Amazon ElastiCache vs Caffeine

Amazon ElastiCache is a managed caching service compatible with Valkey, Memcached, and Redis OSS, with performance described as microsecond latency. Customers can deploy a serverless cache or a node-based cluster. ElastiCache Serverless monitors compute, memory, and network use and scales vertically and horizontally as demand changes. It replicates data across multiple Availability Zones and offers a 99.99% availability SLA for each cache. Listed uses include application and semantic caching, data and session stores, and leaderboards. It can act as a front-end cache for Amazon RDS, Aurora, DocumentDB, and DynamoDB, and improve performance with EC2 and EMR. Security options include encryption in transit and at rest, IAM authentication, Valkey or Redis OSS AUTH, and role-based access control. CloudWatch provides more than 40 operational metrics at no additional charge. Valkey serverless pricing starts at $6 a month, billed according to stored data in GB-hours and requests measured in ECPUs. Data tiering is unavailable with ElastiCache Serverless.

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.