Mongo DB初始连接池保持打开状态？

目前使用Node.js（Native MongoDB）驱动程序来处理Mongodb，我知道可以设置池连接计数，但不pipe是否观察到相同的行为。

有问题的代码：

(function init(){ db.connect("mongodb://localhost/test",function(err, database){ }); })(); 

这是来自服务器的日志：

 Thu Dec 06 20:19:32 [initandlisten] connection accepted from 127.0.0.1:58663 #6 (1 connection now open) Thu Dec 06 20:19:32 [initandlisten] connection accepted from 127.0.0.1:58664 #7 (2 connections now open) Thu Dec 06 20:19:32 [initandlisten] connection accepted from 127.0.0.1:58665 #8 (3 connections now open) Thu Dec 06 20:19:32 [initandlisten] connection accepted from 127.0.0.1:58666 #9 (4 connections now open) Thu Dec 06 20:19:32 [initandlisten] connection accepted from 127.0.0.1:58667 #10 (5 connections now open) Thu Dec 06 20:19:36 [conn9] end connection 127.0.0.1:58666 (4 connections now op en) Thu Dec 06 20:19:36 [conn10] end connection 127.0.0.1:58667 (4 connections now o pen) Thu Dec 06 20:19:36 [conn8] end connection 127.0.0.1:58665 (4 connections now op en) Thu Dec 06 20:19:36 [conn6] end connection 127.0.0.1:58663 (4 connections now op en) Thu Dec 06 20:19:36 [conn7] end connection 127.0.0.1:58664 (4 connections now op en) 

连接显然正在closures，即使连接正确递增，当前打开的连接计数也不会减less。 意图行为？

PS。 请不要使用用于mongodb的nodejs包装来回答。

Answer 1

这是MongoDB计数器的问题。 数据库在closures所有连接（多个closures信号）时asynchronous工作，发生得非常快，以至于无法跟上更新计数器。 在浏览MongoDB源代码之后，您可以看到消息输出在柜台更新附近。

下面类似的输出，但高达1ms的精度，这说明问题IMO好一点。

 Mon Dec 2 17:42:09.059 [conn675] end connection 127.0.0.1:65198 (9 connections now open) Mon Dec 2 17:42:09.059 [conn676] end connection 127.0.0.1:65199 (8 connections now open) Mon Dec 2 17:42:09.059 [conn677] end connection 127.0.0.1:65200 (8 connections now open) Mon Dec 2 17:42:09.059 [conn678] end connection 127.0.0.1:65201 (7 connections now open) Mon Dec 2 17:42:09.059 [conn679] end connection 127.0.0.1:65202 (6 connections now open) Mon Dec 2 17:42:09.059 [conn680] end connection 127.0.0.1:65203 (5 connections now open) Mon Dec 2 17:42:09.059 [conn681] end connection 127.0.0.1:65204 (4 connections now open) Mon Dec 2 17:42:09.059 [conn682] end connection 127.0.0.1:65205 (3 connections now open) Mon Dec 2 17:42:09.059 [conn683] end connection 127.0.0.1:65206 (2 connections now open) Mon Dec 2 17:42:09.059 [conn684] end connection 127.0.0.1:65207 (2 connections now open)