I'm getting error ECONNRESET when uploading a lot of users

[Milanw2]

I have to upload every user one by one because of the thing that if I upload a JSON with existing users in it, it doesn't upload any user. But now I'm getting these errors for every failed uploaded user:

[Unhandled rejection RequestError: Error: read ECONNRESET
    at new RequestError (C:\Users\Milan\Documents\Octopus\Octopus 2.0\node_modules\request-promise\lib\errors.js:11:15)
    at Request.RP$callback [as _callback] (C:\Users\Milan\Documents\Octopus\Octopus 2.0\node_modules\request-promise\lib\rp.js:60:32)
    at self.callback (C:\Users\Milan\Documents\Octopus\Octopus 2.0\node_modules\request\request.js:186:22)
    at emitOne (events.js:96:13)
    at Request.emit (events.js:191:7)
    at Request.onRequestError (C:\Users\Milan\Documents\Octopus\Octopus 2.0\node_modules\request\request.js:845:8)
    at emitOne (events.js:96:13)
    at ClientRequest.emit (events.js:191:7)
    at Socket.socketErrorListener (_http_client.js:358:9)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:191:7)
    at emitErrorNT (net.js:1279:8)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)](url)

[mudrd8mz]

It is not clear to me how is this directly related to the moodle client. May it be rather caused by the way how you use it in your app?

[Milanw2]

Then please tell me what I'm doing wrong. This is my code:

function send_user_to_moodle(client, username, password, firstname, lastname, email) {
    client.call({
        wsfunction: "core_user_create_users",
        method: "POST",
        args: {
            users: [
                {
                    username: username,
                    password: password,
                    firstname: firstname,
                    lastname: lastname,
                    email: email
                }
            ]
        }
    }).then(function (info) {
        }
    });
};

This code is run over and over again for 50.000 users. This because of the reason explained in the original question.

Thanks for your quick reply!