Linux extreme performance H1 load generator (gcannon.org)

Glass Cannon is a Linux-only HTTP/1.1 and WebSocket load generator built on io_uring that targets high request throughput from a single machine while tracking per-request latency. It supports a TUI for live progress and a JSON mode for scripting/CI, and reports exact latency percentiles (including p99.9) using microsecond-resolution histogram sampling rather than estimates. The tool requires Linux 6.1+ and can measure latency at different stages (e.g., after response parse or at io_uring completion), with configurable concurrency, pipeline depth, and request counts per connection.