home list archives users mailing list
 

Subject: Tomcat OutOfMemoryError with OGSA-DAI clients

Date view Thread view Subject view Author view Attachment view

From: Lucas Zamboulis (lucas@dcs.bbk.ac.uk)
Date: May 12, 2006 21:30

Hi,

I'm having trouble retrieving a 200,000 integer result set from a MySQL
database. I'm using OGSA-DAI WSI 2.1 on a Linux FC4 with 2GB RAM. I
successfully retrieve data from other tables in the same DB (and from
the same table when e.g. adding an Id<1000 constraint on the query).
This is therefore a problem having to do with the size of the result
set: both databrowser and end-to-end client exit with an
OutOfMemoryError, although the Tomcat log (see end of mail) .

I then read the related issue in the DAI FAQ, which suggests:

- increase the memory heap size for the virtual machine using the
Xms<size> flag.
--- Done that, raised both Xms and Xmx flags in the catalina.sh file,
using both CATALINA_OPTS and JAVA_OPTS, problem persists

- may be a JDBC driver issue for specific db (loading whole results set
in memory prior to giving a handle to DAI), try using another DBMS
--- Using the latest driver, DBMS: MySQL version 4.1.

- Try using asynchronous data transport functionalty to stream the data
to and from the service in chunks
--- I'm actually trying to use DQP over DAI, so it's out of my control,
but as I understand it, DQP 3 does use asynchronous data transport
functionalty and I still get an error when issuing the same query on DQP
(that's how I first noticed the problem - although the problem appears
in a different manner when using DQP).

Do you think the error I'm getting is because neither the databrowser,
nor the end-to-end client use asynchronous data transport? I'm asking
because the start of the log file (showing all three DAI process to have
completed successfully) implies that DAI successfully processed the
query and the result set, and therefore the error may be in the
application using DAI.

If not, any ideas?

Regards,
Lucas

-----------------------------------------------------------------------
Lucas Zamboulis
R.A./Ph.D. candidate
School of Computer Science and Information Systems
Birkbeck College, University of London
London Knowledge Lab Tel.: +44 20 7763 2102
23-29 Emerald Street Fax: +44 20 7242 2756
London, WC1N 3QS http://www.dcs.bbk.ac.uk/~lucas

May 12, 2006 9:17:33 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 4814 ms
- statementOutputStatus : PROCESSING
- statementRSToXMLStatus : PROCESSING
- statementStatus : PROCESSING
- statementStatus : COMPLETED
- statementRSToXMLStatus : COMPLETED
- statementOutputStatus : COMPLETED
- java.io.IOException:
ClientAbortException: java.net.SocketException: Connection reset
        at
org.apache.coyote.tomcat5.OutputBuffer.realWriteBytes(OutputBuffer.java:373)
        at org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:294)
        at org.apache.coyote.tomcat5.OutputBuffer.writeBytes(OutputBuffer.java:401)
        at org.apache.coyote.tomcat5.OutputBuffer.write(OutputBuffer.java:388)
        at
org.apache.coyote.tomcat5.CoyoteOutputStream.write(CoyoteOutputStream.java:76)
        at org.apache.axis.utils.ByteArray.writeTo(ByteArray.java:375)
        at org.apache.axis.SOAPPart.writeTo(SOAPPart.java:265)
        at org.apache.axis.Message.writeTo(Message.java:528)
        at
org.apache.axis.transport.http.AxisServlet.sendResponse(AxisServlet.java:902)
        at org.apache.axis.transport.http.AxisServlet.doPost(AxisServlet.java:777)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
        at
org.apache.axis.transport.http.AxisServletBase.service(AxisServletBase.java:327)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
        at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
        at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
        at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at
org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
        at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
        at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
        at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
        at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
        at
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
        at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
        at java.lang.Thread.run(Thread.java:534)

Date view Thread view Subject view Author view Attachment view