1. Introduction

In this tutorial, we will focus on how to monitor and scale clusters in MongoDB Atlas, the global cloud database service for modern applications. By the end of this tutorial, you will have a good understanding of how to track your cluster's performance and adjust its resources as needed.

What you will learn:

• Monitoring your MongoDB Atlas clusters
• Scaling your MongoDB Atlas clusters

Prerequisites:

• A basic understanding of MongoDB
• A MongoDB Atlas account

2. Step-by-Step Guide

Monitoring Clusters

MongoDB Atlas provides an in-built tool to monitor your clusters. It includes charts for key metrics like CPU utilization, memory usage, and operation execution times.

To monitor your cluster:

1. Navigate to the "Clusters" section on your MongoDB Atlas dashboard.
2. Click on the "Metrics" tab.

Here, you can view a variety of charts that track different metrics over time.

Scaling Clusters

Scaling your cluster involves adjusting its resources based on your application's needs. MongoDB Atlas allows both vertical and horizontal scaling.

Vertical Scaling involves increasing the computational power of your cluster by upgrading or downgrading your tier.

Horizontal Scaling involves distributing your database across multiple servers for better read performance, this is achieved using sharding.

3. Code Examples

Unfortunately, MongoDB Atlas doesn’t provide code-based interaction for monitoring or scaling clusters because these are managed operations that are handled in the MongoDB Atlas UI. However, you can use the MongoDB Atlas API to retrieve metrics and automate scaling operations.

4. Summary

In this tutorial, we've covered how to monitor and scale your MongoDB Atlas clusters. As next steps, consider diving deeper into what each metric in the monitoring tab signifies and how it impacts your database's performance.

For more information, refer to the MongoDB Atlas documentation here.

5. Practice Exercises

Exercise 1:

Take a look at the metrics of your cluster in MongoDB Atlas. Can you identify a metric that seems to be performing poorly?

Exercise 2:

Scale your MongoDB Atlas cluster vertically by upgrading your tier. Note the changes in your cluster's performance.

Exercise 3:

Implement sharding to scale your cluster horizontally and observe the changes in your cluster's performance.

Solutions:

Exercise 1: The solution will depend on your specific cluster's metrics. However, an example could be high CPU usage, indicating that your cluster may need more computational resources.

Exercise 2 & 3: These exercises involve making changes in the MongoDB Atlas UI and observing the impact on your cluster's performance. The exact results will depend on your specific application's needs and the resources of your original cluster.