AWS Glossary
Amazon MemoryDB for Valkey
MemoryDB for Valkey is an in-memory database compatible with the open-source Valkey engine (Redis 7.x fork) — durable, multi-AZ, with up to 65% lower cost vs MemoryDB for Redis OSS.
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Summary
MemoryDB for Valkey is an in-memory database compatible with the open-source Valkey engine (Redis 7.x fork) — durable, multi-AZ, with up to 65% lower cost vs MemoryDB for Redis OSS.
Key Facts
- • MemoryDB for Valkey is an in-memory database compatible with the open-source Valkey engine (Redis 7
- • x fork) — durable, multi-AZ, with up to 65% lower cost vs MemoryDB for Redis OSS
- • Definition Amazon MemoryDB for Valkey is a managed in-memory database service that runs the Valkey engine — the open-source, Linux Foundation-backed fork of Redis 7
- • Released in 2024 alongside ElastiCache for Valkey, MemoryDB for Valkey provides durable, multi-AZ, Redis-API-compatible storage for primary-database use cases (not just caching)
- • AWS prices it up to 65% below MemoryDB for Redis OSS
Entity Definitions
- S3
- S3 is an AWS service relevant to amazon memorydb for valkey.
- Aurora
- Aurora is an AWS service relevant to amazon memorydb for valkey.
- DynamoDB
- DynamoDB is an AWS service relevant to amazon memorydb for valkey.
- Amazon DynamoDB
- Amazon DynamoDB is an AWS service relevant to amazon memorydb for valkey.
- ElastiCache
- ElastiCache is an AWS service relevant to amazon memorydb for valkey.
- Amazon ElastiCache
- Amazon ElastiCache is an AWS service relevant to amazon memorydb for valkey.
- OpenSearch
- OpenSearch is an AWS service relevant to amazon memorydb for valkey.
- RAG
- RAG is a cloud computing concept relevant to amazon memorydb for valkey.
- serverless
- serverless is a cloud computing concept relevant to amazon memorydb for valkey.
Related Content
- AWS APPLICATION MODERNIZATION — Related service
- AWS SERVERLESS — Related service
Definition
Amazon MemoryDB for Valkey is a managed in-memory database service that runs the Valkey engine — the open-source, Linux Foundation-backed fork of Redis 7.x. Released in 2024 alongside ElastiCache for Valkey, MemoryDB for Valkey provides durable, multi-AZ, Redis-API-compatible storage for primary-database use cases (not just caching). AWS prices it up to 65% below MemoryDB for Redis OSS.
Why Valkey, not Redis OSS
Redis Inc. relicensed Redis OSS in 2024 under SSPL/RSALv2, ending OSI-compatible open-source status. The Linux Foundation forked the codebase as Valkey, with AWS, Google Cloud, Oracle, and major OSS contributors backing the fork. Valkey is wire-protocol and command compatible with Redis 7.x, with active development going forward.
MemoryDB vs ElastiCache
| Aspect | MemoryDB | ElastiCache |
|---|---|---|
| Use case | Primary database | Cache / sidekick to a primary DB |
| Durability | Multi-AZ transaction log | In-memory only by default |
| Latency | Single-digit ms reads, low-ms writes (with durability cost) | Sub-millisecond |
| Pricing | Higher per-GB | Lower per-GB |
| Engines | Valkey, Redis OSS | Valkey, Redis OSS, Memcached |
Capabilities
- Redis-API compatibility — Client drivers, ORM bindings, Lua scripts work unchanged
- Multi-AZ transaction log — Durable writes, no data loss on node failure
- Vector search — Built-in Valkey-Search module for vector similarity (alternative to OpenSearch / S3 Vectors for small-scale RAG)
- TLS, encryption at rest — Standard AWS controls
- Cluster mode — Horizontal scaling via sharding
When to use MemoryDB for Valkey
- Session stores, leaderboards, real-time gaming state as a primary database
- You need Redis API + durability + multi-AZ failover
- Migration off Redis OSS / ElastiCache for Redis to escape SSPL licensing
When not to use it
- Pure cache workload — ElastiCache for Valkey is cheaper and faster
- High-cardinality analytical queries — Use OpenSearch, Aurora, or DynamoDB
- Multi-region active-active — Use MemoryDB Global Datastore or DynamoDB Global Tables
Common mistakes
Mistake 1: Migrating from Redis OSS by point-in-time snapshot without replay validation. Use AWS DMS or RIOT for live replication and validation.
Mistake 2: Reusing Redis-OSS-specific commercial modules. Some Redis Inc. modules (RediSearch, RedisJSON v2) are not in Valkey. Validate module compatibility before migration.
Mistake 3: Sizing MemoryDB the same as ElastiCache. Durability writes add CPU overhead — provision 20–30% more than your read-throughput target.
Related AWS Services
- Amazon ElastiCache for Valkey — Cache use cases
- Amazon DynamoDB — Single-digit ms key-value alternative
- AWS DMS — Migration tooling
Related FactualMinds Content
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