What are my options for load balancing with Oracle RAC? Why do I get an uneven number of connections on my instances?
All the types of load balancing available currently (9i-10g) occur at connect time. This means that it is very important how one balances connections and what these connections do on a long term basis. Since establishing connections can be very expensive for your application, it is good programming practice to connect once and stay connected. This means one needs to be careful as to what option one uses. Oracle Net Services provides load balancing or you can use external methods such as hardware based or clusterware solutions. The following options exist prior to Oracle RAC 10g Release 2 (for 10g Release 2 see Load Balancing Advisory): Random Either client side load balancing or hardware based methods will randomize the connections to the instances. On the negative side this method is unaware of load on the connections or even if they are up meaning they might cause waits on TCP/IP timeouts. Load Based Server side load balancing (by the listener) redirects connections by default depend
