Review of the AWS Right Sizing Tool: Helpful or Clunky?
Amazon Web Services (AWS) provides a treasure trove of documents and CloudFormation templates in their AWS Solutions portal, including AWS right sizing, the AWS instance scheduler, a chatbot framework, and more. These solutions can be used as-is for immediate integration into your existing environment, or can be the starting point for developing your own unique toolsets. Today, we’re reviewing the AWS Right Sizing tool to see how much it can help you optimize your infrastructure.
AWS Right Sizing: What It Does
AWS offers a variety of types and sizes of EC2 instances. That means that it’s perfectly possible to select an instance type that’s too large for your actual needs, which means you’ll be paying more than necessary. In fact, the data shows that this is happening most of the time. The AWS Right Sizing tool exists to help users find the correct instance size to meet their needs at the lowest cost.
The tool uses a CloudFormation template that deploys infrastructure and scripts needed to make right sizing recommendations for your AWS account. This infrastructure includes an EC2 instance that will run python scripts, a 2-node Redshift cluster for the right sizing analysis, and an S3 bucket for the raw CloudWatch data and the final CSV output. The total cost of this deployment in the us-east-1 region is $0.65 per hour.
The basis of the right sizing logic is to look at the Max CPU from the past 2 weeks of CloudWatch data for each EC2 instance. If the max CPU is above 50% at any point, then it will not recommend a change, but if it is always below 50% then it will attempt to find the cheapest instance size that matches the I/O, memory, network, and at least the max CPU that was found. The final output is a CSV file that includes information about the existing instance sizes, the utilization of those instances, the recommended instance size, and the cost saved per month.
Worth the hassle?
Based on the logic above, the AWS Right Sizing tool does a very basic level of recommendation for instance sizing. There are a few scenarios where these recommendations may not be helpful, such as applications that are memory-intensive or cases where the instance needs to be a larger size than it currently is. The tool also only spits out a CSV with the recommendations, which means you still have to make decisions and take actions based on those recommendations. The CSV file looks like this:
If those recommendations don’t seem to fit what you’re looking for, the nice thing is they offer the full stack, along with all scripts and CloudFormation templates, as an open-source repository. This means you can take the core of the recommendation engine and tweak it to follow your own logic for customized recommendations, or even use it to trigger the resizing of the instance. AWS also offers Trusted Advisor as a part of their Business-level and Enterprise-level support plans, which can offer right sizing recommendations in real time (amongst other health checks and recommendations).
Overall, this AWS right sizing tool can either be a useful check-up tool for your environment, or the basis for your own cost-optimization initiative, but many users will want a more out-of-the-box automated solution for this.
Since changing server sizes and timing this with maintenance windows can be a hassle, ParkMyCloud has introduced a feature to automate the resizing of your EC2 instances. Interested? Check it out with a free trial.
Originally published at www.parkmycloud.com on February 21, 2019.