Migration from ElastiCache Redis to ElastiCache Valkey: Key Considerations

Overview

This document provides a detailed guide to migrating from Redis to Amazon ElastiCache for Valkey. It covers the following areas:

• Cost Efficiency

• AWS Backing and Feature Enhancements

• Seamless Transition Process

• Compatibility with Redis Commands

• Additional Benefits

• Answers to Key Questions

• References

1. Cost Efficiency

Elasticache for Valkey vs Redis

• Cost Savings: ElastiCache for Valkey is generally more affordable than ElastiCache for Redis. The potential savings can vary depending on your existing Redis setup and ElastiCache footprint.

2. AWS Backing and Feature Enhancements

• Active Maintenance: Valkey is actively maintained by AWS, ensuring it stays current with evolving enterprise needs. Key contributors, including Madelyn Olson, a principal AWS engineer, play a pivotal role in its development.

• Enterprise-Centric Evolution: AWS actively listens to feedback from its enterprise customers, ensuring that Valkey continues to be enhanced with features tailored to meet these specific needs.

3. Seamless Transition Process

In-Place Replacement

• Minimal Downtime: The migration to Valkey will be a seamless in-place replacement for Redis. AWS ensures that the transition involves minimal downtime. In many cases, this can be reduced to zero downtime, depending on your setup and the complexity of your data.

• Upgrade Strategy: The transition to Valkey is similar to a version upgrade of Redis, meaning that it can be performed with minimal disruption to service. Following standard upgrade practices, such as data backups and testing, is recommended.

4. Compatibility with Redis Commands

• Full Compatibility: Valkey is a fork of Redis and supports all Redis commands, ensuring that your applications will continue to function without requiring any code modifications.

• Upgrade Process: The upgrade from Redis to Valkey can be considered as an in-place upgrade, and it follows similar processes to upgrading Redis versions. Be sure to conduct proper testing and ensure data integrity during this process.

5. Additional Benefits of Valkey

Valkey offers several advantages over Redis that can enhance your system's performance and flexibility:

• Improved Multi-Threading Support: Valkey enhances performance by providing better multi-threading support, allowing for greater efficiency in handling concurrent operations.

• Community and Open Licensing: Valkey benefits from strong community support and operates under a permissive open-source license, ensuring long-term sustainability and continued innovation.

• Enhanced Observability: Valkey includes advanced observability features such as per-slot metrics, making it easier to monitor and gain visibility into your cache's behavior.

• Broad Industry Support: Valkey has backing from major organizations such as AWS, Google, and Oracle, which contributes to its ongoing development and broad industry adoption.

6. Answers to Key Migration Questions

Q1: Will there be downtime during the in-place upgrade of a single-node Redis instance to Valkey?

• Answer: Yes, there will be some downtime during the in-place upgrade of a single-node Redis instance to Valkey. This downtime is usually short, ranging from a few seconds to a few minutes, depending on factors like the size of your data and the upgrade complexity.

Q2: Will all the data be preserved during the upgrade?

• Answer: Yes, your data will be preserved during the upgrade. AWS ensures a seamless migration of all in-memory data, including keys, values, and TTLs (Time-to-Live). There should be no data loss during the process.

Q3: Do we need to make any changes on the application side for this upgrade?

• Answer: No, no changes to the application code are required for the upgrade from Redis to Valkey, as Valkey is fully compatible with Redis. However, there may be instances where the application caches the endpoints of the systems it communicates with, which could cause it to send traffic to old Redis endpoints. In such cases, an application restart or redeployment may be necessary to clear the cached endpoints.

Q4: Will the URL change if we move from Redis to Valkey?

• Answer: No, the URL will remain unchanged when migrating from Redis to Valkey. This simplifies the migration process as you don't need to update the application to accommodate new endpoints.