refactor(core): Separate listeners in scaling service (no-changelog) (#10487)

packages/cli/src/scaling/scaling.service.ts

@@ -13,11 +13,11 @@ import type {
 	Job,
 	JobData,
 	JobOptions,
-	JobMessage,
 	JobStatus,
 	JobId,
 	QueueRecoveryContext,
-} from './types';
+	PubSubMessage,
+} from './scaling.types';
 import type { IExecuteResponsePromiseData } from 'n8n-workflow';
 import { GlobalConfig } from '@n8n/config';
 import { ExecutionRepository } from '@/databases/repositories/execution.repository';
@@ -71,6 +71,7 @@ export class ScalingService {
 
 	setupWorker(concurrency: number) {
 		this.assertWorker();
+		this.assertQueue();
 
 		void this.queue.process(
 			JOB_TYPE_NAME,
@@ -161,22 +162,6 @@ export class ScalingService {
 	// #region Listeners
 
 	private registerListeners() {
-		this.queue.on('global:progress', (_jobId: JobId, msg: JobMessage) => {
-			if (msg.kind === 'respond-to-webhook') {
-				const { executionId, response } = msg;
-				this.activeExecutions.resolveResponsePromise(
-					executionId,
-					this.decodeWebhookResponse(response),
-				);
-			}
-		});
-
-		this.queue.on('global:progress', (jobId: JobId, msg: JobMessage) => {
-			if (msg.kind === 'abort-job') {
-				this.jobProcessor.stopJob(jobId);
-			}
-		});
-
 		let latestAttemptTs = 0;
 		let cumulativeTimeoutMs = 0;
 
@@ -210,10 +195,28 @@ export class ScalingService {
 				return;
 			}
 
-			if (
-				this.instanceType === 'worker' &&
-				error.message.includes('job stalled more than maxStalledCount')
-			) {
+			throw error;
+		});
+
+		if (this.instanceType === 'main') {
+			this.registerMainListeners();
+		} else if (this.instanceType === 'worker') {
+			this.registerWorkerListeners();
+		}
+	}
+
+	/**
+	 * Register listeners on a `worker` process for Bull queue events.
+	 */
+	private registerWorkerListeners() {
+		this.queue.on('global:progress', (jobId: JobId, msg: unknown) => {
+			if (!this.isPubSubMessage(msg)) return;
+
+			if (msg.kind === 'abort-job') this.jobProcessor.stopJob(jobId);
+		});
+
+		this.queue.on('error', (error: Error) => {
+			if (error.message.includes('job stalled more than maxStalledCount')) {
 				throw new MaxStalledCountError(error);
 			}
 
@@ -221,10 +224,7 @@ export class ScalingService {
 			 * Non-recoverable error on worker start with Redis unavailable.
 			 * Even if Redis recovers, worker will remain unable to process jobs.
 			 */
-			if (
-				this.instanceType === 'worker' &&
-				error.message.includes('Error initializing Lua scripts')
-			) {
+			if (error.message.includes('Error initializing Lua scripts')) {
 				this.logger.error('[ScalingService] Fatal error initializing worker', { error });
 				this.logger.error('[ScalingService] Exiting process...');
 				process.exit(1);
@@ -234,6 +234,24 @@ export class ScalingService {
 		});
 	}
 
+	/**
+	 * Register listeners on a `main` process for Bull queue events.
+	 */
+	private registerMainListeners() {
+		this.queue.on('global:progress', (_jobId: JobId, msg: unknown) => {
+			if (!this.isPubSubMessage(msg)) return;
+
+			if (msg.kind === 'respond-to-webhook') {
+				const decodedResponse = this.decodeWebhookResponse(msg.response);
+				this.activeExecutions.resolveResponsePromise(msg.executionId, decodedResponse);
+			}
+		});
+	}
+
+	private isPubSubMessage(candidate: unknown): candidate is PubSubMessage {
+		return typeof candidate === 'object' && candidate !== null && 'kind' in candidate;
+	}
+
 	// #endregion
 
 	private decodeWebhookResponse(
@@ -252,6 +270,12 @@ export class ScalingService {
 		return response;
 	}
 
+	private assertQueue() {
+		if (this.queue) return;
+
+		throw new ApplicationError('This method must be called after `setupQueue`');
+	}
+
 	private assertWorker() {
 		if (this.instanceType === 'worker') return;
 
@@ -265,7 +289,7 @@ export class ScalingService {
 		waitMs: config.getEnv('executions.queueRecovery.interval') * 60 * 1000,
 	};
 
-	scheduleQueueRecovery(waitMs = this.queueRecoveryContext.waitMs) {
+	private scheduleQueueRecovery(waitMs = this.queueRecoveryContext.waitMs) {
 		this.queueRecoveryContext.timeout = setTimeout(async () => {
 			try {
 				const nextWaitMs = await this.recoverFromQueue();
@@ -285,7 +309,7 @@ export class ScalingService {
 		this.logger.debug(`[ScalingService] Scheduled queue recovery check for next ${wait}`);
 	}
 
-	stopQueueRecovery() {
+	private stopQueueRecovery() {
 		clearTimeout(this.queueRecoveryContext.timeout);
 	}