It’s a scenario that no website owner wants to face: your website, which has been running smoothly for months, suddenly goes down. Panic sets in as users can’t access your services, and business slows down drastically. In my case, the traffic to my website spiked unexpectedly, and my EC2 instance could no longer handle the load. I realized that the only solution to get my site back up and running was to scale my EC2 instance vertically – but what does that even mean, and how do you do it?

In this article, I will share how I tackled the problem of scaling my EC2 instance when it wasn’t enough to meet the demand. If you find yourself in a similar situation, keep reading to learn how vertical scaling can be your best option.

What is Amazon EC2?

Amazon Elastic Compute Cloud (EC2) is one of the most fundamental services offered by AWS. EC2 allows users to rent virtual servers, known as instances, that can run applications and services. Whether it’s for hosting websites, processing data, or running a web application, EC2 is versatile and highly scalable. Instances come in different types, optimized for various workloads, and can be resized based on the requirements of the application.

Upscaling and Downscaling EC2 Instances:

Upscaling an EC2 instance refers to increasing the resources (such as CPU, memory, or storage) of an existing instance to accommodate higher workloads or increased traffic. This process, also known as vertical scaling, is ideal when your application requires more power to handle demand without the complexity of managing multiple instances. On the other hand, downscaling involves reducing the resources of an EC2 instance when demand decreases or to optimize costs. By downsizing, you can adjust the instance size to align with current usage, ensuring efficient resource allocation without overpaying for unused capacity. Both upscaling and downscaling are essential techniques for managing cost and performance in cloud environments, offering flexibility to adapt to changing requirements.

The Importance of EC2 Scaling: Handling Growing Demand

Scaling your EC2 instance is crucial for maintaining the performance and availability of your applications. As web traffic fluctuates or as workloads increase, ensuring that your instance can handle the load without crashing is vital. AWS provides the flexibility of both horizontal and vertical scaling to meet these demands.

• Horizontal Scaling: This involves adding more EC2 instances to distribute the load across multiple servers. It’s ideal for applications with fluctuating traffic and high availability requirements.

• Vertical Scaling: In contrast, vertical scaling involves upgrading the resources of an existing EC2 instance (such as CPU, RAM, or storage). This method is effective when the instance needs more power to handle increased demand.

Horizontal Scaling vs. Vertical Scaling: What’s the Difference?

Understanding the difference between horizontal and vertical scaling is key to choosing the right approach. Let’s break it down:

1. Horizontal Scaling: This method involves adding more EC2 instances to handle increasing load. It’s easier to automate and offers higher fault tolerance because the load is distributed across multiple instances.

   • Example: A web application with fluctuating user traffic.

   • Pros: Scalable, fault-tolerant, and cost-effective for large-scale applications.

   • Cons: Higher complexity due to the need for load balancing and managing multiple instances.

2. Vertical Scaling: This involves upgrading the resources of a single EC2 instance (e.g., adding more memory, CPU power, or storage). It’s simple and involves fewer management complexities, but is limited by the maximum instance size.

   • Example: A database server with increased memory or CPU demands.

   • Pros: Simpler to manage and easy to implement.

   • Cons: Limited by instance size and can be costly if resources remain unused.

Now that you know what vertical scaling is, let’s go through the steps to upgrade your EC2 instance to meet the growing demand.

Steps to Stop and Change EC2 Instance Type for an Existing EC2 Instance:

1. Stop the EC2 Instance:

Go to the EC2 Dashboard in the AWS Management Console.

In the Instances section, select the current or existing EC2 instance whose type you want to change.

Click on the Instance State dropdown and choose Stop.

Confirm the action. Stopping the instance will cause it to shut down gracefully. You are not charged for the instance usage while it’s stopped, but you will still be charged for any associated storage (e.g., EBS volumes).

1. • Important: Make sure the instance is stopped and not terminated. You cannot change the instance type of a terminated instance.

2. Change the Instance Type:

Once the existing EC2 instance is stopped, click on the Actions button.

Under Instance Settings, choose Change Instance Type.

A new window will pop up with a list of available instance types. Select the new instance type that fits your needs.

After selecting the new instance type, click on Change to confirm.

1. Restart the EC2 Instance:

Once the instance type has been changed, go back to the Instance State dropdown and choose Start.

Your current or existing EC2 instance will now start with the new instance type.

Notes:

• Ensure that the instance type you want to change to is supported by the instance’s availability zone.

• You may need to adjust other settings, such as Elastic IPs or security groups, depending on your changes.

• If you are using Amazon EBS-backed instances, the instance will retain its data during the stop/start process.

Cost Considerations:

• After changing the instance type, the pricing will be based on the new instance type. Always review the pricing for the new instance type on the AWS EC2 Pricing Page.

Why Vertical Scaling Was the Right Choice for My Website

By vertically scaling my EC2 instance, I was able to resolve the issue of increased traffic on my website without the complexity of managing multiple instances. The process was simple and straightforward, and it allowed me to keep my website running smoothly. While vertical scaling does come with some cost considerations and limitations, it was the best option for my use case.

As your website or application grows, consider vertical scaling if you expect increased resource demand but don’t want to manage multiple EC2 instances. However, for more complex and large-scale environments, horizontal scaling might be a better option.

References:

• How to Change the Instance Type of an EC2 Instance

• Vertical Scaling and Horizontal Scaling in EC2 Instances

• AWS EC2 Pricing