Evaluate Cost When Selecting Services - Cost Optimization Pillar

Evaluate Cost When Selecting Services

Identify organization requirements: When selecting services for your workload, it is key that you understand your organization priorities. Ensure that you have a balance between cost and other Well-Architected pillars, such as performance and reliability. A fully cost-optimized workload is the solution that is most aligned to your organization’s requirements, not necessarily the lowest cost. Meet with all teams within your organization to collect information, such as product, business, technical and finance.

Analyze all workload components: Perform a thorough analysis on all components in your workload. Ensure that balance between the cost of analysis and the potential savings in the workload over its lifecycle. You must find the current impact, and potential future impact, of the component. For example, if the cost of the proposed resource is $10/month, and under forecasted loads would not exceed $15/month, spending a day of effort to reduce costs by 50% ($5 a month) could exceed the potential benefit over the life of the system. Using a faster and more efficient data-based estimation will create the best overall outcome for this component.

Workloads can change over time, the right set of services may not be optimal if the workload architecture or usage changes. Analysis for selection of services must incorporate current and future workload states and usage levels. Implementing a service for future workload state or usage may reduce overall costs by reducing or removing the effort required to make future changes.

AWS Cost Explorer and the CUR can analyze the cost of a Proof of Concept (PoC) or running environment. You can also use the AWS Simple Monthly Calculator or the AWS Pricing Calculator to estimate workload costs.

Managed Services: Managed services remove the operational and administrative burden of maintaining a service, which allows you to focus on innovation. Additionally, because managed services operate at cloud scale, they can offer a lower cost per transaction or service.

Consider the time savings that will allow your team to focus on retiring technical debt, innovation, and value-adding features. For example, you might need to “lift and shift” your on-premises environment to the cloud as rapidly as possible and optimize later. It is worth exploring the savings you could realize by using managed services that remove or reduce license costs.

Usually, managed services have attributes that you can set to ensure sufficient capacity. You must set and monitor these attributes so that your excess capacity is kept to a minimum and performance is maximized. You can modify the attributes of AWS Managed Services using the AWS Management Console or AWS APIs and SDKs to align resource needs with changing demand. For example, you can increase or decrease the number of nodes on an Amazon EMR cluster (or an Amazon Redshift cluster) to scale out or in.

You can also pack multiple instances on an AWS resource to enable higher density usage. For example, you can provision multiple small databases on a single Amazon Relational Database Service (Amazon RDS) DB instance. As usage grows, you can migrate one of the databases to a dedicated RDS DB instance using a snapshot and restore process.

When provisioning workloads on managed services, you must understand the requirements of adjusting the service capacity. These requirements are typically time, effort, and any impact to normal workload operation. The provisioned resource must allow time for any changes to occur, provision the required overhead to allow this. The ongoing effort required to modify services can be reduced to virtually zero by using APIs and SDKs that are integrated with system and monitoring tools, such as Amazon CloudWatch.

Amazon Relational Database Service (RDS), Amazon Redshift, and Amazon ElastiCache provide a managed database service. Amazon Athena, Amazon Elastic Map Reduce (EMR), and Amazon OpenSearch Service provide a managed analytics service.

AWS Managed Services (AMS) is a service that operates AWS infrastructure on behalf of enterprise customers and partners. It provides a secure and compliant environment that you can deploy your workloads onto. AMS uses enterprise cloud operating models with automation to allow you to meet your organization requirements, move into the cloud faster, and reduce your on-going management costs.

Serverless or Application-level Services: You can use serverless or application-level services such as AWS Lambda, Amazon Simple Queue Service (Amazon SQS), Amazon Simple Notification Service (Amazon SNS), and Amazon Simple Email Service (Amazon SES). These services remove the need for you to manage a resource, and provide the function of code execution, queuing services, and message delivery. The other benefit is that they scale in performance and cost in line with usage, allowing efficient cost allocation and attribution.

For more information on Serverless, refer to the Well-Architected Serverless Application lens whitepaper.

Analyze the workload for different usage over time: As AWS releases new services and features, the optimal services for your workload may change. Effort required should reflect potential benefits. Workload review frequency depends on your organization requirements. If it is a workload of significant cost, implementing new services sooner will maximize cost savings, so more frequent review can be advantageous. Another trigger for review is change in usage patterns. Significant changes in usage can indicate that alternate services would be more optimal. For example, for higher data transfer rates a direct connect service may be cheaper than a VPN, and provide the required connectivity. Predict the potential impact of service changes, so you can monitor for these usage level triggers and implement the most cost effective services sooner.

Licensing costs: The cost of software licenses can be eliminated through the use of open source software. This can have significant impact on workload costs as the size of the workload scales. Measure the benefits of licensed software against the total cost to ensure that you have the most optimized workload. Model any changes in licensing and how they would impact your workload costs. If a vendor changes the cost of your database license, investigate how that impacts the overall efficiency of your workload. Consider historical pricing announcements from your vendors for trends of licensing changes across their products. Licensing costs may also scale independently of throughput or usage, such as licenses that scale by hardware (CPU bound licenses). These licenses should be avoided because costs can rapidly increase without corresponding outcomes.

You can use AWS License Manager to manage the software licenses in your workload. You can configure licensing rules and enforce the required conditions to help prevent licensing violations, and also reduce costs due to license overages.