Apache Traffic Server vs Ristretto

Apache Traffic Server is a free, open-source caching proxy server for HTTP/1.1 and HTTP/2. It stores frequently requested pages, images, and web service calls so they can be reused, with the stated aims of improving response time and reducing server load and bandwidth needs. It can also add keep-alive behavior, filter or anonymize requests, and balance traffic through a proxy layer. Deployment patterns include web proxy cache, reverse proxy, and cache hierarchy. As a layer 7 HTTP load balancer, it can choose next-hop servers using request attributes, weighted round robin, or URL consistent hashing. Plug-in APIs let teams add behavior such as changing headers, handling ESI requests, or implementing cache algorithms. Security options include client access controls and authentication, SSL termination, and SSL-based access control. It is self-hosted, with Linux and macOS listed as platforms. The project identifies enterprises, internet service providers, backbone providers, and large intranets as its intended audience. The listed stable release is 10.2.0; 9.2.15 is listed as the long-term support release.

Ristretto is a free, open-source Go library for an in-process cache of key-value data, designed for concurrent use, performance and correctness. It keeps data in memory in a single process rather than operating as a distributed cache. TinyLFU admission and SampledLFU eviction are paired to target high hit ratios; applications define item cost, allowing a valuable large item to displace several smaller ones. The project attributes throughput to contention management, batching and eventual consistency. Goroutines can use the cache concurrently with little throughput degradation, according to the project, and 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, which the project recommends for new programs. The repository is licensed under Apache License, Version 2.0, and describes the library as production-ready. Its README names Badger and Dgraph as projects using it.