Runtime diagnostics for leaked messages in unbounded channels (#12971)

substrate/client/service/src/builder.rs

@@ -962,7 +962,7 @@ where
 	);
 	spawn_handle.spawn("import-queue", None, import_queue.run(Box::new(chain_sync_service)));
 
-	let (system_rpc_tx, system_rpc_rx) = tracing_unbounded("mpsc_system_rpc");
+	let (system_rpc_tx, system_rpc_rx) = tracing_unbounded("mpsc_system_rpc", 10_000);
 
 	let future = build_network_future(
 		config.role.clone(),

substrate/client/service/src/client/client.rs

@@ -1913,13 +1913,13 @@ where
 {
 	/// Get block import event stream.
 	fn import_notification_stream(&self) -> ImportNotifications<Block> {
-		let (sink, stream) = tracing_unbounded("mpsc_import_notification_stream");
+		let (sink, stream) = tracing_unbounded("mpsc_import_notification_stream", 100_000);
 		self.import_notification_sinks.lock().push(sink);
 		stream
 	}
 
 	fn finality_notification_stream(&self) -> FinalityNotifications<Block> {
-		let (sink, stream) = tracing_unbounded("mpsc_finality_notification_stream");
+		let (sink, stream) = tracing_unbounded("mpsc_finality_notification_stream", 100_000);
 		self.finality_notification_sinks.lock().push(sink);
 		stream
 	}

substrate/client/service/src/task_manager/mod.rs

@@ -310,7 +310,8 @@ impl TaskManager {
 		let (signal, on_exit) = exit_future::signal();
 
 		// A side-channel for essential tasks to communicate shutdown.
-		let (essential_failed_tx, essential_failed_rx) = tracing_unbounded("mpsc_essential_tasks");
+		let (essential_failed_tx, essential_failed_rx) =
+			tracing_unbounded("mpsc_essential_tasks", 100);
 
 		let metrics = prometheus_registry.map(Metrics::register).transpose()?;