From 137193c3e908483ae1199aea7dbdee365b9e2e8f Mon Sep 17 00:00:00 2001
From: Tomi Turtiainen <10324676+tomi@users.noreply.github.com>
Date: Wed, 27 Nov 2024 10:36:37 +0200
Subject: [PATCH] fix(core): Increase task runner offer validity and introduce
 randomness (no-changelog) (#11907)

---
 packages/@n8n/task-runner/src/task-runner.ts | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/packages/@n8n/task-runner/src/task-runner.ts b/packages/@n8n/task-runner/src/task-runner.ts
index 8af8aeeb08..1486af280d 100644
--- a/packages/@n8n/task-runner/src/task-runner.ts
+++ b/packages/@n8n/task-runner/src/task-runner.ts
@@ -1,4 +1,4 @@
-import { ApplicationError, ensureError } from 'n8n-workflow';
+import { ApplicationError, ensureError, randomInt } from 'n8n-workflow';
 import { nanoid } from 'nanoid';
 import { EventEmitter } from 'node:events';
 import { type MessageEvent, WebSocket } from 'ws';
@@ -42,8 +42,11 @@ export interface RPCCallObject {
 	[name: string]: ((...args: unknown[]) => Promise<unknown>) | RPCCallObject;
 }
 
-const VALID_TIME_MS = 1000;
-const VALID_EXTRA_MS = 100;
+const OFFER_VALID_TIME_MS = 5000;
+const OFFER_VALID_EXTRA_MS = 100;
+
+/** Converts milliseconds to nanoseconds */
+const msToNs = (ms: number) => BigInt(ms * 1_000_000);
 
 export interface TaskRunnerOpts extends BaseRunnerConfig {
 	taskType: string;
@@ -167,16 +170,20 @@ export abstract class TaskRunner extends EventEmitter {
 			(Object.values(this.openOffers).length + Object.values(this.runningTasks).length);
 
 		for (let i = 0; i < offersToSend; i++) {
+			// Add a bit of randomness so that not all offers expire at the same time
+			const validForInMs = OFFER_VALID_TIME_MS + randomInt(500);
+			// Add a little extra time to account for latency
+			const validUntil = process.hrtime.bigint() + msToNs(validForInMs + OFFER_VALID_EXTRA_MS);
 			const offer: TaskOffer = {
 				offerId: nanoid(),
-				validUntil: process.hrtime.bigint() + BigInt((VALID_TIME_MS + VALID_EXTRA_MS) * 1_000_000), // Adding a little extra time to account for latency
+				validUntil,
 			};
 			this.openOffers.set(offer.offerId, offer);
 			this.send({
 				type: 'runner:taskoffer',
 				taskType: this.taskType,
 				offerId: offer.offerId,
-				validFor: VALID_TIME_MS,
+				validFor: validForInMs,
 			});
 		}
 	}