The Dashboard: Monitoring MongoDB Performance

30 August 2025 / 2 min read

Welcome to Day 4! 🛠️

Flying a plane without instruments is suicide. Running a database without monitoring is negligence.

1. Built-in CLI Tools

These come installed with MongoDB.

`mongostat`

Shows a real-time table of database status every second.

insert/query/update/delete: Ops per second.
dirty: % of cache that needs to be written to disk (High = Bad).
qr/qw: Queue Read/Write. If > 0, your DB is overloaded!

`mongotop`

Shows which collections are taking the most time reading/writing. Great for spotting that one collection that is eating 90% of your resources.

2. MongoDB Compass Performance Tab

If you prefer UI, Compass has a “Performance” tab. It shows live graphs of:

Operations
Memory Usage
Hot Collections

3. The Professional Suite: MongoDB Atlas

If you use Atlas, you get:

Profiler: Automatically captures slow queries (>100ms) and suggests indexes.
Alerts: SMS/Email when CPU > 80% or Connections > 1000.
Charts: Visual dashboards for your business metrics (not just server metrics).

4. Third-Party Tools

Datadog / New Relic: Great if you want to see your DB metrics alongside your Node.js API metrics.
Percona Monitoring and Management (PMM): The best free, open-source tool for self-hosted instances.

🧠 Daily Challenge

Open your terminal.
Run mongostat while running your “Bulk Write” script from Week 4.
Watch the insert column spike!
Run mongotop and see your collection name appear at the top.

See you on Day 5 for the Grand Finale: A Distributed Chat App! 🎓

Next Step

Next: Mini Project Distributed Chat →