Whats J2EE Clustering?
A naive question, isn’t it? But I still use some words and figures to answer it. Generally, the J2EE clustering technology includes “Load balancing” and “failover”. Figure 1: Load balancing Shown as figure 1, load balancing implies that there are many client objects which make requests to target objects concurrently. A load balancer which sits between the callers and callees can dispatch the requests to the redundant objects which have the same functions as the original one. High availability and high performance can be achieved in this way. Figure 2: Failover Shown as figure 2, failover works differently from load balancing. Sometimes, the client object will make successive method requests to a target object. If the target object fails between the requests, the failover system should detect this failure and redirect the later requests to another available object. Fault tolerance can be achieved in this way. If you want to know more about J2EE clustering, you should ask more such basic
