Scaling memcached at Facebook

What this post added

This post details critical scaling challenges and solutions for memcached, Facebook's largest user of the system. It highlights modifications made to the operating system and memcached to address memory inefficiencies from per-connection buffers, improve UDP performance through per-thread sockets, distribute network I/O across cores with opportunistic polling, and resolve contention issues in stat collection and network transmit queues. These changes significantly boosted memcached's performance, enabling it to handle much higher request rates and lower latency, and led to the release of these modifications on GitHub.