Oracle WebLogic Server 10.3 and Oracle Real Application Clusters (RAC)
High availability and scalability has always been the focus in different systems enabling the customer scenarios with cost efficient solutions. There are various known issues in a heterogeneous complex environment involving JEE middle tier and the backend database. For example, the application requests may get blocked for a long period when a database node dies. There's no easy way to tell whether to obtain a fresh new connection after an application received the SQLException. The middle tier applications are unaware of new or restarted database nodes or it executes the work on a slow, hung or dead database node. Often it has to rely on waiting for TCP/IP time-outs.