DO NOT REPLY [Bug 14778] New: - "Memory Leak" in XalanJ2

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http://nagoya.apache.org/bugzilla/show_bug.cgi?id=14778

"Memory Leak" in XalanJ2

           Summary: "Memory Leak" in XalanJ2
           Product: XalanJ2
           Version: 2.0.0
          Platform: PC
        OS/Version: Windows NT/2K
            Status: NEW
          Severity: Blocker
          Priority: Other
         Component: org.apache.xalan.xsltc
        AssignedTo: xalan-dev@xml.apache.org
        ReportedBy: pankaj.verma@corporate.ge.com
                CC: manindra.tiwary@corporate.ge.com


We are facing a memory leak problem while doing transformation using xalan java 
version 2. We are using templates which are cached on the server disk for the 
transformation.

Here is the sample code that we are using.

To create a template:

	public Templates getTemplate(String p_strXslUri) throws Exception {
		TransformerFactory tFactory =  TransformerFactory.newInstance();
		StreamSource stylesource = new StreamSource(p_strXslUri);
		return tFactory.newTemplates(stylesource);
	}

For debugging we printed out the instance of tFactory and it is : 
org.apache.xalan.xsltc.trax.TransformerFactoryImpl

After this,  template is put in the disk cache and used for further 
transformation.

This is the method that we use for the transformation:

    public static String transformUsingTemplates(Templates template, String 
xmlFile) throws TransformerException,
        TransformerConfigurationException, FileNotFoundException, IOException, 
Exception {
            StringWriter sos = new StringWriter();
            StreamResult streamresult = new StreamResult(sos);
            try {
                Transformer transformer = template.newTransformer();
                StreamSource XMLsource = new StreamSource(new StringReader
(xmlFile));
                transformer.transform(XMLsource, streamresult);
                return (sos.toString());
            }
            catch (Exception e) {
                throw e;
            }
    }


We tried to do a load test of the application running 25 concurrent user for 
one hour. It ran well for a while, but memory usage kept increasing and after 
some time the server stopped responding.  We ran a profiler to find out the 
bottle neck and this is the result we got.

XSLUtility.transformUsingTemplates()

Execution Count         : 4,880    
  Temporary Bytes       : 1,569,938,728  Bytes 
  Temporary Objects     : 4,055,784    
  Short-lived Bytes     : 1,569,938,728  Bytes 
  Short-lived Objects   : 4,055,784    
  Medium-lived Bytes    : 0  Bytes 
  Medium-lived Objects  : 0    
  Long-lived Bytes      : 888,751,648  Bytes 
  Long-lived Objects    : 653,812  

It�s the long lived bytes and objects that are eating up the memory. (total 15 
templates were created in the whole process)  

We are using WAS 4.0.1 AE on Win2k. Details of the jar file we are using 
(filename / size/ modified) :

Xalan.jar         886kb  2/20/2002 6:25pm
Xercesimpl.jar    1689kb 3/7/2002 10:21pm
Xml-apis.jar      106kb  2/19/2002 4:31pm
Xmlparserapis.jar 129kb  3/7/2002 10:21pm

Please let us know if there is something wrong in what we are doing or there is 
a memory leak in the transformer implementation in xalan-J2? And what is the 
resolution for this problem?