I spoke with Chris about this today and he told me he's got some experience making requests redirect to different backend nodes under certain conditions. We're going to test this out today to make sure it works before going to production.

i have added the following rule to test this out (and saved it as aus4-to-aus3 as a zeus traffic script rule). currently, it only works when a header of cturra: true is passed. if ( http.getHeader("cturra") == "true" ) { if (http.getHeader("Host") == "aus4.mozilla.org") { pool.select("aus2_81"); } } i have also validated that this does not result in any issues with ssl termination since it doesn't change how the load balancer does this - it just proxies the requests through to a different backend pool. $ curl -I https://aus4.mozilla.org -H "cturra:true" HTTP/1.1 403 Forbidden Server: Apache X-Backend-Server: pp-app-dist02 Content-Type: text/html; charset=iso-8859-1 Date: Wed, 25 Sep 2013 18:28:32 GMT Transfer-Encoding: chunked Connection: Keep-Alive

turns out all requests with the above traffic rule were returning http 403s because we needed up update the host header. a working rule appears to be (note, i have also tripped the cturra:true header check now for testing): if (http.getHeader("Host") == "aus4.mozilla.org") { http.setHeader("Host", "aus3.mozilla.org"); pool.select("aus2_81"); }

This is looking OK to me, too. Nick, do you want to poke at it all?

Looks good. It's great to have this safety net already scoped out before deployment.

i am going to mark this as r/fixed since the rule is in place and our testing all looks positive. :bhearsum - ping me on irc when you want this traffic rule disabled on aus4. do note however, i will be keeping it applied but disabled so we can react very quickly if it's needed \o/