Khaja Minhajuddin's questions

I have a beefy linux server (32 GB RAM) with good harddrives. with one of my hosts. I run a lot of webapps which use varnish, nginx, unicorn app server, thin app server, redis, mongodb and postgresql. Now, I don't expect a huge amount of traffic to the webapps. So, my questions is, with a good enough server, Should I just run all the services on the bare metal OS? or should I setup VMS and run a few services on the VMS? Setting up VMs doesn't seem like a good idea performance wise.

EDIT: It'd be great if someone had some numbers on this. I would never have thought of putting databases on VMs as they are more IO intensive. I don't have any numbers to support that, but wanted to know if anyone has deployed databases on VMs.

I have two rails webapps, I have configured one webapp to respond to multiple domains. I have done this by making the corresponding server block in nginx as the default.

Now, I want to make even the other webapp process requests for custom multiple domains, Is there a way to do this using a machine with a single IP address? (I know that I can add an additional IP address and make the other webapp listen on this, but my server is on EC2 so I can't add more IPs.)

Both these webapps know which domains they are supposed to respond to, and there are a lot of domains. Also, the domains which these webapps need to respond to, will be changing. So I can't hardcode them in the nginx config. My server has Ubuntu 10.04.

I've researched a bit into this and I think HAProxy may be able to do this kind of routing. Is it possible for HAProxy ACLs to access something like redis to find the destination of an http request?

I have a rackspace linux server with 512 MB of RAM and a Linux Micro instance on EC2 (it has 613 MB of RAM).

I wanted another bulkier instance for a new web app our company is deploying. I am planning to go with Amazon standard instance (which has 1.7GB memory, costs ~$10 if reserved for 3 years). A server with the same amount of RAM would cost me lots of money on Rackspace Cloud(costs $87), I don't understand why there is such a difference, Am I missing something?

Our company has created simple CMS app, which it is planning to sell to thousands of small companies. Right now, our CMS app spits out the html files to a pre-configured directory in a directory structure like:

root:
    /foo.com
    /bar.com
    /.......

Managing these websites using the virtual hosts is not practical, Right now, we are using a simple rack module which finds the right files based on the HTTP_HOST and returns the appropriate html by reading the file from the hard-drive. This is obviously not an optimal solution.

What would you guys do to solve this?