Merge pull request #66 from CS3219-AY2425S1/matching-logging-and-bug-fixing

Matching logging and bug fixing

Author: SPWwj

README.md

@@ -9,6 +9,17 @@ This project follows a microservices architecture with the following services:
 4. **Matching Service** - Port `3003`
 5. **MongoDB** - Port `27017` (Database)
 6. **Nginx API Gateway** - Port `80`
+7. **Redis** - Port `6379`
+
+### Setting up the Project
+Copy and paste the .env.example files in each service. Rename them as .env files.
+Files to do this in:
+1. ./
+2. /frontend
+3. /backend/user-service
+4. /backend/question-service
+5. /backend/matching-service
+Consult the readme files in the service if there are further configurations needed.
 
 ### Running the Project
 
@@ -23,6 +34,7 @@ Once the containers are up:
 - Matching Service: [http://localhost:3003](http://localhost:3003)
 - MongoDB: [http://localhost:27017](http://localhost:27017)
 - Nginx API Gateway: [http://localhost:80](http://localhost:80)
+- Redis: [http://localhost:6379](http://localhost:6379)
 
 ### MongoDB Configuration
 

backend/matching-service/.env.example

@@ -11,7 +11,7 @@ REDIS_PORT=6379
 # Matching time periods
 MATCHING_INTERVAL=1000
 RELAXATION_INTERVAL=3000
-MATCH_TIMEOUT=15000
+MATCH_TIMEOUT=30000
 CLEANUP_INTERVAL=75000
 
 # Copy root .env

backend/matching-service/README.md

@@ -1,17 +1,34 @@
-Hey, this is Nephelite again. 
+Matching service backend. 
 
-This service can be accessed both via REST API routes, and purely through websockets (via socket.Io). If you use REST, you must also send the client's socketId, so you need to retrieve it on the frontend first. If you are communicating purely via websockets, then you just need to send { username, email, category, difficulty } along with the event name of `startMatching`.
+To configure the .env files, create a copy of .env.example and rename it .env. 
+If you edited the .env file on the root level, copy and paste it in.
 
-To test the local implementation of this service without frontend, follow the steps below:
+.env variables:
+# Database Connection String Details
+DATABASE_NAME=peerprepMatchingServiceDB
+Should be the same as the root .env file.
 
-1. Run `npm install` at this level (root of matching-service).
-2. Configure the .env file. Edit the `DB_REQUIRE_AUTH` field in .env to be false for local.
-3. Successful match events will be recorded in MongoDB, under the Database `peerprepMatchingServiceDB` and `matchingevents` collection.
-4. Open 2 terminals: One to run the service, the other to run the test script.
-5. On either terminal: Open Docker, then run `docker pull redis:latest`, then `docker run --name redis-local -p 6379:6379 -d redis`.
-6. First terminal: Run `npm run dev`. Wait for the messages that the server is running and that it has successfully connected to MongoDB.
-7. Second terminal: Run `node testClientREST` or `node testClientEvent` and watch the tests go. The former uses the API calls, the latter uses exclusively the socket.io communication.
+# Port to run service on
+PORT=3003
+Port of the service.
 
-To add test cases, add them at the bottom of the testClient.js file.
+# Redis configuration
+REDIS_HOST=localhost
+REDIS_PORT=6379
+Redis uri configurations. Note: The port matters for all forms of deployment, but
+editing REDIS_HOST here only affects the local deployment. To affect the name of
+the redis uri, edit the docker-compose.yml file instead. This environment variable is
+overriden there.
 
-The testClient.js file also allows you to define delay as you wish, so you can use that to test your race condition prevention delay measures, though I also tried to ensure the implementation of matching here avoids race conditions as much as possible.
+# Matching time periods (In milliseconds)
+MATCHING_INTERVAL=1000
+The matching worker checks for matches for matches every ^ milliseconds.
+RELAXATION_INTERVAL=3000
+The matching worker relaxes requirements from users for matching every ^ milliseconds. 
+The first time ^ milliseconds passes, the users will be matched with only category considered.
+The second time ^ milliseconds passes, the users will be matched with only difficulty considered.
+At least one of category or difficulty must match.
+MATCH_TIMEOUT=30000
+Users will be considered as having timed out if the ^ milliseconds have passed.
+CLEANUP_INTERVAL=75000
+Stale users will be checked and cleansed every ^ milliseconds by the staleUserCleaner.

backend/matching-service/constants/queueTypes.ts

@@ -4,7 +4,6 @@ import { SOCKET_EVENTS } from "../constants/socketEventNames";
 import { MATCHING_STATUS } from "../constants/matchingStatus";
 import redisClient, { createRedisClient, logAllQueues } from "../utils/redisClient";
 import { decodeToken } from "../utils/tokenUtils";
-import Room from "../models/RoomSchema";
 
 import { startStaleUserCleanup } from '../workers/staleUserCleaner';
 import { isValidSocketId } from "../utils/helpers";
@@ -97,7 +96,6 @@ export function setupSocketListeners() {
 
             const token = socket.handshake.auth?.token;
 
-            // Use the decodeToken utility to decode the token
             const decodedToken = decodeToken(token);
             if (!decodedToken) {
                 socket.emit('error', { message: 'Invalid or missing token' });
@@ -107,7 +105,6 @@ export function setupSocketListeners() {
             const userId = decodedToken.id;
             console.log(`User connected: ${socket.id}, User ID: ${userId}`);
 
-            // Save user ID with socket ID in Redis only on connect
             const userData = {
                 userId,
                 socketId: socket.id,
@@ -116,7 +113,6 @@ export function setupSocketListeners() {
                 difficulty: difficulty,
             };
             redisClient.hSet(userKey, userData);
-            // Log the saved user data
             console.log('User data saved:', { userKey, userData });
 
             await redisClient.zAdd('matching_queue', {
@@ -143,7 +139,6 @@ export function setupSocketListeners() {
             console.log(`User disconnected: ${socketId}`);
             const userKey = `user:${socketId}`;
 
-            // Remove user from queue and delete data
             await redisClient.zRem('matching_queue', userKey);
             await redisClient.del(userKey);
         });
@@ -157,9 +152,8 @@ export async function setupSubscriber() {
 
     const streamKey = 'match_events';
     const consumerGroup = 'match_consumers';
-    const consumerName = `consumer_${process.pid}`; // Unique consumer name
+    const consumerName = `consumer_${process.pid}`;
 
-    // Create the consumer group if it doesn't exist
     try {
         await redisClientInstance.xGroupCreate(streamKey, consumerGroup, '0', { MKSTREAM: true });
         console.log(`Consumer group '${consumerGroup}' created.`);
@@ -171,10 +165,8 @@ export async function setupSubscriber() {
         }
     }
 
-    // Start processing messages
     processMatchEvents(redisClientInstance, streamKey, consumerGroup, consumerName);
 
-    // Start the periodic cleanup for stale users
     startStaleUserCleanup();
 }
 
@@ -210,17 +202,14 @@ async function processMatchEvents(
                         const id = message.id;
                         const fields = message.message;
 
-                        // Parse the match message
                         const user1 = JSON.parse(fields.user1);
                         const user2 = JSON.parse(fields.user2);
                         const roomId = fields.roomId;
                         const matchId = fields.matchId;
 
-                        // Log the message being processed
                         console.log(`Processing MatchEvent ID: ${matchId} from Stream ID: ${id}`);
                         console.log("Match Message Details:", { user1, user2, roomId, matchId });
 
-                        // Handle the match event
                         await handleMatchEvent(user1, user2, roomId, matchId);
                         await redisClient.xAck(streamKey, consumerGroup, id);
                         await redisClient.xDel(streamKey, id);
@@ -234,12 +223,10 @@ async function processMatchEvents(
     }
 }
 
-// Handle match event function
 async function handleMatchEvent(user1: any, user2: any, roomId: string, matchId: string) {
     try {
         const io = getSocket();
 
-        // Log the state of the message queue before processing the match event
         console.log("Before processing messages, message queue state:");
         const messagesBefore = await redisClient.xRange('match_events', '-', '+', { COUNT: 10 });
         console.log(messagesBefore);
@@ -248,11 +235,9 @@ async function handleMatchEvent(user1: any, user2: any, roomId: string, matchId:
         const socket2 = io.sockets.sockets.get(user2.socketId);
 
         if (socket1 && socket2) {
-            // Both users join the newly created room
             socket1.join(roomId);
             socket2.join(roomId);
 
-            // Emit match found event to both users with match details, including roomId and userId
             socket1.emit(SOCKET_EVENTS.MATCH_FOUND, {
                 message: `You have been matched with User ID: ${user2.userId}`,
                 category: user1.category || user2.category || 'Any',