Nginx reverse proxy with Weblogic - Sticky learn

[george22]

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.

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,293721,293721#msg-293721