Git fetch performance improvements in 2021, Part 2

What this post added

This post details the technical implementation of the pack-objects cache for Git fetch requests, which deduplicates identical requests to reduce CPU and memory usage. It also describes the development of an improved RPC transport for Git HTTP traffic, utilizing side channels to bypass gRPC overhead and reduce CPU usage on Gitaly servers. The post highlights the challenges faced, such as increased disk write throughput with the cache and potential gRPC memory allocation overhead, and the solutions implemented.