Node js process stays on linux ps - linux

Question

I'm currently running a node js server accessible by a specific url on my apache server.
The entire code is:
// server.js
var webshot = require('./lib/webshot');
var fs = require('fs');
var http = require('http');
var bodyParser = require('body-parser');
const used = process.memoryUsage();
var express = require('express');
var app = express();
app.use( bodyParser.urlencoded() );
// your express configuration here
var httpServer = http.createServer(app);
// For http
httpServer.listen(8080);
app.post('/', function (req, res) {
console.log(req.body);
var firstLine = req.body.firstLine;
var secondLine = req.body.secondLine;
var previewID = req.body.previewId;
var productPlate = req.body.prodName;
res.header('Access-Control-Allow-Origin', 'https://citylocs.com');
res.header('Access-Control-Allow-Methods', 'GET, POST, PUT');
res.header('Access-Control-Allow-Headers', 'X-Requested-With, Content-Type');
takeWebshot(firstLine, secondLine, previewID, productPlate)
res.end()
});
function takeWebshot(fLine, sLine, pID, prodPlate) {
var options = {
onLoadFinished: {
fn: function() {
document.getElementById("user_input").value=this.fLineSnapshot;
document.getElementById("second_user_input").value=this.sLineSnapshot;
document.getElementById("preview_btn").click();
},
context: {
fLineSnapshot: fLine,
sLineSnapshot: sLine,
}
},
takeShotOnCallback: true,
captureSelector: '#img_preview_fancybox',
licensePlate: 'Guzman Plate'
};
webshot('example.com/preview/productpreview/testy.html?prod=' + prodPlate, '../screenshot/' + pID +'.png', options, function(err) {
if(!err) { process.exit() }
else { console.log(err);
process.exit() }
});
};
It basically takes some data and does a screen shot of a website using phantom js through this method webshot(). to save memory since this functions multiple times I have process.exit() after webshot() completes in the call back. My expectation is that server.js exists. It's then retired up by pm2. The problem is I'm getting a memory error after some time. After checking running ps aux --sort -rss
I get this:
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 12019 0.0 2.5 224036 105992 ? Ss 04:13 0:06 /usr/local/cpanel/3rdparty/perl/528/bin/perl -T -w /usr/local/cpanel/3rdparty/bin/spamd --max-spare=
root 12237 0.0 2.4 225184 103664 ? S 04:26 0:03 spamd child
root 12238 0.0 2.4 224036 102128 ? S 04:26 0:00 spamd child
root 12239 0.0 2.4 224036 102124 ? S 04:26 0:00 spamd child
mysql 1592 0.2 1.3 1586436 57104 ? Sl Aug29 1:56 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user
named 1056 0.0 0.9 1924092 41828 ? Ssl Aug29 0:00 /usr/sbin/named -u named
root 1380 0.0 0.8 902416 37480 ? Ssl Aug29 0:19 PM2 v3.5.1: God Daemon (/root/.pm2)
root 5032 0.0 0.8 2037540 35732 ? Sl Aug29 0:01 phantomjs /home/ogdi/public_html/preview/productpreview/node-webshot/lib/webshot.phantom.js {
root 9778 0.0 0.8 2037500 35708 ? Sl 02:57 0:01 phantomjs /home/ogdi/public_html/preview/productpreview/node-webshot/lib/webshot.phantom.js {
root 18725 0.0 0.8 2037500 35680 ? Sl 08:09 0:00 phantomjs /home/ogdi/public_html/preview/productpreview/node-webshot/lib/webshot.phantom.js {
root 7577 0.0 0.8 2037460 35676 ? Sl 01:46 0:01 phantomjs /home/ogdi/public_html/preview/productpreview/node-webshot/lib/webshot.phantom.js {
It's telling me the phantom js script is still active since yesterday. It appears several more times. Why is that if I process.exit() successfully?
EDIT:
I manually killed a bunch of those phantom js commands. I diagnosed one a little more. and it says STAT Sl which means it's Sleep, multi thread. according to what I read.
Webshot link: https://raw.githubusercontent.com/brenden/node-webshot/master/lib/webshot.js
Webshot phantom link: https://raw.githubusercontent.com/brenden/node-webshot/master/lib/webshot.phantom.js

Answer 1

process.exit() is not called if there is an error. In the event of an error, is there any point in the process continuing?
webshot('example.com/preview/productpreview/testy.html?prod=' + prodPlate, '../screenshot/' + pID +'.png', options, function(err) {
if (err) { console.log(err) }
process.exit(err)
});