几天来，我一直在寻找一个有效的错误解决方案
错误:EMFILE，打开的文件太多
似乎很多人都有同样的问题。通常的答案是增加文件描述符的数量。所以，我试过了:
sysctl -w kern.maxfiles=20480
缺省值为10240。在我看来，这有点奇怪，因为我在目录中处理的文件数量低于10240。更奇怪的是，在增加了文件描述符的数量之后，我仍然收到相同的错误。
第二个问题:
经过多次搜索，我找到了一个解决“打开文件太多”问题的方法:
var requestBatches = {};
function batchingReadFile(filename, callback) {
// First check to see if there is already a batch
if (requestBatches.hasOwnProperty(filename)) {
requestBatches[filename].push(callback);
return;
}
// Otherwise start a new one and make a real request
var batch = requestBatches[filename] = [callback];
FS.readFile(filename, onRealRead);
// Flush out the batch on complete
function onRealRead() {
delete requestBatches[filename];
for (var i = 0, l = batch.length; i < l; i++) {
batch[i].apply(null, arguments);
}
}
}
function printFile(file){
console.log(file);
}
dir = "/Users/xaver/Downloads/xaver/xxx/xxx/"
var files = fs.readdirSync(dir);
for (i in files){
filename = dir + files[i];
console.log(filename);
batchingReadFile(filename, printFile);
不幸的是，我仍然收到相同的错误。
这段代码有什么问题?
你读的文件太多了。节点异步读取文件，它会一次读取所有文件。所以你可能读到了10240的限制。
看看这是否有效:
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()
对于同一个问题，我做了上面提到的所有事情，但都不起作用。我试了下，它工作100%。简单的配置更改。
选项1:设置限制(大多数情况下都不起作用)
user@ubuntu:~$ ulimit -n 65535
检查电流限制
user@ubuntu:~$ ulimit -n
1024
选项2:将可用限制增加到例如65535
user@ubuntu:~$ sudo nano /etc/sysctl.conf
添加下面的行
fs.file-max = 65535
运行此命令以刷新新的配置
user@ubuntu:~$ sudo sysctl -p
编辑以下文件
user@ubuntu:~$ sudo vim /etc/security/limits.conf
向它添加以下行
root soft nproc 65535
root hard nproc 65535
root soft nofile 65535
root hard nofile 65535
编辑以下文件
user@ubuntu:~$ sudo vim /etc/pam.d/common-session
把这一行加进去
session required pam_limits.so
注销并登录并尝试以下命令
user@ubuntu:~$ ulimit -n
65535
选项3:只添加这一行
DefaultLimitNOFILE=65535
到 /etc/systemd/system.conf 和 /etc/systemd/user.conf
你读的文件太多了。节点异步读取文件，它会一次读取所有文件。所以你可能读到了10240的限制。
看看这是否有效:
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()
