Caffeine vs Memcached

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.

Memcached is a free, self-hosted in-memory key-value cache for reducing database load in dynamic web applications. It keeps small chunks of arbitrary data, such as strings, objects, and results from database calls, API calls, or page rendering. Clients use key-based hashing to choose a server, while servers operate independently without synchronization or replication. Items can expire after a specified time, and the default eviction policy is least recently used (LRU). The project describes Memcached as a developer tool, not code acceleration software or database middleware. Its API is available for most popular languages, and downloads include a source tarball and installation instructions with package prerequisites for Debian/Ubuntu and Red Hat/CentOS. TLS authentication and encryption are supported in version 1.5.13 and later when built with TLS and used with a TLS-capable client. Optional extstore moves values to external storage while keeping keys and the hash table in memory; it needs version 1.6.0 or newer. The project began in 2003. It is free and self-hosted, with no hosted plan or price listed.