Node.js app is working slow after 24 hours, what might be the reasons?

Question

I' am working on multiplayer game and server side is written with node.js with box2dweb. Server is on aws it's ubuntu 15 LTS (1GB RAM) virtual machine. Game is running fine when i start it within firs couple of hours, but after ~24h game is slowing down even thou no one have been playing during last 22h and last object was spawned 23 h ago. I've tried to use node.js profiler but i have very similar results when i start app and after one day of aplication working. What should i do? What is possible cause of my issue?

I've monitored time usage of functions among 10 min and here are the results :

gamelogic.update() ~40%

b2dWorld.update() ~47%

My profiller code:

var profiler = require('v8-profiler');
var fs = require('fs');
var startProfiling = function(duration){
    profiler.startProfiling('1', true);
    setTimeout(function(){
        var profile1 = profiler.stopProfiling('1');

        profile1.export(function(error, result) {
            fs.writeFile('./profile.cpuprofile', result);
            profile1.delete();
            console.log("Profile saved.");
        });
    },duration);
}
setTimeout(function(){
    startProfiling(1000 * 60 * 10);
},1000 * 60 * 60 * 24);

Should I stop listen to socket events on socekt before i delete socket ?

Top results in bash shell: - after 10 min of runnign 10% CPU usage and 8% RAM usage - after 4 days of running 80% CPU usage and 30% RAM usage

While measuring i have the same amount of game objects in the game + one player conected to server.

I have this message from node.js "(node:1324) Warning: Possible EventEmitter memory leak detected. 11 upgradeRequest listeners added. Use emitter.setMaxListeners() to increase limit" does garbage from this stay after deleting socket which called for too many same listener ?