Suboptimal Use of Intel-Based Instances in OpenSearch

Explanation

AWS Graviton processors are designed to deliver better price-performance than comparable Intel-based instances, often reducing cost by 20-30% at equivalent workload performance. OpenSearch domains running on older Intel-based families consume more spend without providing additional capability. Since Graviton-powered instance types are functionally identical in features and performance for OpenSearch, continuing to run on Intel-based clusters represents unnecessary inefficiency.

Relevant Billing Model

OpenSearch is billed based on the underlying EC2 instance hours consumed by the cluster, plus storage and data transfer. Choosing less efficient Intel-based instance types (e.g., `m5`, `r5`, `i3`, `i4i`) results in higher cost per unit of performance compared to Graviton-based instances (`m6g`, `c6g`, `r6g`, `i4g`).

Detection

• Review all active OpenSearch domains and identify clusters running on Intel-based instance types that have equivalent Graviton alternatives
• Assess whether workload performance requirements (CPU, memory, IOPS) could be met by moving to Graviton families
• Confirm OpenSearch version compatibility to ensure upgrade paths to supported Graviton instance types
• Evaluate whether production and non-production domains are consistently aligned with optimal instance families

Remediation

• Migrate OpenSearch domains from Intel-based instances (e.g., `m5`, `r5`, `i4i`) to equivalent Graviton families (`m6g`, `c6g`, `r6g`, `i4g`)
• Leverage in-place instance type updates for clusters where supported to minimize downtime
• Benchmark performance after migration to validate expected cost-performance improvements