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rust.tokio.missing_runtime_config

Performance Medium

Detects Tokio runtime without proper configuration for production workloads.

Why It Matters

Unconfigured runtime:

Default thread count - May not match workload
No thread naming - Harder to debug
Missing tuning - Suboptimal performance

Example

// ❌ Before (default runtime)
#[tokio::main]
async fn main() {
    run_server().await;
}

// ✅ After (configured runtime)
use tokio::runtime::Builder;

fn main() {
    let runtime = Builder::new_multi_thread()
        .worker_threads(4)
        .thread_name("api-worker")
        .enable_all()
        .build()
        .unwrap();

    runtime.block_on(async {
        run_server().await;
    });
}

// Or with macro configuration:
#[tokio::main(flavor = "multi_thread", worker_threads = 4)]
async fn main() {
    run_server().await;
}

What Unfault Detects

Default #[tokio::main] without configuration
Missing worker_threads specification
No thread naming for debugging

Auto-Fix

Unfault can add explicit runtime configuration.