# Suboptimal engine selection in MemoryDB | Cloud Efficiency Hub Canonical: https://www.pointfive.co/efficiency-hub/inefficiencies/suboptimal-engine-selection-in-memorydb MemoryDB now supports Valkey, a drop-in replacement for Redis OSS offering significant cost and performance advantages. By: Erik Marke Updated: 2026-09-28 [Cloud Efficiency Hub](https://www.pointfive.co/efficiency-hub) # Suboptimal Engine Selection in MemoryDB The short version MemoryDB now supports Valkey, a drop-in replacement for Redis OSS offering significant cost and performance advantages. [Erik Marke](https://www.linkedin.com/in/erikmarke/) Product Owner IT Financial Management & FinOps @ Swiss Post AWS service [AWS MemoryDB](https://www.pointfive.co/efficiency-hub/cloud-services/aws-memorydb) Category [Databases](https://www.pointfive.co/efficiency-hub/service-category/databases) Reference CER-0166 Type Inefficient Configuration ## Explanation Why the waste happens and who it affects. However, many deployments still default to Redis OSS, incurring higher hourly costs and unnecessary data write charges. For compatible workloads, continuing to use Redis OSS instead of Valkey represents a missed opportunity for savings and modernization. ## Billing model The pricing dimensions that drive this cost. MemoryDB charges based on provisioned instance hours, with costs varying by engine type. Valkey instances offer ~30% lower hourly rates and no data write charges up to 10 TB/month. Selecting Redis OSS instead of Valkey can lead to unnecessarily high instance-hour and data-written costs. ## How to detect 3 checks to find it in your estate. - Identify MemoryDB clusters running the Redis OSS engine rather than Valkey - Review the MemoryDB console or cost reporting data for engine metadata - Assess whether workloads are compatible with Valkey (which is Redis API-compatible) ## How to fix 4 ways to remove the waste. - Migrate eligible MemoryDB clusters to use the Valkey engine - Validate API compatibility and performance requirements prior to migration - Use zero-downtime upgrade capabilities where possible for seamless transition - Consider making Valkey the default engine for new MemoryDB deployments ## Documentation Vendor references for pricing and configuration. - [Amazon ElastiCache and Amazon MemoryDB announce support for Valkey aws.amazon.com](https://aws.amazon.com/blogs/database/amazon-elasticache-and-amazon-memorydb-announce-support-for-valkey/) - [Announcing Amazon MemoryDB for Valkey aws.amazon.com](https://aws.amazon.com/about-aws/whats-new/2024/10/amazon-memorydb-valkey/) - [Amazon MemoryDB pricing aws.amazon.com](https://aws.amazon.com/memorydb/pricing/) - [valkey-io/valkey on GitHub github.com](https://github.com/valkey-io/valkey) ## Related inefficiencies [Browse the library](https://www.pointfive.co/efficiency-hub) - AWS MemoryDB CER-0374 ### [Inactive MemoryDB Cluster](https://www.pointfive.co/efficiency-hub/inefficiencies/inactive-memorydb-cluster) MemoryDB clusters are billed for every node, primary and replica, for every hour the cluster exists, whether or not any client is connected. Clusters created for a proof of concept, a load test, a migration rehearsal or a feature that was... Databases - Databricks CER-0332 ### [Missing Partition Pruning in Delta Lake Table Queries](https://www.pointfive.co/efficiency-hub/inefficiencies/missing-partition-pruning-in-delta-lake-table-queries-on-databricks) When Delta Lake tables are partitioned by specific columns - such as date, region, or tenant identifier - the query engine can use partition pruning to limit data scans to only the relevant subset of files. However, when queries against... Databases - AWS RDS CER-0322 ### [Non-Production RDS SQL Server Using Standard or Enterprise Edition Instead of Developer Edition](https://www.pointfive.co/efficiency-hub/inefficiencies/non-production-rds-sql-server-using-standard-or-enterprise-edition-instead-of-developer-edition) Amazon RDS for SQL Server uses a License Included pricing model where the hourly instance rate bundles Microsoft SQL Server licensing fees on a per-vCPU basis. When non-production workloads - such as development, testing, staging, QA, or... Databases --- Source: the public page above. Product screenshots and illustrative interfaces are examples, not live customer data.