multiple webapp running on same tomcat using same jvm. sometime, one webapp that have memory leak will cause entire jvm to crash and affect other webapps. any recommendation how to isolated that without need to use multiple jvm and tomcat
Within the same JVM everything shares the the same memory. There is no system to allocate separate pools or quota.
If one of your applications behaves really badly in this regard, the only thing you can do is run it isolated in a separate JVM (separate Tomcat).