refactor(core): Include self-sending and debouncing in pubsub commands (#11149)

packages/cli/src/scaling/__tests__/publisher.service.test.ts

@@ -52,7 +52,7 @@ describe('Publisher', () => {
 
 			expect(client.publish).toHaveBeenCalledWith(
 				'n8n.commands',
-				JSON.stringify({ ...msg, senderId: queueModeId }),
+				JSON.stringify({ ...msg, senderId: queueModeId, selfSend: false, debounce: true }),
 			);
 		});
 	});

packages/cli/src/scaling/constants.ts

@@ -7,3 +7,17 @@ export const COMMAND_PUBSUB_CHANNEL = 'n8n.commands';
 
 /** Pubsub channel for messages sent by workers in response to commands from main processes. */
 export const WORKER_RESPONSE_PUBSUB_CHANNEL = 'n8n.worker-response';
+
+/**
+ * Commands that should be sent to the sender as well, e.g. during workflow activation and
+ * deactivation in multi-main setup. */
+export const SELF_SEND_COMMANDS = new Set([
+	'add-webhooks-triggers-and-pollers',
+	'remove-triggers-and-pollers',
+]);
+
+/**
+ * Commands that should not be debounced when received, e.g. during webhook handling in
+ * multi-main setup.
+ */
+export const IMMEDIATE_COMMANDS = new Set(['relay-execution-lifecycle-event']);

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

@@ -6,6 +6,7 @@ import { Logger } from '@/logging/logger.service';
 import { RedisClientService } from '@/services/redis-client.service';
 
 import type { PubSub } from './pubsub.types';
+import { IMMEDIATE_COMMANDS, SELF_SEND_COMMANDS } from '../constants';
 
 /**
  * Responsible for publishing messages into the pubsub channels used by scaling mode.
@@ -43,7 +44,12 @@ export class Publisher {
 	async publishCommand(msg: Omit<PubSub.Command, 'senderId'>) {
 		await this.client.publish(
 			'n8n.commands',
-			JSON.stringify({ ...msg, senderId: config.getEnv('redis.queueModeId') }),
+			JSON.stringify({
+				...msg,
+				senderId: config.getEnv('redis.queueModeId'),
+				selfSend: SELF_SEND_COMMANDS.has(msg.command),
+				debounce: !IMMEDIATE_COMMANDS.has(msg.command),
+			}),
 		);
 
 		this.logger.debug(`Published ${msg.command} to command channel`);

packages/cli/src/scaling/pubsub/pubsub.types.ts

@@ -22,6 +22,12 @@ export namespace PubSub {
 		senderId: string;
 		targets?: string[];
 		command: CommandKey;
+
+		/** Whether the command should be sent to the sender as well. */
+		selfSend?: boolean;
+
+		/** Whether the command should be debounced when received. */
+		debounce?: boolean;
 	} & (PubSubCommandMap[CommandKey] extends never
 		? { payload?: never } // some commands carry no payload
 		: { payload: PubSubCommandMap[CommandKey] });

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

@@ -70,12 +70,15 @@ export class Subscriber {
 	// #region Commands
 
 	setCommandMessageHandler() {
-		const handlerFn = debounce((str: string) => {
+		const handlerFn = (msg: PubSub.Command) => this.eventService.emit(msg.command, msg.payload);
-			const msg = this.parseCommandMessage(str);
+		const debouncedHandlerFn = debounce(handlerFn, 300);
-			if (msg) this.eventService.emit(msg.command, msg.payload);
-		}, 300);
 
-		this.setMessageHandler('n8n.commands', handlerFn);
+		this.setMessageHandler('n8n.commands', (str: string) => {
+			const msg = this.parseCommandMessage(str);
+			if (!msg) return;
+			if (msg.debounce) debouncedHandlerFn(msg);
+			else handlerFn(msg);
+		});
 	}
 
 	private parseCommandMessage(str: string) {
@@ -91,7 +94,10 @@ export class Subscriber {
 
 		const queueModeId = config.getEnv('redis.queueModeId');
 
-		if (msg.senderId === queueModeId || (msg.targets && !msg.targets.includes(queueModeId))) {
+		if (
+			!msg.selfSend &&
+			(msg.senderId === queueModeId || (msg.targets && !msg.targets.includes(queueModeId)))
+		) {
 			this.logger.debug('Disregarding message - not for this instance', msg);
 
 			return null;

packages/cli/src/services/orchestration/main/handle-command-message-main.ts

@@ -27,17 +27,11 @@ export async function handleCommandMessageMain(messageString: string) {
 			`RedisCommandHandler(main): Received command message ${message.command} from ${message.senderId}`,
 		);
 
-		const selfSendingAllowed = [
-			'add-webhooks-triggers-and-pollers',
-			'remove-triggers-and-pollers',
-		].includes(message.command);
-
 		if (
-			!selfSendingAllowed &&
+			!message.selfSend &&
 			(message.senderId === queueModeId ||
 				(message.targets && !message.targets.includes(queueModeId)))
 		) {
-			// Skipping command message because it's not for this instance
 			logger.debug(
 				`Skipping command message ${message.command} because it's not for this instance.`,
 			);