Cut costs and simplify operations with writable warm storage in Amazon OpenSearch Service

This article introduces writable warm storage in Amazon OpenSearch Service, a new feature that eliminates costly migration cycles by enabling direct writes to warm storage backed by Amazon S3.

• Writable warm uses OpenSearch Optimized (OI2) instances for S3-backed durable storage with write capability
• Reduces infrastructure costs by up to 48% with 3-year Reserved Instances compared to UltraWarm
• Eliminates expensive warm-to-hot-to-warm migration cycles for late-arriving data and compliance corrections
• Supports Reserved Instance pricing (31-52% savings) and Database savings plans (22% savings)
• Offers flexible instance sizing from oi2.large to oi2.16xlarge versus UltraWarm's two fixed sizes
• Delivers comparable or better search performance than UltraWarm on most query types
• Simplifies operations by removing force merge, snapshot, and complex scheduling requirements
• Requires OpenSearch Service version 3.3+ and OI2 instance family support

Writable warm storage provides a cost-effective, operationally simpler alternative to UltraWarm for workloads requiring occasional updates to historical data.