# alert if 99th percentile of round trips take 150ms
ALERT EtcdMemberCommunicationSlow
IF histogram_quantile(0.99, rate(etcd_network_peer_round_trip_time_seconds_bucket[5m])) > 0.15
FOR 10m
LABELS {
  severity = "warning"
}
ANNOTATIONS {
  summary = "etcd member communication is slow",
  description = "etcd instance {{ $labels.instance }} member communication with {{ $labels.To }} is slow",
}

# etcd proposal alerts
# ====================

# alert if there are several failed proposals within an hour
ALERT HighNumberOfFailedProposals
IF increase(etcd_server_proposals_failed_total{job="etcd"}[1h]) > 5
LABELS {
  severity = "warning"
}
ANNOTATIONS {
  summary = "a high number of proposals within the etcd cluster are failing",
  description = "etcd instance {{ $labels.instance }} has seen {{ $value }} proposal failures within the last hour",
}

# etcd disk io latency alerts
# ===========================

# alert if 99th percentile of fsync durations is higher than 500ms
ALERT HighFsyncDurations
IF histogram_quantile(0.99, rate(etcd_disk_wal_fsync_duration_seconds_bucket[5m])) > 0.5
FOR 10m
LABELS {
  severity = "warning"
}
ANNOTATIONS {
  summary = "high fsync durations",
  description = "etcd instance {{ $labels.instance }} fync durations are high",
}

# alert if 99th percentile of commit durations is higher than 250ms
ALERT HighCommitDurations
IF histogram_quantile(0.99, rate(etcd_disk_backend_commit_duration_seconds_bucket[5m])) > 0.25
FOR 10m
LABELS {
  severity = "warning"
}
ANNOTATIONS {
  summary = "high commit durations",
  description = "etcd instance {{ $labels.instance }} commit durations are high",
}