tokio-troubleshooting

Deadlocks in Tokio occur when tasks wait on each other indefinitely or hold locks across await points. Use tokio-console to observe task states and poll durations, then refactor to avoid lock-holding across awaits and ensure proper task cancellation on shutdown.

tokio-console is a real-time debugging tool that displays task metrics, spawn rates, and resource usage for Tokio applications. Add console-subscriber to Cargo.toml, initialize it before the runtime, then connect the UI to observe live metrics and identify bottlenecks.

Memory leaks in async code stem from task leaks, improper shutdowns, or cyclic references. Use tokio-console to track task counts and tracing to log resource allocation, then audit drop implementations and ensure graceful shutdown closes all spawned tasks.

Yes, tokio-console works with multi-threaded Tokio runtimes and displays metrics across all worker threads. It captures task scheduling, contention, and runtime behavior across the entire thread pool, enabling diagnosis of cross-thread performance issues.

Profile using tokio-console to measure task poll durations and scheduling latency across your runtime. Identify high-poll-duration tasks, reduce blocking work in async contexts, and tune the thread pool size to minimize jitter and contention.

Minimal changes are required: add console-subscriber as a dependency and call console_subscriber::init() at startup before constructing the runtime. No core business logic changes are needed; the subscriber runs in the background.