 | | | Performance problem under load - Xerces with Weblogic 9.x | Performance problem under load - Xerces with Weblogic 9.x 2007-06-29 - By Michael Glavassevich
Hi Rajesh,
If the documents you're parsing refer to the same schema documents you can
significantly improve the performance by doing grammar caching. The JAXP
1.3 validation API [1] provides a standard mechanism for doing this.
Thanks.
[1]
http://xerces.apache.org/xerces2-j/javadocs/api/javax/xml/validation/package
-summary.html
Michael Glavassevich
XML Parser Development
IBM Toronto Lab
E-mail: mrglavas@(protected)
E-mail: mrglavas@(protected)
"Rajesh Balamohan" <rajesh.balamohan@(protected)> wrote on 06/29/2007
04:57:13 AM:
> Hello Folks,
>
> We are using xerces parser for creating DOM objects. The size of the
> xml is very small in the order or 1 or 2kb. Under load, most of the
> threads in weblogic are blocked like the following.
>
> And the CPU of the box is at 98% in a 4 way box. Looking at the
> stacktrace below, I find that most of the time is spent in schema
> loading. There are lots of threads with similar stack trace. Are
> there any known workarounds for this problem?.
>
> Is there a way to improve the XMLSchemaLoader?
>
> The options we use during XML parser creation is as follows.. (Any
> help on this issue would be of great help folks).
>
> // Build a parser to order.
> p = new DOMParser();
> p.setFeature("http://xml.org/sax/features/validation
> ", true);
> p.setFeature ("http://apache.
> org/xml/features/validation/schema", true);
> p.setFeature(" http://apache.
> org/xml/features/validation/schema/normalized-value", false);
> p.setFeature("http://apache.
> org/xml/features/dom/defer-node-expansion ", false);
>
> p.setEntityResolver(this);
> p.setErrorHandler(this);
>
> "[ACTIVE] ExecuteThread: '12' for queue: 'weblogic.kernel.Default
> (self-tuning)'" daemon prio=6 tid=0x54777e60 nid=0x138
> 0 waiting for monitor entry [0x544bf000..0x544bfb9c]
> at java.util.Hashtable.get(Hashtable.java:335)
> - waiting to lock <0x0c54f0f8> (a java.util.Hashtable)
> at org.apache.xerces.impl.xs.traversers.XSAttributeChecker.
> checkAttributes (Unknown Source)
> at org.apache.xerces.impl.xs.traversers.XSAttributeChecker.
> checkAttributes(Unknown Source)
> at org.apache.xerces.impl.xs.traversers.
> XSDWildcardTraverser.traverseAny(Unknown Source)
> at org.apache.xerces.impl.xs.traversers.
> XSDAbstractParticleTraverser.traverseSeqChoice(Unknown Source)
> at org.apache.xerces.impl.xs.traversers.
> XSDAbstractParticleTraverser.traverseSequence(Unknown Source)
> at org.apache.xerces.impl.xs.traversers.
> XSDComplexTypeTraverser.processComplexContent(Unknown Source)
> at org.apache.xerces.impl.xs.traversers.
> XSDComplexTypeTraverser.traverseComplexTypeDecl(Unknown Source)
> at org.apache.xerces.impl.xs.traversers.
> XSDComplexTypeTraverser.traverseGlobal(Unknown Source)
> at org.apache.xerces.impl.xs.traversers.XSDHandler.
> getGlobalDecl(Unknown Source)
> at org.apache.xerces.impl.xs.traversers.XSDElementTraverser.
> traverseNamedElement (Unknown Source)
> at org.apache.xerces.impl.xs.traversers.XSDElementTraverser.
> traverseGlobal(Unknown Source)
> at org.apache.xerces.impl.xs.traversers.XSDHandler.
> traverseSchemas(Unknown Source)
> at org.apache.xerces.impl.xs.traversers.XSDHandler.
> parseSchema(Unknown Source)
> at org.apache.xerces.impl.xs.XMLSchemaLoader.
> loadSchema(Unknown Source)
> at org.apache.xerces.impl.xs.XMLSchemaValidator.
> findSchemaGrammar (Unknown Source)
> at org.apache.xerces.impl.xs.XMLSchemaValidator.
> handleStartElement(Unknown Source)
> at org.apache.xerces.impl.xs.XMLSchemaValidator.
> startElement(Unknown Source)
> at org.apache.xerces.impl.XMLNSDocumentScannerImpl.
> scanStartElement (Unknown Source)
> at org.apache.xerces.impl.
> XMLNSDocumentScannerImpl$NSContentDispatcher.
> scanRootElementHook(Unknown Source)
> at org.apache.xerces.impl.
> XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch
> (Unknown Source)
> at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.
> scanDocument(Unknown Source)
> at org.apache.xerces.parsers.XML11Configuration.parse(Unknown
Source)
> at org.apache.xerces.parsers.XML11Configuration.parse (Unknown
Source)
> at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
> at org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
>
> --
> ~Rajesh.B
---------------------------------------------------------------------
To unsubscribe, e-mail: j-dev-unsubscribe@(protected)
For additional commands, e-mail: j-dev-help@(protected)
|
|
|