我希望外面的某个地方能够在这方面帮助我。我的生产环境如下：
Rails 2.3.5
Passenger 2.2.11
Nginx
Monit
似乎一切都按预期进行，但是，每天 2 到 3 次，我收到来自 Monit 的电子邮件，如下所示：
monit alert -- Connection failed nginx
To: myemail@domain.com
Connection failed Service nginx
Date: Thu, 11 Nov 2010 10:46:44 +0000
Action: restart
Host: mydomain
Description: 'nginx' failed, cannot open a connection to INET[mydomain.com:80] via TCP
Your faithful employee,
monit
然后大约 30 秒后，我收到另一封电子邮件，如下所示：
Connection passed Service nginx
Date: Thu, 11 Nov 2010 10:47:16 +0000
Action: alert
Host: mydomain
Description: 'nginx' connection passed to INET[mydomain.com:80] via TCP
Your faithful employee,
monit
在我的监控配置文件中，我有以下内容：
set daemon 30
check process nginx with pidfile /opt/nginx/logs/nginx.pid
start program = "/opt/nginx/sbin/nginx"
stop program = "/opt/nginx/sbin/nginx -s stop"
if failed host mydomain.com port 80 protocol http request / then restart
if 5 restarts within 5 cycles then timeout
在那个时候的 Nginx 日志中，我有这个：
2010/11/11 10:46:44 [notice] 3812#0: signal process started
*** Exception Errno::EPIPE in Passenger RequestHandler (Broken pipe) (process 3803):
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/rack/request_handler.rb:94:in `write'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/rack/request_handler.rb:94:in `process_request'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_request_handler.rb:207:in `main_loop'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/railz/application_spawner.rb:418:in `start_request_handler'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/railz/application_spawner.rb:358:in `handle_spawn_application'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/utils.rb:184:in `safe_fork'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/railz/application_spawner.rb:354:in `handle_spawn_application'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_server.rb:352:in `__send__'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_server.rb:352:in `main_loop'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_server.rb:196:in `start_synchronously'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_server.rb:163:in `start'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/railz/application_spawner.rb:213:in `start'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/spawn_manager.rb:262:in `spawn_rails_application'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_server_collection.rb:126:in `lookup_or_add'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/spawn_manager.rb:256:in `spawn_rails_application'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_server_collection.rb:80:in `synchronize'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_server_collection.rb:79:in `synchronize'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/spawn_manager.rb:255:in `spawn_rails_application'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/spawn_manager.rb:154:in `spawn_application'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/spawn_manager.rb:287:in `handle_spawn_application'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_server.rb:352:in `__send__'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_server.rb:352:in `main_loop'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/lib/phusion_passenger/abstract_server.rb:196:in `start_synchronously'
from /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/gems/1.8/gems/passenger-2.2.11/bin/passenger-spawn-server:61
我无法弄清楚是什么导致了这个问题。我尝试在乘客配置文件中将 max_pool_size 设置为 30，但它还没有任何区别。
任何帮助，将不胜感激。
谢谢。