Advanced WebLogic Cluster
Use this architecture only if you cannot use the Generic Webserver Cluster discussed in a following section. This architecture improves the Simple WebLogic cluster by removing the single point of failure of the WebLogic proxy server. High Availability is achieved by using a load balancer.
For this setup:
Use WebLogic proxy serving HttpClusterServlet web application.
Use Loadbalancer with loadbalancer-cookie based session sticky for HTTP and SSL based
session sticky for HTTPS
All instances must use the same HTTP/HTTPS port e.g. 5010/5011 in the example. This requires
IP Aliasing if the host does not have dedicated network interfaces for each webserver instance
One proxy server load balances across all the WebLogic instances on that host only, so you will
use a different multicast address for each host in the cluster
The proxy will only pass all calls to the webserver instances.
WebLogic proxy server and WebLogic servers providing PIA are run as WebLogic Managed
Servers
Advantages:
Good Scalability
Good fault tolerance
Good flexibility of adding/removing servers dynamically
Works with non identical webhosts
Disadvantages:
Proxy adds an additional layer
WebLogic proxy requires IP Aliasing for running multiple instances
Reasonably complex to setup
