深入浅出Nodejs--雪崩问题
请问哪位大神测试过雪崩的问题:node-mysql例子？我怎么不会测试？我觉得我的代码写错了，请指点~
var EventProxy = require('eventproxy');
var proxy = new EventProxy();
var mysql = require('mysql');
var http = require('http');
var option = {
host:'localhost',
port:3306,
database:'test',
user:'test',
password:'test',
}
var connection = mysql.createConnection(option);
var status = "ready";
http.createServer(function (request, response) {
proxy.once("selected", function(result){
response.writeHead(200);
response.end('11');
});
if (status === "ready") {
status = "pending";
connection.query("select * from test", function (err,results) {
console.log('1');
proxy.emit("selected", results);
status = "ready";
});
}
}).listen(7777);
管理员提示：学一下markdown语法
4 回复
我想大概是这么个意思
var mysql = require('mysql');
var http = require('http');
var option = {
host: '123.57.143.189',//这是我的服务器，随意使用
port: 3306,
database: 'test',
user: 'readonly',
password: 'readonly'
}
var connection = mysql.createConnection(option);
var events = require('events');
var proxy = new events.EventEmitter();
var status = "nodata";//默认状态没有数据
http.createServer(function (request, response) {
select(send.bind(response));
}).listen(8080);
//声明回调函数
function send(data) {
this.end(data.toString());//向客户端发送数据
}
var select = function(callback){
proxy.once('selected',callback);//把回调压队队列中
if (status === 'nodata') {//如果没有数据，那么去数据库中获取数据,
status = 'querying';//修改状态为查询中，其它请求再也进不来这个分支了
connection.query('select 100 num', function (err,results) {
proxy.emit('query_over', results[0]['num']);//查询结束后发射事件,并把数据做为参数递给回调函数
status = 'nodata';//把状态改回为nodata,以供下次查询
});
}
}
我写的简单模拟测试例子，已测试通过
var EventEmitter = require('events').EventEmitter;
var proxy = new EventEmitter();
proxy.setMaxListeners(0);
var selectSqls = [];
var flags = [];
for(var i=0;i<10;i++){
flags.push('ready');
for(var j=0;j<10;j++){
selectSqls.push(j);
}
}
var count=1;
var http=require('http');
var select = function (num,callback) {
proxy.once(''+num,callback);
if(flags[num] === 'ready'){
flags[num] = 'pending';
http.get("http://www.cnblogs.com/", function(res) {
console.log("Got response: " + count++);
proxy.emit(''+num,num);
flags[num] = 'ready';
//res.resume();
}).on('error', function(e) {
console.log("Got error: " + e.message);
});
}
};
var callNum= function(num){
console.log(num + ':ok');
};
for(var num=0;num<selectSqls.length;num++){
var sqlNum = selectSqls[num];
//console.log(sqlNum);
select(sqlNum,callNum);
}
