Is JVM ARGS '-Xms1024m -Xmx2048m' still useful in Java 8?

Question

I have a Java 7 application using JVM ARGS: -Xms1024m -Xmx2048m, and it runs pretty well.

After I upgrade to Java 8, it runs in error state with Exception:

Exception in thread "main" java.lang.OutOfMemoryError: GC overhead limit exceeded     at org.hibernate.engine.StatefulPersistenceContext.addEntry(StatefulPersistenceContext.java:466)     at org.hibernate.engine.TwoPhaseLoad.postHydrate(TwoPhaseLoad.java:80)     at org.hibernate.loader.Loader.loadFromResultSet(Loader.java:1439)     at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1332)     at org.hibernate.loader.Loader.getRow(Loader.java:1230)     at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:603)     at org.hibernate.loader.Loader.doQuery(Loader.java:724)     at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)     at org.hibernate.loader.Loader.doList(Loader.java:2228)     at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)     at org.hibernate.loader.Loader.list(Loader.java:2120)     at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:118)     at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1596)     at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:306) 

I'm wondering whether JVM ARGS -Xms1024m -Xmx2048m is still working?

Since Java 8 has removed Perm Generation: http://www.infoq.com/articles/Java-PERMGEN-Removed, I think the different GC strategy/memory management between Java 7 and Java 8 may be the root cause. Is there any suggestion?

Answer 1

Due to PermGen removal some options were removed (like -XX:MaxPermSize), but options -Xms and -Xmx work in Java 8. It's possible that under Java 8 your application simply needs somewhat more memory. Try to increase -Xmx value. Alternatively you can try to switch to G1 garbage collector using -XX:+UseG1GC.

Note that if you use any option which was removed in Java 8, you will see a warning upon application start:

$ java -XX:MaxPermSize=128M -version Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=128M; support was removed in 8.0 java version "1.8.0_25" Java(TM) SE Runtime Environment (build 1.8.0_25-b18) Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)