Forum Discussion
Chris_Miller
Jul 23, 2010Altostratus
Posted By hoolio on 07/23/2010 11:58 AM
Hi Chris,
What's the original use case?
Are you trying to load balance client to web VS traffic and web to app VS traffic so that the client requests are persisted to the same web and app server? If so it might be simpler and you'd get more even distribution of traffic if you used cookie insert persistence on the app VS. If the web server requests are stateful, you could persist off of the app VS persistence cookie.
Aaron
The request hits the LTM which load balances apache servers. Certain groups of apache servers have certain app instances. Using mod_weblogic on the apache boxes, traffic is sent from the apache boxes to the apps. So, number of apps indicates the processing power of a group of apache boxes. 16 app servers map to 4 specific apache servers. I'm basically persisting to these groups of apache servers, not to particular ones. The first request hits a group of all web servers (currently using least connections) and in the HTTP_RESPONSE event, I insert a cookie by comparing the IP::server_addr to a datagroup and inserting a cookie with a value that corresponds to the server group in which that box lives. The problem with doing this is that I'm treating all apache servers equal, as long as they have a single app instance, they'll pass their content health checks. I want to influence that first request load balancing algorithm by somehow including app server health.