How make a node.js script to be restarted every hour?

Question

How make a node.js script to be restarted every hour?

3.6k views Asked by Marin Draganov At 08 October 2018 at 17:51

I have a node.js script that creates a websocket connection to a crypto trading site (bitmex). It streams price data.

For some reason after an hour or two the stream goes bad and the prices (if streamed at all) are inacurate.

For now I restart it manually every hour but I need that to be done automatically. How can I do that?

Here is the code of the script:

var WebSocket = require('ws');
var ws = new WebSocket("wss://www.bitmex.com/realtime");

var couchbase = require('couchbase')
var cluster = new couchbase.Cluster('couchbase://localhost/');
cluster.authenticate('xxxxxx', 'xxxxxxx');
var bucket = cluster.openBucket('test');
var N1qlQuery = couchbase.N1qlQuery;

let num_msg = 0;        
ws.onopen = function(){
    ws.send(JSON.stringify({"op": "subscribe", "args": [    
    "trade:XBTUSD",
    "trade:LTCZ18"]
    }))
};
ws.onmessage = function(msg){
    var response = JSON.parse(msg.data);
    num_msg++
    if(num_msg > 50) {
        var coin = response['data'][0]['symbol'];
        var price = response['data'][0]['price'];
        //console.log(coin + ":" + price + "\n");
        bucket.manager().createPrimaryIndex(
            function(){
                bucket.upsert(  coin, 
                                {
                                'price': price
                                },
                                function (err, result){
            });
        });

    }

};

EDIT: I missed to mention that currently I use Windows 7 system (eventhough I do need to move to Ubuntu or similar).

EDIT 2: Final version of my code :)

const cron = require("node-cron");
var WebSocket = require('ws');
var couchbase = require('couchbase');
var dateTime = require('node-datetime');

let now = new Date();
minutes = now.getMinutes() + 1;
if(minutes + 30 > 59) {
    minutes1 = minutes - 30;
} else {
    minutes1 = minutes - 30;
}
if(minutes > minutes1) {
    s_cron = minutes1 + "," + minutes +  " * * * *";
} else {
    s_cron = minutes + "," + minutes1 +  " * * * *";
}
cron.schedule(s_cron, () => {
    console.log("---------------------");
    console.log("Running Cron Job");
    var dt = dateTime.create();
    var formatted = dt.format('Y-m-d H:M:S');
    console.log(formatted);    
    // create bitmex ws
        var ws = new WebSocket("wss://www.bitmex.com/realtime");
        // connect to couchbase
        var cluster = new couchbase.Cluster('couchbase://localhost/');
        cluster.authenticate('xxxxxxxx', 'xxxxxxxxxx');
        var bucket = cluster.openBucket('test');
        var N1qlQuery = couchbase.N1qlQuery;

        let num_msg = 0;        
        ws.onopen = function(){
            ws.send(JSON.stringify({"op": "subscribe", "args": [    
                "trade:XBTUSD",
                "trade:LTCZ18"]
            }))
        };
        ws.onmessage = function(msg){
            var response = JSON.parse(msg.data);
            num_msg++
            if(num_msg > 50) {
                var coin = response['data'][0]['symbol'];
                var price = response['data'][0]['price'];
                //console.log(coin + ":" + price + "\n");
                bucket.manager().createPrimaryIndex(
                    function(){
                        bucket.upsert(  coin, 
                                        {
                                        'price': price
                                        },
                                        function (err, result){
                                            //bucket.disconnect()
                    });
                });

            }

        };
  });

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