6. MongoDB

https://github.com/percona/mongodb_exporter

1. MongoDB Down

MongoDB instance is down

  - alert: MongodbDown
    expr: mongodb_up == 0
    for: 0m
    labels:
      severity: critical
    annotations:
      summary: MongoDB Down (instance {{ $labels.instance }})
      description: "MongoDB instance is down\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

2. MongoDB replication lag

Mongodb replication lag is more than 10s

- alert: MongodbReplicationLag
  expr: avg(mongodb_replset_member_optime_date{state="PRIMARY"}) - avg(mongodb_replset_member_optime_date{state="SECONDARY"}) > 10
  for: 5m
  labels:
    severity: error
  annotations:
    summary: "MongoDB replication lag (instance {{ $labels.instance }})"
    description: "Mongodb replication lag is more than 10s\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

3. MongoDB replication headroom

MongoDB replication headroom is <= 0

- alert: MongodbReplicationHeadroom
  expr: (avg(mongodb_replset_oplog_tail_timestamp - mongodb_replset_oplog_head_timestamp) - (avg(mongodb_replset_member_optime_date{state="PRIMARY"}) - avg(mongodb_replset_member_optime_date{state="SECONDARY"}))) <= 0
  for: 5m
  labels:
    severity: error
  annotations:
    summary: "MongoDB replication headroom (instance {{ $labels.instance }})"
    description: "MongoDB replication headroom is <= 0\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

4. MongoDB number cursors open

Too many cursors opened by MongoDB for clients (> 10k)

  - alert: MongodbNumberCursorsOpen
    expr: mongodb_mongod_metrics_cursor_open{state="total"} > 10 * 1000
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: MongoDB number cursors open (instance {{ $labels.instance }})
      description: "Too many cursors opened by MongoDB for clients (> 10k)\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

5. MongoDB cursors timeouts

Too many cursors are timing out

  - alert: MongodbCursorsTimeouts
    expr: increase(mongodb_mongod_metrics_cursor_timed_out_total[1m]) > 100
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: MongoDB cursors timeouts (instance {{ $labels.instance }})
      description: "Too many cursors are timing out\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

6. MongoDB too many connections

Too many connections (> 80%)

  - alert: MongodbTooManyConnections
    expr: avg by(instance) (rate(mongodb_connections{state="current"}[1m])) / avg by(instance) (sum (mongodb_connections) by (instance)) * 100 > 80
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: MongoDB too many connections (instance {{ $labels.instance }})
      description: "Too many connections (> 80%)\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

7. MongoDB virtual memory usage

High memory usage

  - alert: MongodbVirtualMemoryUsage
    expr: (sum(mongodb_memory{type="virtual"}) BY (instance) / sum(mongodb_memory{type="mapped"}) BY (instance)) > 3
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: MongoDB virtual memory usage (instance {{ $labels.instance }})
      description: "High memory usage\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

MongoDB : `dcu/mongodb_exporter`

1. MongoDB replication lag

Mongodb replication lag is more than 10s

  - alert: MongodbReplicationLag
    expr: avg(mongodb_replset_member_optime_date{state="PRIMARY"}) - avg(mongodb_replset_member_optime_date{state="SECONDARY"}) > 10
    for: 0m
    labels:
      severity: critical
    annotations:
      summary: MongoDB replication lag (instance {{ $labels.instance }})
      description: "Mongodb replication lag is more than 10s\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

2. MongoDB replication Status 3

MongoDB Replication set member either perform startup self-checks, or transition from completing a rollback or resync

- alert: MongodbReplicationStatus3
  expr: mongodb_replset_member_state == 3
  for: 5m
  labels:
    severity: error
  annotations:
    summary: "MongoDB replication Status 3 (instance {{ $labels.instance }})"
    description: "MongoDB Replication set member either perform startup self-checks, or transition from completing a rollback or resync\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

3. MongoDB replication Status 6

MongoDB Replication set member as seen from another member of the set, is not yet known

- alert: MongodbReplicationStatus6
  expr: mongodb_replset_member_state == 6
  for: 5m
  labels:
    severity: error
  annotations:
    summary: "MongoDB replication Status 6 (instance {{ $labels.instance }})"
    description: "MongoDB Replication set member as seen from another member of the set, is not yet known\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

4 MongoDB replication Status 8

MongoDB Replication set member as seen from another member of the set, is unreachable

- alert: MongodbReplicationStatus8
  expr: mongodb_replset_member_state == 8
  for: 5m
  labels:
    severity: error
  annotations:
    summary: "MongoDB replication Status 8 (instance {{ $labels.instance }})"
    description: "MongoDB Replication set member as seen from another member of the set, is unreachable\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

5. MongoDB replication Status 9

MongoDB Replication set member is actively performing a rollback. Data is not available for reads

- alert: MongodbReplicationStatus9
  expr: mongodb_replset_member_state == 9
  for: 5m
  labels:
    severity: error
  annotations:
    summary: "MongoDB replication Status 9 (instance {{ $labels.instance }})"
    description: "MongoDB Replication set member is actively performing a rollback. Data is not available for reads\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

14. MongoDB replication Status 10

MongoDB Replication set member was once in a replica set but was subsequently removed

- alert: MongodbReplicationStatus10
  expr: mongodb_replset_member_state == 10
  for: 5m
  labels:
    severity: error
  annotations:
    summary: "MongoDB replication Status 10 (instance {{ $labels.instance }})"
    description: "MongoDB Replication set member was once in a replica set but was subsequently removed\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

15. MongoDB number cursors open