# Logging
Qrusty emits structured events via the `tracing` crate. The formatter writes to
stderr, and the same stream feeds the in-process log buffer that drives the
`/logs` WebSocket used by the web UI.
## Verbosity
Log filtering is controlled by the `RUST_LOG` environment variable using
[`EnvFilter`](https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html)
syntax. When unset, the default is `info`.
```bash
# Quiet down to warnings and above
RUST_LOG=warn qrusty
# Full debug across all modules
RUST_LOG=debug qrusty
# Debug only WebSocket internals; keep everything else at info
RUST_LOG=info,qrusty::ws=debug qrusty
```
## Debugging WebSocket performance
When investigating poor throughput with deep queues or many workers per queue,
raise the WS module to `debug`:
```bash
RUST_LOG=info,qrusty::ws=debug,qrusty_client::ws=debug qrusty
```
At that level you'll see per-connection events:
- Connection open and close, with uptime and subscription counts.
- Every ping send (`"ws: sending ping"`) and pong receipt.
- Ping-timeout closures with the actual elapsed time since the last pong.
- Router and sink-writer task exit reasons (stream EOF, stream error,
channel closed, client close frame code/reason).
- Client-side router frame counts at exit.
These events also stream through `/logs` in the web UI's Logs tab, filtered
by the same `RUST_LOG` directive.
## Module paths
- `qrusty::ws` — server-side WebSocket connection handler
- `qrusty::storage` — RocksDB storage engine
- `qrusty::api` — HTTP handlers
- `qrusty_client::ws` — client-side WebSocket router and sink tasks