Caffeine vs Garnet

Caffeine is a free, open-source in-memory caching library for Java, distributed under the Apache License, Version 2.0. It provides an API inspired by Google Guava and can load entries automatically, including asynchronously. Size-based eviction uses configured limits with frequency and recency, while entries can expire according to time since their last access or write. When a stale entry is first requested, Caffeine can refresh it asynchronously. Other functions include weak keys, weak or soft values, removal notifications, writes to external resources, and cache statistics. The project offers JSR-107 JCache, Guava adapters, and a simulation extension, with community integrations listed for Spring Cache, Play Framework, Micronaut, Quarkus, and Apache Camel. The project directs users to Maven Central and provides Gradle coordinates for the core library and optional extensions. Version 3.x is intended for Java 11 or newer; earlier Java versions use 2.x. Maven Central artifacts are accompanied by GPG and Sigstore signature files according to the security policy.

Garnet is a free remote cache-store from Microsoft Research for self-hosted use on Linux, macOS, and Windows. It uses RESP and works with many unmodified Redis clients, including StackExchange.Redis; documented libraries also include Jedis, Redisson, redis-py, node_redis, and go-redis. Its data APIs cover strings, lists, hashes, sets, sorted sets, geo operations, HyperLogLog, bitmaps, ACLs, pub/sub, transactions, and Lua scripting. Garnet can store datasets larger than memory on local or cloud storage and supports checkpointing and recovery. Multi-node mode provides sharding, state migration, and replication. Developers can register C# data structures and read-modify-write operations through its custom operator framework. TLS/SSL and password-based RESP authentication are supported. DiskANN vector database support and Bf-Tree range indexes are marked preview. Garnet is MIT-licensed, but is not intended as a fully compatible Redis replacement and does not support Redis modules. The self-hosted plan is free; you manage infrastructure, updates, and operations. The managed Azure Cosmos DB Garnet Cache is in expanded Private Preview, with no price listed.