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mongodb

Module monitor mongodb performance and health metrics

Requirements: * python-pymongo package v2.4+.

You need to install it manually.

Number of charts depends on mongodb version, storage engine and other features (replication):

  1. Read requests: * query * getmore (operation the cursor executes to get additional data from query)

  2. Write requests: * insert * delete * update

  3. Active clients: * readers (number of clients with read operations in progress or queued) * writers (number of clients with write operations in progress or queued)

  4. Journal transactions: * commits (count of transactions that have been written to the journal)

  5. Data written to the journal: * volume (volume of data)

  6. Background flush (MMAPv1): * average ms (average time taken by flushes to execute) * last ms (time taken by the last flush)

  7. Read tickets (WiredTiger): * in use (number of read tickets in use) * available (number of available read tickets remaining)

  8. Write tickets (WiredTiger): * in use (number of write tickets in use) * available (number of available write tickets remaining)

  9. Cursors: * opened (number of cursors currently opened by MongoDB for clients) * timedOut (number of cursors that have timed) * noTimeout (number of open cursors with timeout disabled)

  10. Connections: * connected (number of clients currently connected to the database server) * unused (number of unused connections available for new clients)

  11. Memory usage metrics: * virtual * resident (amount of memory used by the database process) * mapped * non mapped

  12. Page faults: * page faults (number of times MongoDB had to request from disk)

  13. Cache metrics (WiredTiger): * percentage of bytes currently in the cache (amount of space taken by cached data) * percantage of tracked dirty bytes in the cache (amount of space taken by dirty data)

  14. Pages evicted from cache (WiredTiger): * modified * unmodified

  15. Queued requests: * readers (number of read request currently queued) * writers (number of write request currently queued)

  16. Errors: * msg (number of message assertions raised) * warning (number of warning assertions raised) * regular (number of regular assertions raised) * user (number of assertions corresponding to errors generated by users)

  17. Storage metrics (one chart for every database) * dataSize (size of all documents + padding in the database) * indexSize (size of all indexes in the database) * storageSize (size of all extents in the database)

  18. Documents in the database (one chart for all databases) * documents (number of objects in the database among all the collections)

  19. tcmalloc metrics * central cache free * current total thread cache * pageheap free * pageheap unmapped * thread cache free * transfer cache free * heap size

  20. Commands total/failed rate * count * createIndex * delete * eval * findAndModify * insert

  21. Locks metrics (acquireCount metrics - number of times the lock was acquired in the specified mode) * Global lock * Database lock * Collection lock * Metadata lock * oplog lock

  22. Replica set members state * state

  23. Oplog window * window (interval of time between the oldest and the latest entries in the oplog)

  24. Replication lag * member (time when last entry from the oplog was applied for every member)

  25. Replication set member heartbeat latency * member (time when last heartbeat was received from replica set member)

prerequisite

Create a read-only user for the netdata in the admin database.

  1. Authenticate as the admin user.
use admin
db.auth("admin", "<MONGODB_ADMIN_PASSWORD>")
  1. Create a user.
# MongoDB 2.x.
db.addUser("netdata", "<UNIQUE_PASSWORD>", true)

# MongoDB 3.x or higher.
db.createUser({
  "user":"netdata",
  "pwd": "<UNIQUE_PASSWORD>",
  "roles" : [
    {role: 'read', db: 'admin' },
    {role: 'clusterMonitor', db: 'admin'},
    {role: 'read', db: 'local' }
  ]
})

configuration

Sample:

local:
    name : 'local'
    authdb: 'admin'
    host : '127.0.0.1'
    port : 27017
    user : 'netdata'
    pass : 'netdata'

If no configuration is given, module will attempt to connect to mongodb daemon on 127.0.0.1:27017 address