Potential Memory Leak during Marshelling of a Web Service Response

Question

I believe I have found a memory leak when using the configuration below.
The memory leak occurs when calling a web service. When the web service function is marshelling the response of the function call, an "500 Internal Server Error ... java.lang.OutOfMemoryError" is returned from OC4J. This error may be seen via the TCP Packet Monitor in JDeveloper.
Unfortunately no exception dump is outputted to the OC4J log.
Configuration:
Windows 2000 with 1 gig ram
JDeveloper 9.0.5.2 with JAX/RPC extension installed
OC4J 10.0.3
Sun JVM version 1.4.2_03-b02
To demonstrate the error I created a simple web service and client. See below the client and web service function that demonstrates it.
The web service is made up of a single function called "queryTestOutput".
It returns an object of class "TestOutputQueryResult" which contains an int and an array.
The function call accepts a one int input parameter which is used to vary the size of array in the returned object.
For small int (less than 100). Web service function returns successfully.
For larger int and depending on the size of memory configuration when OC4J is launched,
the OutOfMemoryError is returned.
The package "ws_issue.service" contains the web service.
I used the Generate JAX-RPC proxy to build the client (found in package "ws_issue.client"). Package "types" was
also created by Generate JAX-RPC proxy.
To test the web service call execute the class runClient. Vary the int "atestValue" until error is returned.
I have tried this with all three encodings: RPC/Encoded, RPC/Literal, Document/Literal. They have the
same issue.
The OutOfMemory Error is raised fairly consistently using the java settings -Xms386m -Xmx386m for OC4J when 750 is specified for the input parameter.
I also noticed that when 600 is specified, the client seems to hang. According to the TCP Packet Monitor,
the response is returned. But, the client seems unable to unmarshal the message.
** file runClient.java
// -- this client is using Document/Literal
package ws_issue.client;
public class runClient
public runClient()
* @param args
* Test out the web service
* Play with the atestValue variable to until exception
public static void main(String[] args)
//runClient runClient = new runClient();
long startTime;
int atestValue = 1;
atestValue = 2;
//atestValue = 105; // last one to work with default memory settings in oc4j
//atestValue = 106; // out of memory error as seen in TCP Packet Monitor
// fails with default memory settings in oc4j
//atestValue = 600; // hangs client (TCP Packet Monitor shows response)
// when oc4j memory sessions are -Xms386m -Xmx386m
atestValue = 750; // out of memory error as seen in TCP Packet Monitor
// when oc4j memory sessions are -Xms386m -Xmx386m
try
startTime = System.currentTimeMillis();
Ws_issueInterface ws = (Ws_issueInterface) (new Ws_issue_Impl().getWs_issueInterfacePort());
System.out.println("Time to obtain port: " + (System.currentTimeMillis() - startTime) );
// call the web service function
startTime = System.currentTimeMillis();
types.QueryTestOutputResponse qr = ws.queryTestOutput(new types.QueryTestOutput(atestValue));
System.out.println("Time to call queryTestOutput: " + (System.currentTimeMillis() - startTime) );
startTime = System.currentTimeMillis();
types.TestOutputQueryResult r = qr.getResult();
System.out.println("Time to call getresult: " + (System.currentTimeMillis() - startTime) );
System.out.println("records returned: " + r.getRecordsReturned());
for (int i = 0; i<atestValue; i++)
types.TestOutput t = r.getTestOutputResults();
System.out.println(t.getTestGroup() + ", " + t.getUnitNumber());
catch (Exception e)
e.printStackTrace();
** file wsmain.java
package ws_issue.service;
import java.rmi.RemoteException;
import javax.xml.rpc.ServiceException;
import javax.xml.rpc.server.ServiceLifecycle;
public class wsmain implements ServiceLifecycle, ws_issueInterface
public wsmain()
public void init (Object p0) throws ServiceException
public void destroy ()
System.out.println("inside ws destroy");
* create an element of the array with some hardcoded values
private TestOutput createTestOutput(int cnt)
TestOutput t = new TestOutput();
t.setComments("here are some comments");
t.setConfigRevisionNo("1");
t.setItemNumber("123123123");
t.setItemRevision("arev" + cnt);
t.setTestGroup(cnt);
t.setTestedItemNumber("123123123");
t.setTestedItemRevision("arev" + cnt);
t.setTestResult("testResult");
t.setSoftwareVersion("version");
t.setTestConditions("conditions");
t.setStageName("world's a stage");
t.setTestMode("Test");
t.setTestName("test name");
t.setUnitNumber("UnitNumber"+cnt);
return t;
* Web service function that is called
* Create recCnt number of "records" to be returned
public TestOutputQueryResult queryTestOutput (int recCnt) throws java.rmi.RemoteException
System.out.println("Inside web service function queryTestOutput");
TestOutputQueryResult r = new TestOutputQueryResult();
TestOutput TOArray[] = new TestOutput[recCnt];
for (int i = 0; i< recCnt; i++)
TOArray[i] = createTestOutput(i);
r.setRecordsReturned(recCnt);
r.setTestOutputResults(TOArray);
System.out.println("End of web service function call");
return r;
* @param args
public static void main(String[] args)
wsmain wsmain = new wsmain();
int aval = 5;
try
TestOutputQueryResult r = wsmain.queryTestOutput(aval);
for (int i = 0; i<aval; i++)
TestOutput t = r.getTestOutputResults()[i];
System.out.println(t.getTestGroup() + ", " + t.getUnitNumber());
catch (Exception e)
e.printStackTrace();
** file ws_issueInterface.java
package ws_issue.service;
import java.rmi.Remote;
import java.rmi.RemoteException;
public interface ws_issueInterface extends java.rmi.Remote
public TestOutputQueryResult queryTestOutput (int recCnt) throws java.rmi.RemoteException;
** file TestOutputQueryResult.java
package ws_issue.service;
public class TestOutputQueryResult
private long recordsReturned;
private TestOutput[] testOutputResults;
public TestOutputQueryResult()
public long getRecordsReturned()
return recordsReturned;
public void setRecordsReturned(long recordsReturned)
this.recordsReturned = recordsReturned;
public TestOutput[] getTestOutputResults()
return testOutputResults;
public void setTestOutputResults(TestOutput[] testOutputResults)
this.testOutputResults = testOutputResults;
** file TestOutput.java
package ws_issue.service;
public class TestOutput
private String itemNumber;
private String itemRevision;
private String configRevisionNo;
private String testName;
private String testConditions;
private String stageName;
private String testedItemNumber;
private String testedItemRevision;
private String unitNumber;
private String testStation;
private String testResult;
private String softwareVersion;
private String operatorID;
private String testDate; // to be datetime
private String comments;
private int testGroup;
private String testMode;
public TestOutput()
public String getComments()
return comments;
public void setComments(String comments)
this.comments = comments;
public String getConfigRevisionNo()
return configRevisionNo;
public void setConfigRevisionNo(String configRevisionNo)
this.configRevisionNo = configRevisionNo;
public String getItemNumber()
return itemNumber;
public void setItemNumber(String itemNumber)
this.itemNumber = itemNumber;
public String getItemRevision()
return itemRevision;
public void setItemRevision(String itemRevision)
this.itemRevision = itemRevision;
public String getOperatorID()
return operatorID;
public void setOperatorID(String operatorID)
this.operatorID = operatorID;
public String getSoftwareVersion()
return softwareVersion;
public void setSoftwareVersion(String softwareVersion)
this.softwareVersion = softwareVersion;
public String getStageName()
return stageName;
public void setStageName(String stageName)
this.stageName = stageName;
public String getTestConditions()
return testConditions;
public void setTestConditions(String testConditions)
this.testConditions = testConditions;
public String getTestDate()
return testDate;
public void setTestDate(String testDate)
this.testDate = testDate;
public String getTestName()
return testName;
public void setTestName(String testName)
this.testName = testName;
public String getTestResult()
return testResult;
public void setTestResult(String testResult)
this.testResult = testResult;
public String getTestStation()
return testStation;
public void setTestStation(String testStation)
this.testStation = testStation;
public String getTestedItemNumber()
return testedItemNumber;
public void setTestedItemNumber(String testedItemNumber)
this.testedItemNumber = testedItemNumber;
public String getTestedItemRevision()
return testedItemRevision;
public void setTestedItemRevision(String testedItemRevision)
this.testedItemRevision = testedItemRevision;
public String getUnitNumber()
return unitNumber;
public void setUnitNumber(String unitNumber)
this.unitNumber = unitNumber;
public int getTestGroup()
return testGroup;
public void setTestGroup(int testGroup)
this.testGroup = testGroup;
public String getTestMode()
return testMode;
public void setTestMode(String testMode)
this.testMode = testMode;

Answer 1

I use web services a lot and I sympathize with your issue. I
struggle with similar issues and I found this great utility that
will help you confirm if your webservice is returning the data
correctly to Flex. I know you said it works in other applications
but who knows if flex is calling it correctly etc. This utility is
been the most amazing tool in helping me resolve web service
issues.
http://www.charlesproxy.com/
Once you can confirm the data being returned is good you can
try several things in flex. Try changing your result format to
object or e4x etc. See how that plays out. Not sure where your
tapping in to look at your debugger, you might want to catch it
right at the result handler before converting to any collections. .
If nothing here helps maybe post some code to look at. .
.