Is there an advantage to using a subdomain over a virtual directory?

Question

Here is my situtation: I have domainname.com pointing to a server that currently has one static IP address. The server is running Win2008 Std and is currently hosting our only application.

The application allows uploading image files and we then join those to create small MP4 video files (you can think of the uploaded images as frames for the video). Those files are then played on a web page along with a static video that allows for streaming (we are using this streaming module for IIS 7 to get the job done).

Currently, we have a separate disk drive whose sole purpose is to host the media files. Right now we have a virtual directory pointing to the other drive and the application thinks this is merely a folder within its own folder structure.

Essentially, question is this: would I gain any performance advantage at all by configuring a subdomain instead of using the virtual directory? I am fairly ignorant of the finer details of DNS and running full-blown application servers, thus my question. If I needed to, I could get another IP address for this machine, but I don't know if that helps either.

Any advice is appreciated, thanks.

Answer 1

Performance wise for DNS there isn't any real difference between a vdir or separate site (with a subdomain). A separate site will require an extra DNS lookup but the impact is negligible.

IIS itself will also serve both up equally fast. Well, again, slight differences not worth counting ... if you have each in their own app pool it could take a brief few seconds longer to load on the first hit.

With 2 different sites you do have some isolation between them in case one isn't as stable then the other can continue to run, so that is always a consideration. You can also create separate security sandboxes between the two sites.

The biggest question is more of housekeeping and deployment. If you want the two to be deployed separately sometimes, or if you want to isolate them into their own roles, then separate sites makes more sense.

Scalability is another reason you may consider two separate sites. Rather than scaling up to a larger server or webfarm, you could separate them into different servers/farms with a different domain name. Mind you, you can do that with many load balancers too.

So, the answer is really that it depends. Both methods are fully acceptable and my guess is that you could go down either path and it would work well for you.