From 9eaca966a480fc2b0a3da503d413994c5bf0cbe0 Mon Sep 17 00:00:00 2001
From: syuilo <Syuilotan@yahoo.co.jp>
Date: Fri, 2 Jun 2023 09:13:41 +0900
Subject: [PATCH] perf(backend): terminate stalled websocket connections

Resolve #10885
---
 .../server/api/StreamingApiServerService.ts   | 23 +++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/packages/backend/src/server/api/StreamingApiServerService.ts b/packages/backend/src/server/api/StreamingApiServerService.ts
index fdda581ada..893dfe956e 100644
--- a/packages/backend/src/server/api/StreamingApiServerService.ts
+++ b/packages/backend/src/server/api/StreamingApiServerService.ts
@@ -19,6 +19,8 @@ import type * as http from 'node:http';
 @Injectable()
 export class StreamingApiServerService {
 	#wss: WebSocket.WebSocketServer;
+	#connections = new Map<WebSocket.WebSocket, number>();
+	#cleanConnectionsIntervalId: NodeJS.Timeout | null = null;
 
 	constructor(
 		@Inject(DI.config)
@@ -109,7 +111,9 @@ export class StreamingApiServerService {
 
 			await stream.listen(ev, connection);
 
-			const intervalId = user ? setInterval(() => {
+			this.#connections.set(connection, Date.now());
+
+			const userUpdateIntervalId = user ? setInterval(() => {
 				this.usersRepository.update(user.id, {
 					lastActiveDate: new Date(),
 				});
@@ -124,19 +128,34 @@ export class StreamingApiServerService {
 				ev.removeAllListeners();
 				stream.dispose();
 				this.redisForSub.off('message', onRedisMessage);
-				if (intervalId) clearInterval(intervalId);
+				if (userUpdateIntervalId) clearInterval(userUpdateIntervalId);
 			});
 
 			connection.on('message', async (data) => {
+				this.#connections.set(connection, Date.now());
 				if (data.toString() === 'ping') {
 					connection.send('pong');
 				}
 			});
 		});
+
+		this.#cleanConnectionsIntervalId = setInterval(() => {
+			const now = Date.now();
+			for (const [connection, lastActive] of this.#connections.entries()) {
+				if (now - lastActive > 1000 * 60 * 5) {
+					connection.terminate();
+					this.#connections.delete(connection);
+				}
+			}
+		}, 1000 * 60 * 5);
 	}
 
 	@bindThis
 	public detach(): Promise<void> {
+		if (this.#cleanConnectionsIntervalId) {
+			clearInterval(this.#cleanConnectionsIntervalId);
+			this.#cleanConnectionsIntervalId = null;
+		}
 		return new Promise((resolve) => {
 			this.#wss.close(() => resolve());
 		});