Hi

I've implemented sticky learn for my weblogic application running on 3 servers using Nginx as the reverse proxy and trying to get an understanding of how nginx sticky learn works.

The JSESSIONID cookies are of the form <session identifier>!<primary server id 1><!secondar server id 2>.

I understand that nginx learns from the 'sticky create' to determine which upstream server the request should be routed to using lookup cookie. But it is not clear from the documentation what happens when the upstream primary server is down. Will nginx route to secondary server? Based on my initial tests it looks like it does not route to the secondary server. I need confirmation if this is expected behavior. What do I need to do to route requests to secondary server if primary server is down using sticky learn?


upstream app1 {
least_conn;
zone app1 64k;
server srv1.example.com:5111;
server srv2.example.com:5111;
server srv3.example.com:5111;
sticky learn
create=$upstream_cookie_JSESSIONID
lookup=$cookie_JSESSIONID
zone=client-sessions:1m
timeout=2h;
}


Thanks.