How to find idle AWS resources to reduce cost

Tal Shladovsky
March 23, 2023
5
min. read

TL;DR

  • Finding idle resources in AWS involves monitoring resource usage and analyzing usage patterns to identify resources that are not being utilized to their full potential.
  • This operation can help optimize resource allocation, reduce costs, and improve overall system efficiency.
  • AWS offers various native tools and services to assist with idle resource detection, including CloudWatch, Trusted Advisor, and Cost Explorer.
  • Alternatively, Lightlytics offers an easier and scalable way to find and detect idle resources with advanced search capabilities and architectural standards.

What is an idle resource in AWS?

In Amazon Web Services (AWS), an idle resource is a computing resource that is provisioned but not actively utilized or performing any meaningful work or processing. This can include various types of resources, such as virtual machines, databases, storage volumes, load balancers, and other services that are provisioned but not actively used.  Idle resources in AWS can consume unnecessary computing power and resources, leading to higher costs and reduced system efficiency. It is important to detect and address idle resources to optimize resource utilization, reduce costs, and improve overall system performance.  AWS provides various tools and services to help users identify and manage idle resources, such as AWS CloudWatch, AWS Trusted Advisor and AWS Cost Explorer. By regularly monitoring and optimizing idle resources, organizations can ensure they are only paying for the resources they need and are making the most of their AWS investment.

Why is it important to detect idle resources in AWS?

It is important to detect idle resources in AWS for several reasons:

  1. Cost Optimization: Idle resources in AWS can continue to incur charges even when not in use, leading to unnecessary spending. By detecting and removing idle resources, you can optimize your usage and reduce costs.
  1. Resource Allocation: Unused resources tie up resources that could be better used for other purposes. By detecting idle resources, you can free up these resources and allocate them to other applications or services that need them.
  1. Security: Idle resources can create security risks by providing an attack surface that is not actively monitored or maintained. By detecting and removing idle resources, you can reduce your security risk and improve your overall security posture.
  1. Compliance: Unused resources can create compliance risks by leaving data or applications exposed to unauthorized access. By detecting and removing idle resources, you can improve your compliance with industry standards and regulations.

Overall, detecting and managing idle resources in AWS is important for optimizing costs, improving resource allocation, enhancing security, and ensuring compliance. It is an essential part of managing your cloud infrastructure and can help you make the most of your AWS investment.

Which AWS resources are prone to becoming idle?

There are several resources in AWS that can become idle, which may result in unnecessary costs.  
Here's a list of thesetop resources:

  1. EC2 instances: EC2 instances are virtual servers that can be launched and terminated as per the user's requirements. However, if an EC2 instance is not in use or underutilized, it can become an idle resource.
  1. Elastic Load Balancers (ELBs): ELBs distribute incoming network traffic across multiple EC2 instances to improve availability and fault tolerance. If an ELB is not receiving any traffic or not in use, it can become an idle resource.
  1. Auto Scaling groups: Auto Scaling groups automatically adjust the number of EC2 instances in response to changes in demand. If the demand for an application decreases, the Auto Scaling group may keep running unnecessary EC2 instances, which can become idle resources.
  1. RDS instances: RDS is a managed relational database service provided by AWS. If an RDS instance is not in use or underutilized, it can become an idle resource.
  1. Elastic Block Store (EBS) volumes: EBS volumes are virtual hard drives that can be attached or detached from EC2 instances. If an EBS volume is not attached to any instance or not in use, it can become an idle resource.
  1. S3 buckets: S3 is a scalable and highly available object storage service provided by AWS. If an S3 bucket is not in use or has not been accessed for a long time, it can become an idle resource.

How to find idle resources in AWS?

AWS provides several tools and services to help find idle compute and database resources, such as:

  1. AWS Cost Explorer: This tool allows you to visualize and analyze your AWS spending over time. You can use it to identify idle resources by looking for instances or databases that have low or no utilization over a period.
  1. AWS Trusted Advisor: Trusted Advisor is a service that inspects your AWS environment and provides recommendations for optimizing your resources. It includes checks for idle resources, and it can recommend actions such as stopping or terminating instances that have been idle for  a certain period.
  1. Amazon CloudWatch: CloudWatch is a monitoring service that provides metrics and logs for AWS resources. You can use it to create alarms that trigger when a resource's utilization falls below a certain threshold, indicating that it may be idle.
  1. AWS Lambda: Lambda is a serverless computing service that allows you to run code in response to events. You can use it to create a custom script or function that periodically checks for idle resources and takes action, such as sending an alert or stopping the resource.
  1. AWS Systems Manager: Systems Manager provides a suite of tools for managing AWS resources. You can use it to create automation workflows that check for idle resources and take actions based on the results.

By using these tools and services, you can detect idle resources in your AWS environment and take action to optimize your usage and reduce costs.

The New & Easy Way to identify idle resources with Lightlytics

Using Lightlytics Architectural Standards, you can quickly identify potentially idle resources that can be easily optimized. You can use Lightlytics’s out-of-the-box Idle Resources rules, or you can create your own custom rules using tags and various idle resources attributes. By using these capabilities, you can review the total predicted monthly cost of each rule, and a breakdown of cost per violated resource within each rule.

Example #1 architectural standard: EC2 instances appear to be idle

An EC2 instance is considered idle when both of the following terms are met:
1. The average CPU utilization has been less than 3% for the last 14 days  
2. The average Network I/O has been less than 5 MB for the last 14 days

This rule can also help you work with the AWS Well-Architected Framework.

Review rule violations: When there are violations of this rule (or any rule in our architectural standards), this view shows each violated resource including the related monthly costs.

Detailed look at the monthly cost of this violation in the Lightlytics UI
Monthly cost breakdown per resource as a result of violations of the rule

Example #2 architectural standard: NAT Gateways appear to be idle

A NAT Gateway is considered idle in case there were no connections via the NAT Gateway for the last 14 days.

Lightlytics architectural standards indicating that the NAT gateway is idle.

Review rule violations: When there are violations of this rule (or any rule in our architectural standards), this view shows each violated resource including the related monthly costs.

Detailed look at the monthly cost of this violation in the Lightlytics UI

Summary

In conclusion, identifying and managing idle resources in AWS is a critical aspect of cost optimization and resource utilization in a cloud computing environment. By using the various tools and services provided by AWS, such as AWS CloudWatch, AWS Trusted Advisor, and AWS Cost Explorer, you can monitor and analyze resource usage patterns to identify idle resources and take appropriate actions, such as shutting down or resizing resources, to reduce costs and improve system efficiency.  

Regularly monitoring and managing idle resources in AWS can help organizations avoid unnecessary expenses and maximize their return on investment in cloud computing. As organizations increasingly rely on cloud computing services, identifying and managing idle resources will continue to play a crucial role in maintaining optimal performance and cost efficiency in AWS.

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