iRule redirect and specify what Pool to go to

It sounds like you have two FQDNs going to the VIP: "mypage.mycompany.com" and "www.mypage.mycompany.com". From your description it looks like you want the iRule to do two things:

1. Redirect all traffic from "mypage.mycompany.com" to "www.mypage.mycompany.com".
2. Select the pool "mysite_http_pool if the client requests the home page or if the path starts with "sp", and select "other_http_pool" for all other requests.

Couple of questions/remarks:

1. Do clients ever go to the home page by including the file name (e.g. "www.mypage.mycompany.com/index.html")? If so, what is the file name of the default page (e.g. "index.html")?
2. Which pool will be the default pool on the VIP?
3. Will it be a problem if the default pool takes down the VIP (since the other pool might still be healthy)?