Ristretto

What Ristretto is

Ristretto is a free, open-source Go library for an in-process cache of key-value data. It is designed for performance, correctness, and concurrent use, with cache data held in memory within a single process rather than distributed across processes. TinyLFU admission and SampledLFU eviction are used to target high hit ratios. Applications define item costs, allowing one valuable large item to displace several smaller ones. The project attributes throughput to contention management, batching, and eventual consistency; it also says goroutines can use the cache concurrently with little throughput degradation. Optional metrics cover throughput, hit ratios, and other statistics. A Set for a new item may be dropped in the Set buffer or admission policy, while updates are guaranteed. Ristretto requires Go 1.21 or later and Go modules. Version 2 supports generics, and the project recommends it for new programs. The repository uses the Apache License, Version 2.0, and describes Ristretto as production-ready. Its README names Badger and Dgraph as users of the library.