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OpenSRE uses MongoDB diagnostics to investigate database-related alerts — checking server health, finding slow queries, monitoring replica sets, and analyzing collection statistics.

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Prerequisites

  • MongoDB 4.0+ (4.4+ recommended)
  • Network access from the OpenSRE environment to your MongoDB instance
  • Valid credentials (if authentication is enabled)

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Setup

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Option 1: Interactive CLI

opensre integrations setup
Select MongoDB when prompted and provide your connection string and target database.

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Option 2: Environment variables

Add to your .env: 
MONGODB_CONNECTION_STRING=mongodb+srv://user:pass@cluster.example.net
MONGODB_DATABASE=production
MONGODB_AUTH_SOURCE=admin
MONGODB_TLS=true
VariableDefaultDescription
MONGODB_CONNECTION_STRING—Required. MongoDB connection URI
MONGODB_DATABASE(empty)Target database for profiler and collection stats
MONGODB_AUTH_SOURCEadminAuthentication database
MONGODB_TLStrueUse TLS for the connection

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Option 3: Persistent store

Integrations are automatically persisted to ~/.tracer/integrations.json: 
{
  "version": 1,
  "integrations": [
    {
      "id": "mongodb-prod",
      "service": "mongodb",
      "status": "active",
      "credentials": {
        "connection_string": "mongodb+srv://user:pass@cluster.example.net",
        "database": "production",
        "auth_source": "admin",
        "tls": true
      }
    }
  ]
}

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Connection string formats

# Localhost (no auth)
mongodb://localhost:27017

# Username/password
mongodb://user:password@host:27017/database?authSource=admin

# Replica set
mongodb://host1:27017,host2:27017,host3:27017/?replicaSet=rs0

# Atlas (SRV)
mongodb+srv://user:password@cluster.example.net
URL-encode special characters in credentials: @ → %40, : → %3A, # → %23

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TLS configuration

TLS is enabled by default. For custom certificates: 
MONGODB_CA_CERT=/path/to/ca.pem      # Custom CA certificate
MONGODB_TLS_INSECURE=true             # Skip validation (dev only)

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Investigation tools

When OpenSRE investigates a MongoDB-related alert, five diagnostic tools are available:

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Server status

Retrieves version, uptime, connection counts, operation counters, and memory usage. Useful for spotting high connection counts or unusual memory pressure.

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Current operations

Lists operations running longer than a configurable threshold (default 1 s). Surfaces long-running queries and lock contention.

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Replica set status

Reports member states, health, heartbeat intervals, and optime lag. Identifies unreachable members or sync delays.

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Profiler

Reads the system.profile collection to surface slow queries, collection scans, and index usage. Requires MONGODB_DATABASE to be configured and profiling enabled on the target database.
Enable profiling with db.setProfilingLevel(1) (slow queries only) or db.setProfilingLevel(2) (all queries).

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Collection statistics

Returns document count, storage size, index count, and average object size for a given collection.

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Verify

opensre integrations verify --service mongodb
Expected output: 
Service: mongodb
Status: passed
Detail: Connected to MongoDB 6.0.5; target database: production

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Troubleshooting

SymptomFix
Connection refusedVerify the host/port, check firewalls, and ensure MongoDB is running. For Atlas, whitelist the OpenSRE IP.
Authentication failedConfirm username/password and authSource. Test with mongosh first.
SSL: CERTIFICATE_VERIFY_FAILEDProvide a CA cert via MONGODB_CA_CERT or set MONGODB_TLS_INSECURE=true for dev.
Profiling is disabledRun db.setProfilingLevel(1) on the target database.
Server is not part of a replica setExpected for standalone instances — replica set tools return empty results, other tools still work.

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Security best practices

  • Use a read-only MongoDB user for monitoring — avoid admin credentials.
  • Always enable TLS in production.
  • Store connection strings in .env, never in code.
  • Rotate credentials periodically.