Cloudflare introduces Workers KV Instant powered by Quicksilver

Cloudflare has introduced Workers KV Instant, a new mode for its key-value store that leverages the internal Quicksilver infrastructure to provide instant global availability without cold read penalties. While Quicksilver has powered Cloudflare’s internal operations since 2020, this is the first time it is exposed to customers via the familiar Workers KV API.

Performance and Architecture

KV Instant is designed for data that is written occasionally but read frequently, such as application configuration and feature flags. By using Quicksilver v2, the service achieves read latencies under 2 milliseconds at the 99th percentile (p99), which is over 100 times faster than the classic Workers KV mode. Writes are replicated to the edge in approximately 250ms for 99% of operations, eliminating the need to wait for TTL expiration.

API Differences and Limitations

The service uses the same get(), put(), list(), and delete() methods as classic Workers KV, but with three key constraints:

• Mode Specification: Users must specify "mode": "instant" when creating a namespace.
• No Metadata: getWithMetadata calls return null, and metadata cannot be passed in put operations.
• No Pagination: list operations return all matching keys in a namespace without pagination.

Additionally, write frequency is restricted to one write per namespace per second to maintain consistency across the single system of record.

Pricing Structure

KV Instant is optimized for read-heavy workloads with small data footprints. Read operations (Class B) cost $0.20 per million, which is 60% less than classic Workers KV. However, storage and write operations are significantly more expensive:

• Storage: $100 per MB, per month (namespaces are limited to 1 MB total size).
• Class A Operations (put, delete, list): $0.10 per operation.

Availability

Workers KV Instant is currently in private beta. Cloudflare plans to open it to a wider audience after gathering initial customer feedback.