There is either a leak: The application keeps pointers to a lot of objects that are actually never going to be used. Or running out of memory: The application

There is either a leak: The application keeps pointers to a lot of objects that are actually never going to be used. Or running out of memory: The application keeps pointers to objects that will be used later. Both problems are solvable, you remove the pointers or change the algorithm respectively. (If you simply can't add more memory.) The real hard problem is that the jvm takes a long time to report an OOM error. But it's not unique to java; Who have not seen servers that have become unresponsive in a low memory situation.