SWRRuleEngine.infer() method causes OutOfMemoryError: GC overhead limit exceeded

[nmerkle]

Hi,
I am using the SWRLAPI inside a simulation framework in order to infer states according to generated triples. In my simulation framework, depending on the iteration size (e.g. 1000 times), I have to call for appropriate times, the infer() method of the SWRLAPIRuleEngine. My method for this, looks like the following code:

public List<String> reasonState() {
		states.clear();
		Set<OWLObjectPropertyAssertionAxiom>myset = null;
		ruleEngine.infer();
		for (final OWLNamedIndividual ini : st.getFlattened()) {
			System.out.println(ini.getIRI().getShortForm());
			for (final Node<OWLNamedIndividual> obj : reasoner.getObjectPropertyValues(ini, pr)) {
				states.add(obj.getRepresentativeElement().getIRI().toString());
				System.out.println(obj.getRepresentativeElement().getIRI().toString());
			}
			myset = ontology.getObjectPropertyAssertionAxioms(ini);
		}
		axioms.addAll(myset);
		
		System.out.println("Axiom Count: "+ontology.getAxiomCount());
		om.removeAxioms(ontology, axioms);
		System.out.println("Axiom Count: "+ontology.getAxiomCount());
		axioms.clear();
		return states;
	} 

So this method is called more than 1000 times. and the program is getting slower and slower until it stands still. Then, after the half of iterations and the according infer() calls I get the following exception:

java.lang.RuntimeException: Cannot call method public void de.fzi.ipe.wim.vCare.simulator.WebsocketClientSession#onMessage(java.lang.String) with args: [java.lang.String]
at org.eclipse.jetty.websocket.common.events.annotated.CallableMethod.unwrapRuntimeException(CallableMethod.java:93)
at org.eclipse.jetty.websocket.common.events.annotated.CallableMethod.call(CallableMethod.java:75)
at org.eclipse.jetty.websocket.common.events.annotated.OptionalSessionCallableMethod.call(OptionalSessionCallableMethod.java:72)
at org.eclipse.jetty.websocket.common.events.JettyAnnotatedEventDriver.onTextMessage(JettyAnnotatedEventDriver.java:225)
at org.eclipse.jetty.websocket.common.message.SimpleTextMessage.messageComplete(SimpleTextMessage.java:69)
at org.eclipse.jetty.websocket.common.events.AbstractEventDriver.appendMessage(AbstractEventDriver.java:64)
at org.eclipse.jetty.websocket.common.events.JettyAnnotatedEventDriver.onTextFrame(JettyAnnotatedEventDriver.java:217)
at org.eclipse.jetty.websocket.common.events.AbstractEventDriver.incomingFrame(AbstractEventDriver.java:160)
at org.eclipse.jetty.websocket.common.WebSocketSession.incomingFrame(WebSocketSession.java:309)
at org.eclipse.jetty.websocket.common.extensions.ExtensionStack.incomingFrame(ExtensionStack.java:214)
at org.eclipse.jetty.websocket.common.Parser.notifyFrame(Parser.java:220)
at org.eclipse.jetty.websocket.common.Parser.parse(Parser.java:258)
at org.eclipse.jetty.websocket.common.io.AbstractWebSocketConnection.readParse(AbstractWebSocketConnection.java:628)
at org.eclipse.jetty.websocket.common.io.AbstractWebSocketConnection.onFillable(AbstractWebSocketConnection.java:476)
at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:540)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.OutOfMemoryError: GC overhead limit exceeded
at sun.reflect.GeneratedConstructorAccessor18.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at java.io.ObjectStreamClass.newInstance(ObjectStreamClass.java:1079)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2044)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1567)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:427)
at java.util.ArrayList.readObject(ArrayList.java:797)
at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1158)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2169)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2060)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1567)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:427)
at org.drools.core.rule.Pattern.readExternal(Pattern.java:142)
at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:2109)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2058)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1567)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:427)
at org.drools.core.rule.From.readExternal(From.java:62)
at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:2109)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2058)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1567)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:427)
at java.util.IdentityHashMap.readObject(IdentityHashMap.java:1315)
at sun.reflect.GeneratedMethodAccessor28.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1158)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2169)

What could be the reason? I guess that it has something to do with the infer() method call. On other places in my code there are no newly generated objects or unreleased references... So there is no reason to cause memory leaks or to exceed garbage collection limits.

Thanks in advance,
nmerkle

[laotao]

Was this solved? I got a similar problem.

[sinamoh]

Same problem here. After iterating for few times, I get garbage collection error (GC overhead limit exceeded). There should be a way to reset the memory.

[PG-9-9]

Any solution so far?