# Suboptimal ElastiCache Engine Selection

Canonical: https://www.pointfive.co/efficiency-hub/inefficiencies/suboptimal-elasticache-engine-selection

[Cloud Efficiency Hub](https://www.pointfive.co/efficiency-hub) 

# Suboptimal ElastiCache Engine Selection

## Explanation

Many workloads default to using Redis or Memcached without evaluating whether a lighter or more efficient engine would provide equivalent functionality at lower cost. Valkey is a Redis-compatible, open-source engine supported by ElastiCache that may offer improved price-performance and licensing benefits. For read-heavy or stateless workloads that don't require Redis-specific features (e.g., persistence, advanced replication), Valkey can often be used as a drop-in replacement. Memcached, while simple, lacks key features like replication and persistence, and may be less cost-effective for certain access patterns. Choosing the wrong engine can result in overpaying for capabilities that aren't needed - or missing opportunities to optimize.

## Relevant Billing Model

ElastiCache is billed per instance-hour based on instance type and engine. While pricing is nominally similar across engines, performance and resource efficiency may vary significantly depending on workload and engine selection.

## Detection

- Review the engine type for each ElastiCache cluster (Redis, Memcached, Valkey)

- Identify Redis clusters that don't use features like persistence, pub/sub, or complex data types

- Evaluate whether Valkey would be a compatible and more efficient replacement

- Assess historical reasons for engine choice (e.g., legacy defaults vs. actual workload needs)

## Remediation

- For Redis-compatible but non-persistent workloads, consider migrating to Valkey

- If using Memcached, reevaluate whether Redis or Valkey offers better price-performance

- Note that engine migration typically requires cluster recreation and data migration - plan accordingly

- Incorporate engine selection as part of architecture reviews for new cache deployments

## Relevant Documentation

[Submit Feedback](https://hub.pointfive.co/inefficiencies/suboptimal-elasticache-engine-selection)

## At a glance

Reference

CER-0105

Cloud provider

AWS

Service

AWS ElastiCache

Category

[Databases](https://www.pointfive.co/efficiency-hub/service-category/databases)

Inefficiency type

Suboptimal Configuration

## Contributed by

- ### Yulia Perlis

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Source: the public page above. Product screenshots and illustrative interfaces are examples, not live customer data.