HA cookie-based routing in the cloud

[Langley]

We are looking for a solution for "sticky bit routing" based on cookies
that will run on Amazon's EC2 cloud. 

I've looked at the sticky module (although not the source yet) and it
~may~ be capable of doing what we need, but I thought I'd ask the forum
to see if anyone else has already tried this solution. (Without knowing
the implementation, it's impossible to say if our requirements can be
met by the sticky module) 

The challenge that we have is that unlike a traditional system where the
sticky bit routing would be to one of a set of predefined servers, in
our case, the servers will be created dynamically in the cloud. We can't
"configure" them when we start the nginx routing layer. Although we may
have some "back up" servers, that can be used if no cookie is in the
request OR if the cookie specifies a server that has died, in general
the servers that the cookie will be specifying will be dynamically
created and we will assign them to the requests "ourselves" (not needing
the nginx layer to round-robin assign them to one of a pool of fixed
address servers). 

So my question may come down to: "Can the sticky module route to servers
not predefined in the initial configuration"? I can easily imagine an
implementation that could handle this, but wanted to ask if the sticky
module already does this.

Thanks in advance 

-- Langley

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,222088,222088#msg-222088