firebase functions cold start use Express.js node.js get problem

System on firebase functions always have problems that code start.

https://medium.com/@siriwatknp/cold-start-workaround-in-firebase-cloud-functions-8e9db1426bd3

So

google office

https://firebase.google.com/docs/functions/networking

const http = require('http');
const functions = require('firebase-functions');

// Setting the `keepAlive` option to `true` keeps
// connections open between function invocations
const agent = new http.Agent({keepAlive: true});

exports.function = functions.https.onRequest((request, response) => {
    req = http.request({
        host: '',
        port: 80,
        path: '',
        method: 'GET',
        agent: agent, // Holds the connection open after the first invocation
    }, res => {
        let rawData = '';
        res.setEncoding('utf8');
        res.on('data', chunk => { rawData += chunk; });
...

Two line let me confused. Not only me.

const agent = new http.Agent({keepAlive: true}); 

agent: agent, // Holds the connection open after the first invocation

Some guy same me.

Get same problem.

https://stackoverflow.com/questions/56912118/how-can-i-maintain-persist-a-cloud-functions-connection-using-expressjs

Success??

https://stackoverflow.com/questions/55425015/how-to-keep-alive-dialogflow-firebase-function-to-avoid-new-connection-time-wast

Thanks Max. However I found the answer to this problem from the same link I posted above (i.e. firebase.google.com/docs/functions/networking). Just adding two lines of code solved the problem. Now response is quite prompt. I added following lines: 1. const agent = new http.Agent({keepAlive: true}); 2. agent: agent, – Vipul Sisodia Apr 2 '19 at 19:04

See Express.js

https://nodejs.org/dist/latest-v10.x/docs/api/http.html#http_new_agent_options

Not thing can Try.

Other way

https://medium.com/@onufrienkos/keep-alive-connection-on-inter-service-http-requests-3f2de73ffa1

https://stackoverflow.com/questions/60667847/unable-to-verify-leaf-signature-from-request-with-firebase-functions-node-js-wit

index.js

require('https').globalAgent.keepAlive = true;

const functions = require('firebase-functions');
const express = require('express');
const app = express();

...

exports.api = functions.runWith(runtimeOpts).https.onRequest(app);

require('https').globalAgent.keepAlive = true;

Try by yourself.