Using the appropriate instances and resources for your workload is key to cost savings. For example, a reporting process might take five hours to run on a smaller server but one hour to run on a larger server that is twice as expensive. Both servers give you the same outcome, but the smaller server incurs more cost over time.
A well-architected workload uses the most cost-effective resources, which can have a significant and positive economic impact. You also have the opportunity to use managed services to reduce costs. For example, rather than maintaining servers to deliver email, you can use a service that charges on a per-message basis.
AWS offers a variety of flexible and cost-effective pricing options to acquire instances from EC2 and other services in a way that best fits your needs. On-Demand Instances allow you to pay for compute capacity by the hour, with no minimum commitments required. Reserved Instances allow you to reserve capacity and offer savings of upto 75% off On-Demand pricing. With Spot Instances, you can leverage unused Amazon EC2 capacity and offer savings of up to 90% off On-Demand pricing. Spot Instances are appropriate where the system can tolerate using a fleet of servers where individual servers can come and go dynamically, such as stateless web servers, batch processing, or when using HPC and big data.
Appropriate service selection can also reduce usage and costs; such as CloudFront to minimize data transfer, or completely eliminate costs, such as utilizing Amazon Aurora on RDS to remove expensive database licensing costs.
COST 4: How do you evaluate cost when you select services?
Amazon EC2, Amazon EBS, and Amazon S3 are building-block AWS services. Managed services, such as Amazon RDS and Amazon DynamoDB, are higher level, or application level, AWS services. By selecting the appropriate building blocks and managed services, you can optimize this workload for cost. For example, using managed services, you can reduce or remove much of your administrative and operational overhead, freeing you to work on applications and business-related activities.
COST 5: How do you meet cost targets when you select resource type and size?
Ensure that you choose the appropriate resource size for the task at hand. By selecting the most cost effective type and size, you minimize waste.
COST 6: How do you use pricing models to reduce cost?
Use the pricing model that is most appropriate for your resources to minimize expense.
COST 7: How do you plan for data transfer charges?
Ensure that you plan and monitor data transfer charges so that you can make architectural decisions to minimize costs. A small yet effective architectural change can drastically reduce your operational costs over time.
By factoring in cost during service selection, and using tools such as Cost Explorer and AWS Trusted Advisor to regularly review your AWS usage, you can actively monitor your utilization and adjust your deployments accordingly.