Node.js在循环中发送http请求 [英] Node.js sending http request in a loop
问题描述
我实际上遇到了使用node.js
执行的javascript代码的问题。我需要将循环中的http请求发送到远程服务器(我在代码中设置了www.google.ca)。
这是我的代码:
I'm actually facing a problem with my javascript code executed with node.js i need to send http requests in a loop to a distant server (i set www.google.ca in the code). Here is my code :
var http = require('http');
var options = {
hostname: 'www.google.ca',
port: 80,
path: '/',
method: 'GET'
};
function sendRequest(options){
console.log('hello');
var start = new Date();
var req = http.request(options,function(res) {
console.log('Request took:', new Date() - start, 'ms');
});
req.on('error', function(e) {
console.log('problem with request: ' + e.message);
});
req.end();
};
for(var i=0;i<10;i++){
sendRequest(options);
}
我遇到的问题是,无论我经过多少次循环,我得到的回应只有他们中的第一个。对于其余的请求,函数sendRequest()被调用,但我没有得到任何响应,也没有错误消息。然后程序终止。
但是当我将localhost设置为主机时,它工作正常。
有人能解决这个问题吗?
提前致谢!
The problem I have is that, no matter how many times i go through my loop, i get a response for only the 5 first of them. For the rest of the requests, the function sendRequest() is called but I don't get any responses, neither error message. And then the program terminates. However it works fine when I set localhost as a host. Is anyone would have a solution to this problem ? Thanks in advance !
推荐答案
您的机器或远程机器可能会被同时发出的10个请求所淹没。尝试一次发送一个,您必须等到第一个请求完成后再继续。一个简单的方法是 async.timesSeries
perhaps either your machine or the remote machine is getting overwhelmed by the 10 simultaneous requests you make. try sending them one at a time, you will have to wait until the first request completes before continuing. one easy way to do so is with async.timesSeries
var http = require('http');
var async = require('async');
var options = {
hostname: 'www.google.ca',
port: 80,
path: '/',
method: 'GET'
};
function sendRequestWrapper(n, done){
console.log('Calling sendRequest', n);
sendRequest(options, function(err){
done(err);
});
};
function sendRequest(options, callback){
//console.log('hello');
var start = new Date();
var req = http.request(options,function(res) {
// I don't know if this callback is called for error responses
// I have only used the `request` library which slightly simplifies this
// Under some circumstances you can accidentally cause problems by calling
// your callback function more than once (e.g. both here and on('error')
console.log('Request took:', new Date() - start, 'ms');
callback(null);
});
req.on('error', function(e) {
console.log('problem with request: ' + e.message);
callback(err);
});
req.end();
};
async.timesSeries(10, sendRequestWrapper);
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