how to get a value from upstream and redirect to another url according to the value?

[notedit]

hello 

i want to write a module , in this module  i first get  a value from the
memcache upstream , then i will redirect the url according to the value
i got?

i know how to get a value from memcache upstream,  but i don't not know
where and when  and how i  redirect to another url.

thanks for your reading .

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,191581,191581#msg-191581