I have setup a Ruby on Rails application on the Home windows 7 Ultimate 64-bit PC.

3 cases of Mongrel are utilized to run the rails program and they're load balanced by Apache 2.2.

Relevant portion of my httpd.conf file is really as adopted:

---------- httpd.conf
#define mongrel cluster
<proxy balancer://mongrelcluster>
BalancerMember http://127.0.0.1:3001
BalancerMember http://127.0.0.1:3002
BalancerMember http://127.0.0.1:3003
</proxy>

Listen 3009

#forward requests to mongrel cluster
<virtualhost *:3009>


  ProxyPass / balancer://mongrelcluster/
  ProxyPassReverse / balancer://mongrelcluster/
  ProxyPreserveHost on
</virtualhost>
----------- httpd.conf

I'm able to access localhost at ports 3001, 3002 and 3003 individually without problems.

After I attempt to access localhost at port 3009 via Apache, I recieve an "Service Temporarily Not available The server is temporarily not able to service your request because of maintenance down time or capacity problems. Please repeat the process later." error message.

Upon checking the Apache error logs:

---- Error log 
[Tue Oct 04 12:46:37 2011] [notice] Child 6168: Child process is running  
[Tue Oct 04 12:46:38 2011] [notice] Child 6168: Acquired the start mutex.
[Tue Oct 04 12:46:38 2011] [notice] Child 6168: Starting 64 worker threads.
[Tue Oct 04 12:46:38 2011] [notice] Child 3052: Released the start mutex
[Tue Oct 04 12:46:39 2011] [notice] Child 3052: All worker threads have exited.
[Tue Oct 04 12:46:39 2011] [notice] Child 3052: Child process is exiting
[Tue Oct 04 12:46:39 2011] [notice] Child 6168: Starting thread to listen on port 80.
[Tue Oct 04 12:46:39 2011] [notice] Child 6168: Starting thread to listen on port 3009.
[Tue Oct 04 12:46:46 2011] [error] (OS 10013)An attempt was made to access a socket in a way forbidden by its access permissions.  : proxy: HTTP: attempt to connect to  127.0.0.1:3001 (127.0.0.1) failed
[Tue Oct 04 12:46:46 2011] [error] ap_proxy_connect_backend disabling worker for (127.0.0.1)
[Tue Oct 04 12:46:46 2011] [error] (OS 10013)An attempt was made to access a socket in a way forbidden by its access permissions.  : proxy: HTTP: attempt to connect to 127.0.0.1:3002 (127.0.0.1) failed
[Tue Oct 04 12:46:46 2011] [error] ap_proxy_connect_backend disabling worker for (127.0.0.1)
[Tue Oct 04 12:46:46 2011] [error] (OS 10013)An attempt was made to access a socket in a way forbidden by its access permissions.  : proxy: HTTP: attempt to connect to 127.0.0.1:3003 (127.0.0.1) failed
[Tue Oct 04 12:46:46 2011] [error] ap_proxy_connect_backend disabling worker for (127.0.0.1)
---- Error log 

The Apache error log implies that link with the Mongrel instances unsuccessful in some way.

It seems in my experience a Home windows 7 problem since the same setup works fine on the Home windows XP system.

All suggestions / tips / solutions are welcome.

I recommend you to definitely change to Linux or Mac OS X if this involves ruby on rails and check out both hands with Nginx. It is a lot more reliable, stable and fast. Rails is loaded with lots of gems that are very helpful. The ruby community, to tell the truth, just does not worry about home windows. The truth is these gems aren't up-to-date for home windows as well as in some rare cases not designed for home windows compatibility. You can test and obtain both hands dirty with Ubuntu(that we experience a really consistent basis) as well as create a jump to nginx or WEBrick which will come with ruby installation itself,as you know it. Thus, to enjoy Ruby on Rails, escaping . of home windows will be a more sensible choice. Read This