Suppose I have a website hosted at the url:
Say this is hosted by hosting provider "A".
Now, I want to host a subdirectory within this site at another host:
...say I host this with hosting provider "B". So all the pages under this site would be at a completely different data center.
Is this configuration possible?
If you can configure a reverse proxy... then yes.
IIS reverse proxy <= is is a codeproject solution and may not have support. You can probably find many more if you just search for reverse proxy.
If you are using IIS7 (Vista, Windows 7, Server 2008) you may use the HTTP Redirect feature that is built in.
Point the DNS record for the subdomain to the ip address of the other host.
Yes, entirely possible.
Recently I came across this exact problem, using IIS. For our solution we used ISAPI_Rewrite 3.
You can use a simple directive in IIS with ISAPI_Rewrite 3 and the RewriteProxy directive
If you are using Apache mod proxy will work, (mentioned already here). Unfortunately there's no equivalent of RewriteProxy in Apache mod rewrite.
One caveat of this solution we had was to make some rewrite rules to handle the new url's to blog posts.
You'll need a sqiud server in front of both apaches for optimal results. All the requests will come to the squid instance, which will route it to the right apache based on request path.
Both apaches will have to be configured for that domain. DNS A record must point to the Squid instance.