Can Memory leaks cause getaddrinfo EMFILE - linux

Question

I'm having some trouble with my NodeJS API.
Sometimes, it returns, ConnectionError: getaddrinfo EMFILE and is all is fuc** after this.
So, I've started to investigate. I found it would be caused by the "to many files descriptors open". We can apparently increase the number of open files that are authorized but it would not definitely fix the problem.
I found in this article, that we can increase the file descriptors settings and the ulimit. But what is the difference?
Then, to try to isolate my problem, I've run the lsof -i -n -P | grep nodejs command. Indeed, the number of connections established is increasing, so I imagine I have somewhere in my code some connections that are not closed.
I have some fs.readFileSync and fs.readDirSync etc… but I have not set the autoClose:true. Did you think it would be that?
Do you have any ideas or advice?
PS : the App run on a Ubuntu machine
EDIT , 16-02-2016
I have ran this command on my production machine lsof -i -n -P | grep nodejs
What I see is something like this:
...
nodejs 27596 root 631u IPv4 109781565 0t0 TCP 127.0.0.1:45268->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 632u IPv4 109782317 0t0 TCP 172.31.58.93:4242->172.31.55.229:61616 (ESTABLISHED)
nodejs 27596 root 633u IPv4 109779882 0t0 TCP 127.0.0.1:45174->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 634u IPv4 109779884 0t0 TCP 127.0.0.1:45175->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 635u IPv4 109781569 0t0 TCP 127.0.0.1:45269->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 636u IPv4 109781571 0t0 TCP 127.0.0.1:45270->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 637u IPv4 109782319 0t0 TCP 127.0.0.1:45293->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 642u IPv4 109781790 0t0 TCP 127.0.0.1:45283->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 643u IPv4 109781794 0t0 TCP 127.0.0.1:45284->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 644u IPv4 109781796 0t0 TCP 127.0.0.1:45285->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 645u IPv4 109781798 0t0 TCP 172.31.58.93:4242->172.31.55.229:61602 (ESTABLISHED)
nodejs 27596 root 646u IPv4 109781800 0t0 TCP 127.0.0.1:45286->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 647u IPv4 109781802 0t0 TCP 172.31.58.93:4242->172.31.0.198:1527 (ESTABLISHED)
nodejs 27596 root 648u IPv4 109781804 0t0 TCP 127.0.0.1:45287->127.0.0.1:7272 (ESTABLISHED)
nodejs 27596 root 649u IPv4 109781806 0t0 TCP 127.0.0.1:45288->127.0.0.1:7272 (ESTABLISHED)
But I don't know what it means, do you have any ideas about this?
Thanks a lot.

Answer 1

So I thought I found out what is going on!
I use Redis & Redis session npm modules for my cart storage, but when I created, updated, I created a connection to Redis, each time, before using it.
var session = new Sessions({ port : conf.redisPort, host : conf.redisHost});
session.get({
app : rsapp,
token : this.sessionToken },
function(err, resp) {
// here some workin'
})
Now I just created the connection when my app starts and store this as a singleton and use whenever I want.
// At the start of the App
var NS = {
sessions : new RedisSessions({port: config.redisPort, host: config.redisHost}),
};
// Later somewhere in the app
NS.session.get({
app : rsapp,
token : this.sessionToken },
function(err, resp) {
// here some workin'
})
It was pretty obvious but now I found it… If it can help someone, I'll mark this one as solved.