enhance(dev): improve mem report (#17118)

* wip

* wip

* Update report-backend-memory.yml

* Update report-backend-memory.yml

* Update .github/workflows/report-backend-memory.yml

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

3 files changed, 38 insertions, 14 deletions

diff --git a/packages/backend/scripts/measure-memory.mjs b/packages/backend/scripts/measure-memory.mjs
index 82a5a0bf0b..749f550bcc 100644
--- a/packages/backend/scripts/measure-memory.mjs
+++ b/packages/backend/scripts/measure-memory.mjs
@@ -60,9 +60,9 @@ async function measureMemory() {
 			...process.env,
 			NODE_ENV: 'production',
 			MK_DISABLE_CLUSTERING: '1',
-			MK_FORCE_GC: '1',
 		},
 		stdio: ['pipe', 'pipe', 'pipe', 'ipc'],
+		execArgv: [...process.execArgv, '--expose-gc'],
 	});
 
 	let serverReady = false;
@@ -104,9 +104,21 @@ async function measureMemory() {
 	// Wait for memory to settle
 	await setTimeout(MEMORY_SETTLE_TIME);
 
-	// Get memory usage from the server process via /proc
 	const pid = serverProcess.pid;
-	const memoryInfo = await getMemoryUsage(pid);
+
+	const beforeGc = await getMemoryUsage(pid);
+
+	serverProcess.send('gc');
+
+	await new Promise((resolve) => {
+		serverProcess.once('message', (message) => {
+			if (message === 'gc ok') resolve();
+		});
+	});
+
+	await setTimeout(1000);
+
+	const afterGc = await getMemoryUsage(pid);
 
 	// Stop the server
 	serverProcess.kill('SIGTERM');
@@ -129,7 +141,8 @@ async function measureMemory() {
 
 	const result = {
 		timestamp: new Date().toISOString(),
-		memory: memoryInfo,
+		beforeGc,
+		afterGc,
 	};
 
 	return result;
@@ -144,19 +157,23 @@ async function main() {
 	}
 
 	// Calculate averages
-	const avgMemory = structuredClone(keys);
+	const beforeGc = structuredClone(keys);
+	const afterGc = structuredClone(keys);
 	for (const res of results) {
-		for (const key of Object.keys(avgMemory)) {
-			avgMemory[key] += res.memory[key];
+		for (const key of Object.keys(keys)) {
+			beforeGc[key] += res.beforeGc[key];
+			afterGc[key] += res.afterGc[key];
 		}
 	}
-	for (const key of Object.keys(avgMemory)) {
-		avgMemory[key] = Math.round(avgMemory[key] / SAMPLE_COUNT);
+	for (const key of Object.keys(keys)) {
+		beforeGc[key] = Math.round(beforeGc[key] / SAMPLE_COUNT);
+		afterGc[key] = Math.round(afterGc[key] / SAMPLE_COUNT);
 	}
 
 	const result = {
 		timestamp: new Date().toISOString(),
-		memory: avgMemory,
+		beforeGc,
+		afterGc,
 	};
 
 	// Output as JSON to stdout
diff --git a/packages/backend/src/boot/entry.ts b/packages/backend/src/boot/entry.ts
index 56b339b6aa..3a33d198a5 100644
--- a/packages/backend/src/boot/entry.ts
+++ b/packages/backend/src/boot/entry.ts
@@ -86,9 +86,17 @@ if (!envOption.disableClustering) {
 	ev.mount();
 }
 
-if (envOption.forceGc && global.gc != null) {
-	global.gc();
-}
+process.on('message', msg => {
+	if (msg === 'gc') {
+		if (global.gc != null) {
+			logger.info('Manual GC triggered');
+			global.gc();
+			if (process.send != null) process.send('gc ok');
+		} else {
+			logger.warn('Manual GC requested but gc is not available. Start the process with --expose-gc to enable this feature.');
+		}
+	}
+});
 
 readyRef.value = true;
 
diff --git a/packages/backend/src/env.ts b/packages/backend/src/env.ts
index 9957938467..ba44cfa2e6 100644
--- a/packages/backend/src/env.ts
+++ b/packages/backend/src/env.ts
@@ -11,7 +11,6 @@ const envOption = {
 	verbose: false,
 	withLogTime: false,
 	quiet: false,
-	forceGc: false,
 };
 
 for (const key of Object.keys(envOption) as (keyof typeof envOption)[]) {