Hi all. I'm trying to configure a proxy_loadbalancer with sticky session. I
read
around the web and in the source code and discovered that this module expects
to
handle sticky session by re-using the user's session ID provided by the origin
server. This is different to BigIP which injects its own cookie that it keeps
track of. Apache also expects the origin server to know it is being
load-balanced and to change the session ID it creates to include a "route" that
identifies that origin server.
So for example if my origin server is Tomcat then the session cookie would be
JSESSIONID=12345... and Tomcat has to be modified to make it
JSESSIONID="12345.route1". Apache mod_proxy_loadbalancer sees this and finds
the
route1 and chooses the right origin server based on that. I also read that PHP
doesn't have the possibility of changing the cookie, but since PHP runs
typically on Apache, it is possible to modify the configuration of the origin
server to post-process the request to add it.
My problem is that I load balance a custom web server and/or IIS and we have
neither of these options available. I need the cookie to go through as
originally created and I can't change the way it gets created. So, how to do it?
I have tried to add a cookie at the proxy server, but I can't get this to only
happen when the origin server sends through its cookie. In fact if the origin
server sends an error code, the environment variable I use with SetEnvIf isn't
set correctly. I can't see how to add a cookie in a post-processing filter of
some sort either. The only ways I see to add cookies are in mod_rewrite (which
seems strange to me) and via mod_headers.
Any ideas?
Thanks,
Michael
