Performance & socket tuning

The proxy exposes the socket and connection knobs that matter under load. The defaults are tuned for low latency and high concurrency, so most deployments never change them — but when you are chasing tail latency or a very specific traffic shape, these are the levers.

• Latency — nodelay, proxy_nodelay, nonblocking keep small messages flowing without Nagle delay.
• Throughput — recv_buffer_size and send_buffer_size size the kernel socket buffers.
• Concurrency — max_backlog bounds the accept queue; proxy_keepalive_sec reuses upstream connections.
• Large/slow responses — enable_streaming streams bodies instead of buffering them.