ElastiCache vs OCI Cache for Valkey: size beyond the dataset

ElastiCache for Valkey fits teams choosing between automatic Serverless scaling and provisioned nodes on AWS. OCI Cache brings managed Valkey to Oracle Cloud, where bandwidth tied to memory and a 40,000-connection budget per node make capacity planning especially important. Cloud placement is the first decision. Then size for traffic and client connections as well as the dataset, with regional recovery responsibilities in view.

At a glance

About Amazon ElastiCache

Amazon ElastiCache is an AWS-managed caching service with Serverless and node-based deployment options. ElastiCache for Valkey runs the Valkey engine, while Redis OSS is a related offering. AWS manages infrastructure maintenance. Customers choose the deployment model and, for node-based clusters, the capacity and topology.

About OCI Cache

OCI Cache is Oracle’s managed caching service in Oracle Cloud Infrastructure. It supports Valkey and Redis, with sharded and non-sharded deployments. Customers configure memory, nodes, and sharding, and applications connect through private endpoints using supported network routing.

Recent updates

September 9, 2026 - OCI added cross-region replication. Regional recovery is now an option for non-sharded clusters in selected region pairs, with active-passive replication and customer promotion and rerouting. If regional recovery drives the purchase, evaluate those restrictions alongside the sharding and capacity plan rather than assuming every OCI cluster can use it.

September 2, 2026 - Momento introduced Cluster and Flex capacity for Momento Cache. Both provide dedicated, managed Valkey resources. Cluster exposes topology choices, while Flex selects topology within capacity bounds, giving teams a choice in how they configure capacity while Momento operates the cluster.

Size for traffic and client connections

OCI’s memory-linked bandwidth means a dataset that fits in RAM can still need more capacity to serve its traffic. You choose memory per node, node counts, and sharding, so throughput belongs in the sizing decision from the start.

Large application fleets also need a connection budget. Oracle documents up to 40,000 client connections per node and warns that excessive concurrency can increase latency. How connections spread across nodes matters as much as the fleet’s total.

ElastiCache Serverless scales automatically, and node-based deployments offer autoscaling options. Large scheduled events still deserve preparation. If anticipated demand exceeds Serverless scaling pace, AWS recommends pre-scaling at least 60 minutes ahead.

Plan regional recovery separately from local availability

ElastiCache Serverless has a 99.99% SLA. Node-based Valkey qualifies with automatic failover and placement of the primary and replicas across at least two availability zones per shard. OCI publishes a 99.95% monthly availability commitment.

OCI’s cross-region replication adds a regional recovery option, but your team promotes the secondary and redirects applications. Replication is asynchronous and active-passive, so recent unreplicated writes may be lost. It supports selected region pairs and non-sharded clusters with at least 8 GB per node. Participating clusters cannot use backups. Those constraints matter when choosing between a sharded deployment and a regional recovery design.

Try Momento Cache

If client growth is driving capacity choices, consider Momento for its managed connection layer and stable standalone-mode access.

Momento Cache puts dedicated, high-performance Valkey behind a managed gateway that keeps client integration stable as your application grows. Choose Cluster for direct control over instance types, shards, and replicas, or Flex to set capacity and replication bounds while Momento selects the topology. Both include built-in autoscaling and fully managed cluster operations.

Talk to a Momento solution engineer to evaluate the capacity model and configuration that fit your workload.

Frequently asked questions

How does maximum cache size compare?

ElastiCache falls in the 50 TB+ range, while OCI Cache’s calculated maximum rounds to 50 TB. Include long-term dataset growth alongside bandwidth and connection requirements when choosing a service.

Can applications outside the cloud connect?

Both services require a supported private network path. ElastiCache supports external connectivity, including documented VPN arrangements. OCI requires suitable private VCN routing. A device fleet therefore needs that network access as well as enough connections.

What technical support is available?

OCI offers support response from 15 minutes. AWS offers support response from 5 minutes, and existing account coverage may apply.