MongoDB check

Overview

Connect MongoDB to Datadog in order to:

• Visualize key MongoDB metrics.
• Correlate MongoDB performance with the rest of your applications.

Setup

Installation

The MongoDB check is included in the Datadog Agent package, so you don't need to install anything else on your MongoDB masters.

Configuration

Edit the mongo.d/conf.yaml file, in the conf.d/ folder at the root of your Agent's configuration directory to start collecting your MongoDB metrics and logs. See the sample mongo.yaml for all available configuration options.

Prepare MongoDB

In a mongo shell, create a read-only user for the Datadog Agent in the admin database:

# Authenticate as the admin user.
use admin
db.auth("admin", "<YOUR_MONGODB_ADMIN_PASSWORD>")

# On MongoDB 2.x, use the addUser command.
db.addUser("datadog", "<UNIQUEPASSWORD>", true)

# On MongoDB 3.x or higher, use the createUser command.
db.createUser({
  "user":"datadog",
  "pwd": "<UNIQUEPASSWORD>",
  "roles" : [
    {role: 'read', db: 'admin' },
    {role: 'clusterMonitor', db: 'admin'},
    {role: 'read', db: 'local' }
  ]
})

Metric Collection

• Add this configuration block to your mongo.d/conf.yaml file to start gathering your MongoDB Metrics. See the sample mongo.d/conf.yaml for all available configuration options:

  init_config:
  instances:
    - server: mongodb://datadog:<UNIQUEPASSWORD>@localhost:27017/admin
      additional_metrics:
        - collection       # collect metrics for each collection
        - metrics.commands
        - tcmalloc
        - top
  

  See the sample mongo.yaml for all available configuration options

• Restart the Agent to start sending MongoDB metrics to Datadog.

Log Collection

Available for Agent >6.0

• Collecting logs is disabled by default in the Datadog Agent, you need to enable it in datadog.yaml:

  logs_enabled: true
  

• Add this configuration block to your mongo.d/conf.yaml file to start collecting your MongoDB Logs:

  logs:
      - type: file
        path: /var/log/mongodb/mongodb.log
        service: mongo
        source: mongodb
  

  Change the service and path parameter values and configure them for your environment. See the sample mongo.yaml for all available configuration options

• Restart the Agent.

Learn more about log collection in the log documentation

Validation

Run the Agent's status subcommand and look for mongo under the Checks section.

Data Collected

Metrics

See metadata.csv for a list of metrics provided by this check.

See the MongoDB 3.0 Manual for more detailed descriptions of some of these metrics.

NOTE: The following metrics are NOT collected by default:

metric prefix	what to add to additional_metrics to collect it
mongodb.collection	collection
mongodb.commands	top
mongodb.getmore	top
mongodb.insert	top
mongodb.queries	top
mongodb.readLock	top
mongodb.writeLock	top
mongodb.remove	top
mongodb.total	top
mongodb.update	top
mongodb.writeLock	top
mongodb.tcmalloc	tcmalloc
mongodb.metrics.commands	metrics.commands

Events

Replication state changes:

This check emits an event each time a Mongo node has a change in its replication state.

Service Checks

mongodb.can_connect:

Returns CRITICAL if the Agent cannot connect to MongoDB to collect metrics, otherwise OK.

Troubleshooting

Need help? Contact Datadog support.

Further Reading

Read our series of blog posts about collecting metrics from MongoDB with Datadog:

• Start here if you're using the WiredTiger storage engine.
• Start here if you're using MMAPv1 storage engine.