我是 nodejs 和 mongdb 的新手，我将在我的一个项目中使用它们，一旦我的 db 连接正常工作，我很震惊地看到我的代码确实有多少数据库连接。所以，给定这个简单的代码段：
var express = require('express');
var mongo = require('mongodb');
var app = express();
// Further details:
// nodejs: v0.8.18
// mongod: v2.2.2
// node's mongodb driver: v1.2.10
app.get('/', function(req, res){
res.send('<h1>Ok</h1>');
});
var setUp = function() {
// get a handler to the testDB Database
mongo.Db.connect('mongodb://localhost:27017/testDB', function(err, db) {
if (err)
throw err;
// create a test collection in the database
db.createCollection('test', function(err, test) {
if (err)
throw err;
// insert a dummy document into the test collection
test.insert({'name':'admin', 'pass':'admin'});
app.listen(3000);
console.log('App listening on port 3000');
});
});
}
setUp();
当 nodejs 进程启动时，mongo 守护进程会输出这段日志：
... connection accepted from 127.0.0.1:40963 #34 (1 connection now open)
... connection accepted from 127.0.0.1:40964 #35 (2 connections now open)
... connection accepted from 127.0.0.1:40965 #36 (3 connections now open)
... connection accepted from 127.0.0.1:40966 #37 (4 connections now open)
... connection accepted from 127.0.0.1:40967 #38 (5 connections now open)
... connection accepted from 127.0.0.1:40968 #39 (6 connections now open)
... end connection 127.0.0.1:40963 (5 connections now open)
... allocating new datafile /var/data/testDB.ns, filling with zeroes...
...
而这个过程终止时：
... connection 127.0.0.1:40964 (4 connections now open)
... connection 127.0.0.1:40965 (3 connections now open)
... connection 127.0.0.1:40966 (2 connections now open)
... connection 127.0.0.1:40967 (1 connection now open)
... connection 127.0.0.1:40968 (0 connections now open)
mongo 驱动程序是否真的需要与 mongod 建立如此多的连接才能获得单个数据库处理程序，或者我实现这个的方式有什么问题？我真的希望在那里只看到一个打开的连接......