Too many requests from nodejs server causes "connect EADDRNOTAVAIL"

Question

In my Node server (running on Mac), I'm requesting data from an external API using websockets and sending the result I get to my cloud API.

The websocket is sending a lot of data (1000+ obj/s). When I try to POST this to my cloud server, I get error on client side (my node server). This only happens during high load, I get no errors when load is lower (say 300/s). I'm not POSTing to my local server so I don't know what this error means.

One thing I noticed is that the ports are not reused. When I have high load, I go up to 15000+ used ports on my local machine and then I start getting these errors.

I have tried setting "agent: false" in the HTTP header without success. I have also tried "connection": "keep-alive" without success (found these two suggestions on SO).

This is the code that is POSTing the data I get from websocket:

function PostCode(codestring, apipathstring) {

    return new Promise((resolve,reject)=>{

        // An object of options to indicate where to post to
        var post_options = {
            host: 'hostname', //
            port: 'port',
            path: apipathstring,
            method: 'POST',
            headers: {
              'Content-Type': 'application/json',
              'Content-Length': Buffer.byteLength(post_data),
            }
        };

        // Set up the request
        var post_req = https.request(post_options,function(res){
            let data = '';
            res.setEncoding('utf8');

            // A chunk of data has been recieved.
            res.on('data', (chunk) => {
                data += chunk;
            });

            // The whole response has been received. Print out the result.
            res.on('end', () => {
                resolve(data);
            });

            // Error event received
            }).on("error", (err) => {
                reject("POSTING Error: " + err);    
            });

            post_req.write(post_data);
            post_req.end();
    })
}

Optimally, I would stream even high traffic data without getting these connection errors.

Errors below:

Error: connect EADDRNOTAVAIL [my_cloud_IP] - Local (0.0.0.0:0)

Error: getaddrinfo ENOTFOUND [my_cloud_IP] [my_cloud_IP]:[my_cloud_port]

Answer 1

You can create your own "keep alive" agent, and use that one specific agent to send all the HTTP requests:

const http = require('http');
const keepAliveAgent = new http.Agent({ keepAlive: true });
options.agent = keepAliveAgent;
http.request(options, onResponseCallback);

According to the document :

keepAlive Keep sockets around even when there are no outstanding requests, so they can be used for future requests without having to reestablish a TCP connection.