I always get this error when I run a one-hour test. This happens at the end of the test before obtaining results :

Exception in thread "BidirectionnalConnection-RequestHandler" java.lang.OutOfMemoryError: GC overhead limit exceeded
08-Feb-2013 06:08:27 [exec] at java.util.jar.JarFile.getBytes(JarFile.java:360)
08-Feb-2013 06:08:27 [exec] at java.util.jar.JarFile.getManifestFromReference(JarFile.java:161)
08-Feb-2013 06:08:27 [exec] at java.util.jar.JarFile.getManifest(JarFile.java:148)
08-Feb-2013 06:08:27 [exec] at sun.misc.URLClassPath$JarLoader$2.getManifest(URLClassPath.java:696)
08-Feb-2013 06:08:27 [exec] at java.net.URLClassLoader.defineClass(URLClassLoader.java:228)
08-Feb-2013 06:08:27 [exec] at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
08-Feb-2013 06:08:34 [exec] at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
08-Feb-2013 06:08:34 [exec] at java.security.AccessController.doPrivileged(Native Method)
08-Feb-2013 06:08:34 [exec] at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.launcher.ControllerLauncher$MyURLClassLoader.findClass(ControllerLauncher.java:65)
08-Feb-2013 06:08:34 [exec] at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
08-Feb-2013 06:08:34 [exec] at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.controller.vc.a(vc.java:63)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.controller.vc.a(vc.java:54)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.controller.o.u.a(u.java:149)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.controller.o.u.b(u.java:660)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.controller.yc.b(yc.java:290)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.controller.yc.b(yc.java:199)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.controller.yc.a(yc.java:175)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.controller.jb.connectionClosed(jb.java:75)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.common.net.BidirectionalConnection.close(BidirectionalConnection.java:685)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.common.net.BidirectionalConnection$RequestHandlerThread.closeConnection(BidirectionalConnection.java:308)
08-Feb-2013 06:08:34 [exec] at com.neotys.nl.common.net.BidirectionalConnection$RequestHandlerThread.run(BidirectionalConnection.java:300)
08-Feb-2013 06:13:47 [exec] Exception in thread "MonitoringEngine-connection-system-NeoLoad" java.lang.OutOfMemoryError: GC overhead limit exceeded
08-Feb-2013 06:13:47 [exec] at com.neotys.nl.controller.o.d.a.c.d(c.java:164)
08-Feb-2013 06:13:47 [exec] at com.neotys.nl.controller.o.d.a.j.b(j.java:89)
08-Feb-2013 06:13:47 [exec] at com.neotys.nl.monitor.engine.c.requestValuesUpdate(c.java:84)
08-Feb-2013 06:13:47 [exec] at com.neotys.nl.me.a.nb.run(nb.java:118)
08-Feb-2013 06:24:29 [exec] Exception in thread "PlayBack Daemon" java.lang.OutOfMemoryError: GC overhead limit exceeded
08-Feb-2013 06:24:29 [exec] at java.net.PlainSocketImpl.socketAccept(Native Method)
08-Feb-2013 06:24:29 [exec] at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:408)
08-Feb-2013 06:24:29 [exec] at java.net.ServerSocket.implAccept(ServerSocket.java:462)
08-Feb-2013 06:24:29 [exec] at java.net.ServerSocket.accept(ServerSocket.java:430)
08-Feb-2013 06:24:29 [exec] at com.neotys.nl.controller.o.b.d.run(d.java:62)