About pound

[satimis]

Hi folks,


What will be the use of "pound"?

Apsis Gmbh


I don't have a clear picture of its application on reading its website. Any example? TIA


B.R.
satimis

[Cabhan]

Alrighty. Let's suppose I have a very popular website. It is possible that I may have many webservers that support this site. This way, if I get 1000 requests, I can have 5 servers each dealing with 200 requests, rather than 1 dealing with 1000. However, to do this, I need some way of giving each incoming request to the correct backend server.

So one thing that Pound does is that it does load balancing. This means that if one server is dealing with 100 requests, and a second is dealing with 5, it will send incoming requests to the second one. This allows you optimum use of your distributed backend.

It is also an SSL wrapper. SSL allows for encrypted and verified communication between two people. However, some web servers do not support SSL. So Pound will accept SSL connections, decrypt them, and pass unencrypted connections to your backend servers. Presumably, it will then re-encrypt the command for return to the client.

Finally, it is also a sanitizer. So whenever you click on a link, your web browser sends an HTTP or HTTPS request (the latter is for SSL connections). These requests basically say "Hi! I'm Mozilla Firefox. I would like to request the page located at this URL. Here's some other assorted information about me." and so on. These requests adhere to a standard (obviously). Therefore, Pound will make sure that the request is valid before passing it on to the backend. This can avoid problems if the backend does not check for these itself.

Does that make more sense?

[satimis]

Hi Cabhan,


Thanks for your detail advice.

It is also an SSL wrapper. SSL allows for encrypted and verified communication between two people. However, some web servers do not support SSL. So Pound will accept SSL connections, decrypt them, and pass unencrypted connections to your backend servers. Presumably, it will then re-encrypt the command for return to the client. .........

This may be my interest. The backside story leading to the discovery of "pound" on googling is as follows;

I'm doing a test on virturalization with following setup;
(This is a test NOT for production)


VMWare Server

Ubuntu 7.04 server amd64 (Host)
(Mail Server with SquirrelMail running)
Internal IP addr 192.168.0.10
Port forwarded 80, 443 (orginal setup on router)


CentOS 5 x56_64 (Guest)
(Web Server)
Internal IP addr 192.168.0.20
Port forwarded 8080 (orginal setup on router]


The Mail Server is running w/o problem. The Web Server can be visited with;

https://public_ip:8080


I expect to exclude ":8080", therefore re-setup the router as follows;

Ports forward to Ubuntu - 80 and 8080
Port forward to CentOS - 443


On CentOS;
======

Edit /etc/httpd/conf/httpd.conf
Add "Listen 443" and comment out;
Listen 80
Listen 8080


# service httpd start

Starting httpd: (98)Address already in use: make_sock: could not bind to address [::]:443
(98)Address already in use: make_sock: could not bind to address 0.0.0.0:443
no listening sockets available, shutting down
Unable to open logs

I fixed the problem as follow;

Edit /etc/httpd/conf.d/ssl.conf
comment out "Listen 443"

....
#
# When we also provide SSL we have to listen to the
# the HTTPS port in addition.
#
#Listen 443
...

# service httpd start

Starting httpd:                                            [  OK  ]

https://public_ip
displays Apache default page on CentOS
(Remark - haven't setup homepage yet)


http://public_ip
displays Apache default page on Ubuntu
(Remark - haven't setup homepage yet)


http://public_ip/mail
starts SquirrelMail on Ubuntu


Now my problem is ssl httpd needs listening to port 443. I can't forward all www ports, 80, 8080 and 443 to CentOS. Because SquirrelMail on Ubuntu needs web port to run. It is a web base package.


Do you think "pound" can help me out? Any suggestion? TIA.


Others noted with thanks


Furthermore;

I'm at lost what will be the use or advantage to go virtualization? I can't run mail and web server on Host/Guest separately. What shall I make use of the Guest ? Only for testing? I think virtualization will only be suitable for running multiple public IPs.



B.R.
satimis