# MongoDB monitoring with Netdata Monitors performance and health metrics of MongoDB. ## 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) - percentage 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 Netdata in the admin database. 1. Authenticate as the admin user. ``` use admin db.auth("admin", "") ``` 2. Create a user. ``` # MongoDB 2.x. db.addUser("netdata", "", true) # MongoDB 3.x or higher. db.createUser({ "user":"netdata", "pwd": "", "roles" : [ {role: 'read', db: 'admin' }, {role: 'clusterMonitor', db: 'admin'}, {role: 'read', db: 'local' } ] }) ``` ## Configuration Edit the `python.d/mongodb.conf` configuration file using `edit-config` from the Netdata [config directory](/docs/configure/nodes.md), which is typically at `/etc/netdata`. ```bash cd /etc/netdata # Replace this path with your Netdata config directory, if different sudo ./edit-config python.d/mongodb.conf ``` Sample: ```yaml 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 --- [](<>)