You're right that persistence doesn't seem to be required for this to work but the issue I mention above still exists. So for example:
1st Request
URL: index.php?server=web-server1
Resource: index.php
Served by: web-server1
Resource: mylogo.jpg
Served by: web-server2
Resource: index.css
Served by: web-server2
2st Request and subsequent requests (refresh)
URL: index.php?server=web-server1
Resource: index.php
Served by: web-server1
Resource: mylogo.jpg
Served by: web-server1
Resource: index.css
Served by: web-server1
I'm assuming this behavior is perhaps due to chrome and other browsers making parallel requests and thus even though I've set a pool member it doesn't honor it for all requests until I refresh a second time? If so I'm wondering if that's avoidable anyway?