From a12e782225fd5b106a2f7a713c2eafb5768f19a2 Mon Sep 17 00:00:00 2001
From: shortstacked <declan@n8n.io>
Date: Tue, 2 Sep 2025 18:30:49 +0100
Subject: [PATCH] test: Add baseline memory test (#19102)

---
 .../containers/n8n-test-container-creation.ts |  1 +
 .../testing/playwright/playwright.config.ts   |  2 +-
 .../memory-consumption-cloud.spec.ts          | 29 ++++++++++++++
 .../playwright/utils/performance-helper.ts    | 39 +++++++++++++++++++
 4 files changed, 70 insertions(+), 1 deletion(-)
 create mode 100644 packages/testing/playwright/tests/performance/memory-consumption-cloud.spec.ts

diff --git a/packages/testing/containers/n8n-test-container-creation.ts b/packages/testing/containers/n8n-test-container-creation.ts
index 952ba0c958..a8fe1e800d 100644
--- a/packages/testing/containers/n8n-test-container-creation.ts
+++ b/packages/testing/containers/n8n-test-container-creation.ts
@@ -42,6 +42,7 @@ const BASE_ENV: Record<string, string> = {
 	E2E_TESTS: 'false',
 	QUEUE_HEALTH_CHECK_ACTIVE: 'true',
 	N8N_DIAGNOSTICS_ENABLED: 'false',
+	N8N_METRICS: 'true',
 	N8N_RUNNERS_ENABLED: 'true',
 	NODE_ENV: 'development', // If this is set to test, the n8n container will not start, insights module is not found??
 	N8N_LICENSE_TENANT_ID: process.env.N8N_LICENSE_TENANT_ID ?? '1001',
diff --git a/packages/testing/playwright/playwright.config.ts b/packages/testing/playwright/playwright.config.ts
index 9740fee7c7..1a8e8ab7f3 100644
--- a/packages/testing/playwright/playwright.config.ts
+++ b/packages/testing/playwright/playwright.config.ts
@@ -71,5 +71,5 @@ export default defineConfig({
 				currentsReporter(currentsConfig),
 				['./reporters/metrics-reporter.ts'],
 			]
-		: [['html'], ['./reporters/metrics-reporter.ts']],
+		: [['html'], ['./reporters/metrics-reporter.ts'], ['list']],
 });
diff --git a/packages/testing/playwright/tests/performance/memory-consumption-cloud.spec.ts b/packages/testing/playwright/tests/performance/memory-consumption-cloud.spec.ts
new file mode 100644
index 0000000000..10a552965f
--- /dev/null
+++ b/packages/testing/playwright/tests/performance/memory-consumption-cloud.spec.ts
@@ -0,0 +1,29 @@
+import { test, expect } from '../../fixtures/cloud';
+import { attachMetric, pollMemoryMetric } from '../../utils/performance-helper';
+
+test.describe('Memory Consumption', () => {
+	const CONTAINER_STABILIZATION_TIME = 20000;
+	const POLL_MEMORY_DURATION = 30000;
+	const STARTER_PLAN_MEMORY_LIMIT = 768;
+
+	test('Memory consumption baseline with starter plan resources @cloud:starter', async ({
+		cloudContainer,
+	}, testInfo) => {
+		// Wait for container to stabilize
+		await new Promise((resolve) => setTimeout(resolve, CONTAINER_STABILIZATION_TIME));
+
+		// Poll memory metric for 30 seconds to get baseline
+		const averageMemoryBytes = await pollMemoryMetric(
+			cloudContainer.baseUrl,
+			POLL_MEMORY_DURATION,
+			1000,
+		);
+		const averageMemoryMB = averageMemoryBytes / 1024 / 1024;
+
+		await attachMetric(testInfo, 'memory-consumption-baseline', averageMemoryMB, 'MB');
+
+		// Verify memory is within starter plan limits (768MB)
+		expect(averageMemoryMB).toBeLessThan(STARTER_PLAN_MEMORY_LIMIT);
+		expect(averageMemoryMB).toBeGreaterThan(100);
+	});
+});
diff --git a/packages/testing/playwright/utils/performance-helper.ts b/packages/testing/playwright/utils/performance-helper.ts
index 1ce92c371b..5f66df1302 100644
--- a/packages/testing/playwright/utils/performance-helper.ts
+++ b/packages/testing/playwright/utils/performance-helper.ts
@@ -29,6 +29,45 @@ export async function getAllPerformanceMetrics(page: Page) {
 	});
 }
 
+/**
+ * Polls the memory metric from Prometheus endpoint and calculates average
+ * @param baseUrl - The base URL of the n8n instance
+ * @param durationMs - How long to poll in milliseconds
+ * @param intervalMs - Interval between polls in milliseconds
+ * @returns Average memory consumption in bytes
+ */
+export async function pollMemoryMetric(
+	baseUrl: string,
+	durationMs: number = 30000,
+	intervalMs: number = 1000,
+): Promise<number> {
+	const samples: number[] = [];
+	const startTime = Date.now();
+
+	while (Date.now() - startTime < durationMs) {
+		try {
+			const response = await fetch(`${baseUrl}/metrics`);
+			const metricsText = await response.text();
+
+			const memoryMatch = metricsText.match(/n8n_process_resident_memory_bytes\s+(\d+(?:\.\d+)?)/);
+			if (memoryMatch) {
+				const memoryBytes = parseFloat(memoryMatch[1]);
+				samples.push(memoryBytes);
+			}
+		} catch (error) {
+			console.error('Error polling memory metric:', error);
+		}
+
+		await new Promise((resolve) => setTimeout(resolve, intervalMs));
+	}
+
+	if (samples.length === 0) {
+		throw new Error('No memory samples collected');
+	}
+
+	return samples.reduce((sum, sample) => sum + sample, 0) / samples.length;
+}
+
 /**
  * Attach a performance metric for collection by the metrics reporter
  * @param testInfo - The Playwright TestInfo object