多节点mongodb本地连接
当我运行这个Node.js代码：
var mongodb = require('mongodb'), MongoClient = mongodb.MongoClient; MongoClient.connect('mongodb://localhost:27017/mydb', function(error, db) { if (error) { throw (error); } console.log('Connected!'); }); mongo日志显示打开5个连接：
sudo mongod mongod --help for help and startup options 2014-11-04T21:03:23.107-0700 [initandlisten] MongoDB starting : pid=27572 port=27017 dbpath=/data/db 64-bit host=mylaptop 2014-11-04T21:03:23.107-0700 [initandlisten] db version v2.6.2 2014-11-04T21:03:23.107-0700 [initandlisten] git version: nogitversion 2014-11-04T21:03:23.107-0700 [initandlisten] build info: Darwin minimountain.local 12.5.0 Darwin Kernel Version 12.5.0: Sun Sep 29 13:33:47 PDT 2013; root:xnu-2050.48.12~1/RELEASE_X86_64 x86_64 BOOST_LIB_VERSION=1_49 2014-11-04T21:03:23.107-0700 [initandlisten] allocator: tcmalloc 2014-11-04T21:03:23.107-0700 [initandlisten] options: {} 2014-11-04T21:03:23.110-0700 [initandlisten] journal dir=/data/db/journal 2014-11-04T21:03:23.110-0700 [initandlisten] recover : no journal files present, no recovery needed 2014-11-04T21:03:23.136-0700 [initandlisten] waiting for connections on port 27017 2014-11-04T21:03:28.315-0700 [initandlisten] connection accepted from 127.0.0.1:61163 #1 (1 connection now open) 2014-11-04T21:03:28.323-0700 [conn1] end connection 127.0.0.1:61163 (0 connections now open) 2014-11-04T21:03:28.326-0700 [initandlisten] connection accepted from 127.0.0.1:61164 #2 (1 connection now open) 2014-11-04T21:03:28.326-0700 [initandlisten] connection accepted from 127.0.0.1:61165 #3 (2 connections now open) 2014-11-04T21:03:28.327-0700 [initandlisten] connection accepted from 127.0.0.1:61166 #4 (3 connections now open) 2014-11-04T21:03:28.328-0700 [initandlisten] connection accepted from 127.0.0.1:61167 #5 (4 connections now open) 2014-11-04T21:03:28.328-0700 [initandlisten] connection accepted from 127.0.0.1:61168 #6 (5 connections now open)
这看起来正确吗？
当然。 MongoClient使用节点本地驱动程序中的连接池选项。 这实际上是一个服务器对象 ，默认情况下连接数是5。
你可以像这样覆盖设置：
var async = require('async'), mongo = require('mongo'), MongoClient = mongo.MongoClient; MongoClient.connect('mongodb://localhost/test',{ server: { poolSize: 1 }},function(err,db) { });
因此，在服务器选项中设置“poolSize”指定池中使用的连接数。 尽pipe如此，最好坚持默认或更高。