you are using 32bit jdk(jdk1.4) which wouldn't be able to allocate more than 2GB memory,if your application needs more memory try to use 64bit jdk(like jRockit 1.5 x64 ,jRockit1.6 x64) and WebLogic9.2 or weblogic10 x64 on x64 OS platform. besides don't forget to tune gc.