How to Monitor MongoDB with Prometheus and Grafana

Monitoring MongoDB is critical for maintaining database performance, availability, and reliability in production environments. Metrics such as connections, memory usage, query performance, replication lag, and disk I/O help teams detect issues before they impact applications.

In this blog, you’ll learn how to monitor MongoDB using MongoDB Exporter and Grafana, starting from installation and ending with real-time dashboards and visual insights.

What Is MongoDB Exporter and Grafana?

MongoDB

MongoDB is a NoSQL document-based database widely used for modern, scalable applications.

Prometheus

Prometheus is an open-source monitoring system that collects metrics using a pull-based model.

MongoDB Exporter

MongoDB Exporter exposes MongoDB internal metrics in Prometheus format.

Grafana

Grafana visualizes MongoDB metrics using interactive dashboards and alerts.

Why Monitor MongoDB with Grafana?

✔ Real-time database performance insights
✔ Early detection of replication lag
✔ Monitor active connections & slow queries
✔ Capacity planning & trend analysis
✔ Production-grade observability

Monitoring Architecture Overview

Data Flow

MongoDB → MongoDB Exporter → Prometheus → Grafana

System Requirements

Component	Requirement
OS	RHEL 8 / RHEL 9 / Ubuntu
MongoDB	4.x / 5.x / 6.x
RAM	Minimum 2 GB
Ports	9216, 9090, 3000
Access	MongoDB user with read privileges

Step 1: Create MongoDB Monitoring User

Login to MongoDB shell:

mongosh

Create user:

use admin
db.createUser({
  user: "exporter",
  pwd: "StrongPassword",
  roles: [
    { role: "clusterMonitor", db: "admin" },
    { role: "readAnyDatabase", db: "admin" }
  ]
})

Step 2: Install MongoDB Exporter

cd /opt
sudo wget https://github.com/percona/mongodb_exporter/releases/download/v0.40.0/mongodb_exporter-0.40.0.linux-amd64.tar.gz

Extract:

sudo tar -xvf mongodb_exporter-0.40.0.linux-amd64.tar.gz
sudo mv mongodb_exporter-0.40.0.linux-amd64 mongodb_exporter

Create MongoDB Exporter Service

sudo nano /etc/systemd/system/mongodb_exporter.service

[Unit]
Description=MongoDB Exporter
After=network.target

[Service]
User=root
ExecStart=/opt/mongodb_exporter/mongodb_exporter \
  --mongodb.uri=mongodb://exporter:StrongPassword@localhost:27017/admin

[Install]
WantedBy=multi-user.target

Start exporter:

sudo systemctl daemon-reload
sudo systemctl enable mongodb_exporter
sudo systemctl start mongodb_exporter

Verify:

curl http://localhost:9216/metrics

Step 3: Configure Prometheus to Scrape MongoDB Metrics

Edit Prometheus config:

sudo nano /opt/prometheus/prometheus.yml

Add:

  - job_name: "mongodb"
    static_configs:
      - targets: ["localhost:9216"]

Reload Prometheus:

sudo systemctl restart prometheus

Check targets:

http://<server-ip>:9090/targets

Step 4: Install and Configure Grafana

Install Grafana:

sudo dnf install -y https://dl.grafana.com/oss/release/grafana-10.2.3-1.x86_64.rpm

Start Grafana:

sudo systemctl enable grafana-server
sudo systemctl start grafana-server

Access:

http://<server-ip>:3000

Step 5: Add Prometheus Data Source in Grafana

Steps:

1. Grafana → Settings → Data Sources
2. Select Prometheus
3. URL: http://localhost:9090
4. Save & Test

Import MongoDB Grafana Dashboard

Steps:

1. Grafana → Dashboards → Import
2. Dashboard ID: 2583
3. Select Prometheus → Import

Key MongoDB Metrics You Can Monitor

✔ Active & available connections
✔ Query operations (insert, update, delete)
✔ Replication lag
✔ WiredTiger cache usage
✔ Memory & CPU consumption
✔ Disk I/O & storage growth

Production Best Practices

✔ Use a dedicated MongoDB monitoring user
✔ Enable authentication & TLS
✔ Secure exporter endpoint
✔ Monitor replica sets individually
✔ Set Grafana alerts for thresholds

Common Issues and Fixes

Issue	Solution
No metrics in Grafana	Check Prometheus targets
Exporter not starting	Verify MongoDB URI
Authentication error	Check user roles
Dashboard empty	Select correct data source

MongoDB Exporter vs Native Monitoring

Feature	MongoDB Exporter	Native Tools
Visualization	Grafana	Limited
Alerts	Yes	Limited
Custom dashboards	Yes	No
Integration	Prometheus	Standalone

Conclusion

Monitoring MongoDB with MongoDB Exporter and Grafana provides deep visibility into database performance, enabling teams to detect issues early, optimize resources, and ensure high availability.

This setup is production-ready, scalable, and ideal for modern cloud and on-prem MongoDB deployments.