Comment 8 for bug 670013

On Thu, Nov 4, 2010 at 6:58 AM, Gary Poster <email address hidden> wrote:
> Thank you, Leonard.
>
> To follow on with comment 5, Leonard and I don't think that a naive
> forwarding of edge to production will work.

I'm curious what we're anticipating as failures.

> Moreover, we're skeptical that simply serving adjusted WADL will be sufficient.

Does the WADL have the hostname in it?

> Zope typically handles virtual hosts such that the same process can
> respond to requests from different vhosts with the same results, except
> maintaining links within the requested vhost.  I don't know if Launchpad
> still is capable of this, or if it has been customized out of that
> functionality, but I'm cautiously optimistic that it would be workable.

Its definitely possible - after all we serve 6 or so vhosts today. We
may hit friction in canonical_url though.

> If it were, we have the only fully backwards-compatible solution we've
> identified so far: edge.launchpad.net (and friends, like
> edge.code.launchpad.net and so on) live on as vhosts against the
> production server, and Launchpad simply keeps URLs (including WADL,
> which would have to be handled specially) within the requested vhost.
> This is probably mostly a canonical_url dance, within the LP codebase.

I'd like a plan that eventually fades to no overhead.

If I understand correctly, this is where we are at:
 - no launchpadlib versions in Ubuntu releases use edge by default
 - apps build on launchpadlib may be using edge (and in fact some probably are)
   - so lets look at the lplib usage data to identify those - so we
can estimate their impact and disappearance.
 - redirects won't work
 - rewrites in apache probably won't work
 - zope appserver changes may work

Another approach is just to shrink the edge cluster as rapidly as we
can, with a redirect for non-apis.

-Rob