node and Error: EMFILE, too many open files

Question

For some days I have searched for a working solution to an error

Error: EMFILE, too many open files

It seems that many people have the same proble

Answer 1

You're reading too many files. Node reads files asynchronously, it'll be reading all files at once. So you're probably reading the 10240 limit.

See if this works:

var fs = require('fs')
var events = require('events')
var util = require('util')
var path = require('path')

var FsPool = module.exports = function(dir) {
    events.EventEmitter.call(this)
    this.dir = dir;
    this.files = [];
    this.active = [];
    this.threads = 1;
    this.on('run', this.runQuta.bind(this))
};
// So will act like an event emitter
util.inherits(FsPool, events.EventEmitter);

FsPool.prototype.runQuta = function() {
    if(this.files.length === 0 && this.active.length === 0) {
        return this.emit('done');
    }
    if(this.active.length < this.threads) {
        var name = this.files.shift()

        this.active.push(name)
        var fileName = path.join(this.dir, name);
        var self = this;
        fs.stat(fileName, function(err, stats) {
            if(err)
                throw err;
            if(stats.isFile()) {
                fs.readFile(fileName, function(err, data) {
                    if(err)
                        throw err;
                    self.active.splice(self.active.indexOf(name), 1)
                    self.emit('file', name, data);
                    self.emit('run');

                });
            } else {
                self.active.splice(self.active.indexOf(name), 1)
                self.emit('dir', name);
                self.emit('run');
            }
        });
    }
    return this
};
FsPool.prototype.init = function() {
    var dir = this.dir;
    var self = this;
    fs.readdir(dir, function(err, files) {
        if(err)
            throw err;
        self.files = files
        self.emit('run');
    })
    return this
};
var fsPool = new FsPool(__dirname)

fsPool.on('file', function(fileName, fileData) {
    console.log('file name: ' + fileName)
    console.log('file data: ', fileData.toString('utf8'))

})
fsPool.on('dir', function(dirName) {
    console.log('dir name: ' + dirName)

})
fsPool.on('done', function() {
    console.log('done')
});
fsPool.init()