Function execution took 540029 ms, finished with status: 'timeout' - node.js

Question

I have created a cloud function that connects to an MQTT broker I have used a third-party MQTT broker (Mosquito MQTT broker), and sends the data to the Firebase real-time database every time the MQTT broker receives data from the machine. I am using the GCP console for writing and deploying the function. I successfully deployed the function without any errors, however, when I test it from the GCP console, it starts sending data but stops after the time specified in the timeout. I have tried timeout values from 60 to 540 seconds, but it still stops after the specified time. I have also increased the allocated memory, but it hasn't resolved the issue and I keep getting the same timeout error.
This is my code
const Admin = require("firebase-admin");
const functions = require("firebase-functions");
const mqtt = require('mqtt');
const clientId = 'mqtt_googleserver_********7'
const topic = '#'
const serviceAccount = require("./service.json");
Admin.initializeApp({
credential: Admin.credential.cert(serviceAccount),
databaseURL: "https://***************firebaseio.com/"
});
exports.rtdb_mains = functions.https.onRequest((_request, _response) => {
const client = mqtt.connect('mqtt://**.**.**.****.***',{
clientId,
clean: true,
connectTimeout: 4000,
username: '******',
password: '********',
reconnectPeriod: 1000,
});
const db = Admin.database();
client.addListener('connect', () => {
console.log('Connected');
client.subscribe([topic], { qos: 1 });
console.log(`Subscribe to topic '${topic}'`);
});
client.on('message', async (topic, payload) => {
console.log('Received Message:', topic, payload.toString());
if (payload.toString() !== "" && topic !== "") {
const ref = db.ref("All_machines");
const childref = ref.child(topic.toString());
await childref.set(payload.toString());
const topicDetails = topic.split("/");
const machineId = topicDetails[1];
const machineParameter = topicDetails[2];
if (machineParameter === "BoardID") {
const ref = db.ref(machineParameter);
await ref.set(machineId);
}
}
});
});
can anyone please help me with this problem.

Answer 1

You don't need to specify a service.json if you push the CF on firebase. You can directly use the default configuration.
You can do directly this :
admin.initializeApp();
Secondly, the way you use your MQTT implementation and the cloud function are not correct.
You are listenning and waiting for a message in a function that is trigger only by a POST or GET request.
I suggest to use the pub/sub api for doing such a thing and have a good implementation for sending / receiving messages.
In case of you really need to listen for message in your MQTT implementation, you will need another provider than Cloud Function or calling the native MQTT of Cloud Function
https://cloud.google.com/functions/docs/calling/pubsub
https://www.googlecloudcommunity.com/gc/Serverless/Can-a-cloud-function-subscribe-to-an-MQTT-topic/m-p/402965