Proxy server opens a new outbound TCP/HTTP connection per request (no reuse)

[ameba23]

This is a performance issue and a proposal to enhance performance / throughput.

Problem

ProxyServer::handle_http_request opens a fresh TcpStream::connect and performs a new Hyper HTTP/1.1 client handshake for every incoming request. This disables keep‑alive reuse and adds per‑request connection overhead (DNS resolution, TCP handshake, HTTP handshake).

• File: src/lib.rs
• Function: ProxyServer::handle_http_request

Impact

• Throughput is limited by connection setup rather than request handling.
• Higher latency under load.
• Increased CPU usage and ephemeral port churn.

Proposed fix

Introduce outbound connection reuse:

• Maintain a persistent HTTP client connection to the target service.
• Prefer HTTP/2 upstream when available to multiplex requests.
• Avoid TcpStream::connect per request.

Acceptance criteria

• Outbound connections are reused across multiple requests (observable via logs).
• Nice to have: throughput improves in a load test vs. current baseline.
• No regression in proxy correctness (headers, attestation metadata, error handling).

Notes

The current code creates the outbound connection here:

• src/lib.rs → ProxyServer::handle_http_request (TcpStream::connect, http1::Builder::handshake).