Best Practice 18.2 – Use cost as a key consideration for EC2 instance selection

By selecting the appropriate SAP Certified EC2 instances for your workload, it is possible to optimize for cost. Perform a thorough analysis of each system, ensuring that decisions are data driven where possible. Generic guidance can be found in the Well-Architected Framework Cost Optimization Pillar - Cost-Effective Resources.

Suggestion 18.2.1 – Select the latest generation instances available within your Region

The latest generation of Amazon EC2 instances often offers the lowest cost with better performance and should be used if available and certified for the deployment scenario.

Suggestion 18.2.2 – Balance cost with performance requirements

Each SAP supported Amazon EC2 instance family will provide specific performance measured in SAPS. You should evaluate each instance family based on your performance requirements. An understanding of the cost per SAPS and cost per GiB ratios is recommended.

If a workload component requires more memory over SAPS (CPU), you should select the instance family that provides the lowest cost per GiB memory. If the component requires more SAPS (CPU) over memory, you should select the instance family that provides the lowest cost per SAPS.

SAP Certified instance families powered by an AMD processor typically provide a 10% cost saving over the comparable Intel-based EC2. For example, the C5a is 10% lower cost than the C5 family for the same performance KPIs.

For non-production SAP HANA workloads consider using one of the instance families that meets the requirements detailed in SAP Note: 2271345 - Cost-Optimized SAP HANA Hardware for Non-Production Usage [Requires SAP Portal Access].

Suggestion 18.2.3 – Review the predictability of your growth profile and peak capacity requirements

An existing SAP landscape on AWS or a homogeneous migration is likely to have more predictable growth and usage patterns than a new greenfield implementation or heterogeneous migration.

For systems where you lack data on historical growth, you should consider the cost benefits of selecting an EC2 instance size sufficient for the short or medium term growth. Plan to scale the instance size as your requirement changes. You should ensure that your architecture design provides the flexibility to move between different EC2 instance families as your resource consumption changes.

Similarly, you should evaluate that changes to peak capacity have been accounted for.

When sizing an SAP HANA environment consider not only the database size but also the working memory requirement. Consult SAP HANA sizing reports and tools to estimate your size and usage.

Suggestion 18.2.4 – Consider instance commitment flexibility

When a component (for example, SAP HANA database) needs to scale up during the commitment period, evaluate if this will result in moving to a different instance family. This will impact your pricing model selection.