Monitoring AWS Costs and Resource Utilization with Amazon SNS

There are several ways of cloud cost optimization with Amazon SNS, and in this article, we’ll explore one method, which is Amazon SNS, to receive alerts about cost and resource utilization.

Almost everyone working with AWS has used SNS at some point, and if you’re a beginner, you’ve likely at least heard of it. In this article, I’ll walk you through how to leverage the Simple Notification Service (SNS) to monitor AWS costs and resources effectively.

Why Amazon SNS?

The very first question that may come to mind is: why SNS?

Amazon Simple Notification Service (SNS) is a versatile solution that can be integrated with AWS CloudWatch and AWS Budgets to trigger real-time notifications across multiple endpoints such as email, AWS Lambda, SMS, Slack, and more.

These real-time notifications ensure that cost anomalies and resource overutilization can be addressed immediately.

One of the major advantages of Amazon SNS is its scalability. It can trigger alerts across multiple channels at once, providing the right visibility to different stakeholders in real time. Even in the rare case where one channel fails, other endpoints will still receive the alerts, ensuring that the responsible teams can take timely action.

Moreover, Amazon SNS is not limited to alerting. It can also be used to perform automated optimization tasks by triggering Lambda functions to stop idle or unused resources, or to resize over-provisioned resources. This makes SNS not just a monitoring tool, but also a mechanism for taking corrective action when needed.

Finally, when it comes to cost, SNS itself is very cost-effective compared to building a custom alerting system. It is simple, fully managed, and economical. To give you an idea, the first 1 million requests per month are free, making it a budget-friendly option for organizations of any size.

Topics in Amazon SNS

At the core of SNS lies the topic, which serves as the central communication unit and a logical access point where publishers send messages and subscribers receive them.

AWS Simple Notification Service topics enable a decoupled, scalable, reliable, and flexible workflow. Publishers don’t need to know the details of subscribers, making the system loosely coupled. Scalability is built in, as a single topic can support millions of subscribers. Reliability and flexibility come from the fact that subscribers can be entirely different systems, ranging from applications to monitoring tools.

Topics are commonly used for alerting teams in real time about cost and resource utilization, application events, or even triggering automation workflows.

Integrating SNS with AWS Budgets for Cost Alerts

Now that we understand the value of SNS, let’s walk through the process of integrating it with AWS Budgets to receive alerts whenever your costs exceed a predefined threshold.

The process is straightforward:

1. Log in to your AWS Account
   Access the AWS Management Console with your credentials.
2. Navigate to Billing and Cost Management
   From the console, open the Billing and Cost Management dashboard.
3. Go to Budgets
   In the left-hand menu, select Budgets.
4. Create a New Budget
   Click Create budget and configure the budget details.
5. Configure Alerts

• Set your threshold amount (e.g., when actual or forecasted costs reach 80% of your budget).
• Select the option for Amazon SNS alerts.
• Provide the SNS Topic ARN you created earlier.

6. Review and Confirm
   Double-check your configuration and confirm to save the budget.

How It Works

From this point onward, whenever your monthly budget threshold is exceeded, AWS Budgets will automatically trigger the SNS topic. All subscribers to that topic, whether via email, SMS, Slack, Lambda functions, or other endpoints, will instantly receive the alert. This ensures that the relevant teams are informed in real time and can take timely action.

Setting Up an Amazon SNS Topic for Resource Utilization

In addition to monitoring costs, SNS can also be used to track resource utilization.
For example, let’s take an AWS EC2 instance where we want to receive a notification whenever CPU utilization reaches 70% or higher. This allows the relevant team to take timely action before performance is impacted.

Let’s assume we have an EC2 instance already running. As we know, AWS provides several pre-configured instance metrics through Amazon CloudWatch, and CPU utilization is one of the most important among them.

Steps to Configure:

1. Navigate to CloudWatch
   a) Open the AWS Management Console and go to CloudWatch.
2. Select Metrics
   a) Click on All Metrics.
   b) Choose EC2.
   c) Locate the CPUUtilization metric for your specific instance.
3. Create an Alarm
   a) Select Create Alarm.
   b) On the configuration page, define the threshold (e.g., CPU utilization ≥ 70%).

4. Configure Actions
   In the Actions section, provide the Amazon SNS Topic details.
   This ensures the relevant team is notified via the subscribed protocols (Email, SMS, Slack, etc.) whenever the threshold is breached.
   Optionally, you can define additional automated actions such as triggering a Lambda function, scaling policies via an Auto Scaling Group, or actions at the EC2 level. (We’ll cover these in detail in another blog.)

5. Name the Alarm
   Assign a descriptive name to your alarm for easy identification.
6. Review and Create
   Review the configurations and create the alarm linked to your SNS topic.

Outcome

With this integration in place, whenever the CPU utilization of your AWS EC2 instance reaches 70% or higher, CloudWatch will trigger the SNS topic. All subscribed endpoints, whether Slack, Email, or SMS will immediately receive the notification, enabling teams to take timely action.

Conclusion

Amazon SNS makes AWS cost and resource monitoring both proactive and practical. By pairing SNS with AWS Budgets and CloudWatch, you get real-time visibility into spend and utilization, plus the option to trigger automated remediation when thresholds are reached.

This combination scales effortlessly across teams and channels, Email, SMS, Slack, Lambda, and more, so the right people are alerted at the right time.