Three Fragment Caching Questions

Rails
1

Hi,

I have three questions and would love answers to any of them:

  1. Can I use fragment caching on a layout?

  2. How can I expire fragments using script/runner. Code would be
    helpful here, I see hints online but none of it is complete.

  3. When I enabled fragment caching in a web app there was a strange bug
    so that if users when to “site.com” everything worked fine, but if
    users went to “www.site.com” the layout was repeated twice around the
    dynamic content. The web server was lighttpd.

Again answers to any of these questions would be helpful.

-Scott