我将以下内容用于我的 rails 应用程序。
ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux]
Rails 3.0.5
Phusion Passenger version 3.0.5
该应用程序位于一个 4GB RAM 的 linux 盒子中。我最近将我的 rails 应用程序从 3.0.1 升级到了 3.0.5，以获得他们上周发布的关键安全修复程序。
我一直注意到一件奇怪的事情。我有以下乘客设置/etc/apache2/apache2.conf
PassengerMaxPoolSize 10
PassengerMaxInstancesPerApp 5
但是乘客产生了 18 个机架实例。它只是服务器中的一个应用程序，没有别的。应用程序的响应时间变慢。我怀疑额外的机架实例（突然出现）占用了额外的内存。
这是我的free -m输出
total used free shared buffers cached
Mem: 4011 3992 19 0 1 22
-/+ buffers/cache: 3968 43
Swap: 8191 5780 2411
这是我的passenger-status命令输出和passenger-memory-stats输出。
passenger-status：
----------- General information -----------
max = 10
count = 5
active = 1
inactive = 4
Waiting on global queue: 0
----------- Application groups -----------
/home/anand/public_html/railsapp/current:
App root: /home/anand/public_html/railsapp/current
* PID: 6704 Sessions: 0 Processed: 72 Uptime: 9m 58s
* PID: 6696 Sessions: 0 Processed: 99 Uptime: 9m 58s
* PID: 6712 Sessions: 0 Processed: 69 Uptime: 9m 57s
* PID: 6688 Sessions: 0 Processed: 52 Uptime: 9m 58s
* PID: 6677 Sessions: 1 Processed: 83 Uptime: 11m 28s
passenger-memory-stats：
--------- Apache processes ---------
PID PPID VMSize Private Name
------------------------------------
6470 1 95.5 MB 0.3 MB /usr/sbin/apache2 -k start
6471 6470 94.7 MB 0.5 MB /usr/sbin/apache2 -k start
6488 6470 378.4 MB 4.6 MB /usr/sbin/apache2 -k start
6489 6470 378.0 MB 3.8 MB /usr/sbin/apache2 -k start
6774 6470 377.4 MB 3.0 MB /usr/sbin/apache2 -k start
### Processes: 5
### Total private dirty RSS: 12.20 MB
-------- Nginx processes --------
### Processes: 0
### Total private dirty RSS: 0.00 MB
------ Passenger processes ------
PID VMSize Private Name
---------------------------------
6472 87.1 MB 0.2 MB PassengerWatchdog
6475 100.9 MB 3.2 MB PassengerHelperAgent
6477 39.4 MB 4.8 MB Passenger spawn server
6482 70.7 MB 0.6 MB PassengerLoggingAgent
6677 289.1 MB 114.3 MB Rack: /home/anand/public_html/railsapp/current
6684 287.3 MB 17.2 MB Rack: /home/anand/public_html/railsapp/current
6688 295.6 MB 82.4 MB Rack: /home/anand/public_html/railsapp/current
6696 299.2 MB 88.9 MB Rack: /home/anand/public_html/railsapp/current
6704 299.0 MB 87.3 MB Rack: /home/anand/public_html/railsapp/current
6712 312.6 MB 113.3 MB Rack: /home/anand/public_html/railsapp/current
23808 1174.7 MB 190.9 MB Rack: /home/anand/public_html/railsapp/current
26271 1767.0 MB 690.0 MB Rack: /home/anand/public_html/railsapp/current
28888 1584.7 MB 177.8 MB Rack: /home/anand/public_html/railsapp/current
32403 1638.5 MB 230.3 MB Rack: /home/anand/public_html/railsapp/current
32427 1573.6 MB 253.4 MB Rack: /home/anand/public_html/railsapp/current
32443 1576.0 MB 234.7 MB Rack: /home/anand/public_html/railsapp/current
### Processes: 16
### Total private dirty RSS: 2289.34 MB
这里出了什么问题？Rails 3.0.5 是否启动了额外的机架应用程序。请帮忙。