Hi Michele, Charles,
It's very likely there is a bug in deadlock resolution in Sedna. I've
reproduced this situation and we are working to find out exact reason. I'll
give you know about our results.
Ivan Shcheklein,
Sedna Team
On Wed, Jul 29, 2009 at 4:11 PM, Charles Foster <[email protected]> wrote:
> Ok, I will investigate this more thorougly when I have time, in the mean
> time to fix your problem please refer to the Sedna XML:DB API
> documentation about how to not have Database Connections recycled etc.
>
> Charles
>
> > Hi Charles,
> > Thank for the response,
> > as you suggest to me, I have repeated the test using the sedna driver;
> > below there is the code that I've used for new test.
> >
> > With this code it can load 20 resources simultaneously.
> >
> >
> > In the test with the Sedna XML:DB API I have tried to eliminate the row
> of
> > code where I close the collection
> > (in tis manner I never use a "recycled" Database Socket connection) and
> so
> > there are no problems.
> >
> > It seems that the problem occurs when I use "recycled" collection.
> >
> > Code with sedna driver
> > import ru.ispras.sedna.driver.*;
> > public class Test2 {
> > public Test2() {
> > removeAll();
> > int numThread = 20;
> > final Thread[] listThread = new Thread[numThread];
> > for (int i = 0; i < numThread; i++) {
> > final int count = i;
> > listThread[i] = new Thread(new Runnable() {
> > public void run() {
> > SednaConnection conn = getConnection();
> > try {
> > conn.begin();
> > SednaStatement st1 = conn.createStatement();
> > boolean call_res = st1.execute("LOAD
> > \"c:\\test.xml\" \"a" + count + "\"");
> > conn.commit();
> > } catch (Exception e) {
> > try {
> > conn.rollback();
> > } catch (DriverException e1) {
> > e1.printStackTrace();
> > }
> > System.out.println(e);
> > } finally {
> > try {
> > conn.close();
> > } catch (DriverException e) {
> > e.printStackTrace();
> > }
> > }
> >
> > }
> >
> > });
> >
> > }
> > long ini = System.currentTimeMillis();
> > for (int i = 0; i < numThread; i++) {
> > listThread[i].start();
> > }
> >
> > for (int i = 0; i < numThread; i++) {
> > try {
> > listThread[i].join();
> > } catch (InterruptedException e) {
> > e.printStackTrace();
> > }
> > }
> > System.out.println("fine totale:" + (System.currentTimeMillis() -
> > ini));
> > }
> >
> > private SednaConnection getConnection() {
> > SednaConnection con = null;
> > String url = "localhost";
> > String dbname = "Test";
> > String user = "SYSTEM";
> > String password = "MANAGER";
> > try {
> > con = DatabaseManager.getConnection(url, dbname, user,
> > password);
> > } catch (DriverException e) {
> > e.printStackTrace();
> > }
> > return con;
> > }
> >
> > ...
> >
> > public static void main(String[] args) {
> > Test2 t2 = new Test2();
> > }
> > }
> >
> >
> >
> >
> >
> >
> > 2009/7/28 Charles Foster <[email protected]>
> >
> >> Hi Michele,
> >>
> >> I've spoken to you about this before privately and explained to you that
> >> investigating this problem would take a long time indeed.
> >>
> >> It appears that the code creates 10 concurrent connections and "open
> >> transactions" on the database at the same time.
> >>
> >> Have you tried opening 10 connections with an according 10 concurrent
> >> OPEN-transactions on the Database with either Sedna Team MODIS Driver or
> >> even se_term? Or even getting the same thing to work with the Team MODIS
> >> Java driver?
> >>
> >> Are you aware that the following code:
> >>
> >> DatabaseManager.getCollection(String, String, String)
> >>
> >> will create you a brand new Sedna Connection / Socket?
> >>
> >> Please investigate as much as you can about this and identifying where
> >> the
> >> issue resides (Sedna XML Database or Sedna XML:DB Driver), The fact the
> >> error message is SEDNA Message: ERROR SE4703... would suggest it is at
> >> the
> >> Server end, but please first find this out.
> >>
> >> Regards,
> >>
> >> Charles
> >>
> >> > Hi,
> >> >
> >> > I've encountered a problem when I try to use a Sedna XML:DB API for
> >> Java
> >> > in
> >> > a multithreading application.
> >> >
> >> > When more than one thread try to store a different resource in the
> >> same
> >> > collection and the operation is bounded in one transaction I get the
> >> > following error:
> >> >
> >> > SEDNA Message: ERROR SE4703 The transaction is a victim of deadlock
> >> > resolution procedure.
> >> >
> >> > This is the test code for replicate the problem:
> >> >
> >> >
> >> >
> >> >
> >> > import org.xmldb.api.DatabaseManager;
> >> > import org.xmldb.api.base.Collection;
> >> > import org.xmldb.api.base.Database;
> >> > import org.xmldb.api.base.Resource;
> >> > import org.xmldb.api.base.XMLDBException;
> >> > import org.xmldb.api.modules.CollectionManagementService;
> >> > import org.xmldb.api.modules.TransactionService;
> >> > import org.xmldb.api.modules.XMLResource;
> >> >
> >> > public class Test3 {
> >> > public Test3() throws Exception {
> >> >
> >> > Database sednaDatabase;
> >> > Class<?> clazz = Class.forName("net.cfoster.sedna.DatabaseImpl");
> >> > sednaDatabase = (Database) (clazz.newInstance());
> >> > DatabaseManager.registerDatabase(sednaDatabase);
> >> >
> >> > int numThread = 10;
> >> > final Thread[] listThread = new Thread[numThread];
> >> >
> >> > for (int i = 0; i < numThread; i++) {
> >> >
> >> > final int count = i;
> >> >
> >> > listThread[i] = new Thread(new Runnable() {
> >> > public void run() {
> >> > Collection root = null;
> >> > TransactionService transactionService = null;
> >> > try {
> >> > root =
> >> > DatabaseManager.getCollection("xmldb:sedna://localhost:5050/Test",
> >> > "SYSTEM",
> >> > "MANAGER");
> >> > transactionService = (TransactionService)
> >> > root.getService("TransactionService", "1.0");
> >> > transactionService.begin();
> >> > Resource r = root.createResource("test" + count,
> >> > XMLResource.RESOURCE_TYPE);
> >> > r.setContent("<test/>");
> >> > root.storeResource(r);
> >> > transactionService.commit();
> >> > } catch (Exception e) {
> >> > e.printStackTrace();
> >> > try {
> >> > transactionService.rollback();
> >> > } catch (XMLDBException e1) {
> >> > e1.printStackTrace();
> >> > }
> >> > } finally {
> >> > try {
> >> > root.close();
> >> > } catch (Exception e) {
> >> > e.printStackTrace();
> >> > }
> >> > }
> >> >
> >> > }
> >> >
> >> > });
> >> >
> >> > }
> >> > System.out.println("init");
> >> > for (int i = 0; i < numThread; i++) {
> >> > listThread[i].start();
> >> > }
> >> >
> >> > for (int i = 0; i < numThread; i++) {
> >> > listThread[i].join();
> >> > }
> >> > System.out.println("end");
> >> > System.exit(0);
> >> > }
> >> >
> >> >
> >> >
> >> > public static void main(String[] args) {
> >> > try {
> >> > new Test3();
> >> > } catch (Exception e) {
> >> > e.printStackTrace();
> >> > }
> >> > }
> >> > }
> >> >
> >>
> ------------------------------------------------------------------------------
> >> > Let Crystal Reports handle the reporting - Free Crystal Reports 2008
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> >> > trial. Simplify your report design, integration and deployment - and
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> >> > on
> >> > what you do best, core application coding. Discover what's new with
> >> > Crystal Reports now.
> >> >
> >>
> http://p.sf.net/sfu/bobj-july_______________________________________________
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> >> > [email protected]
> >> > https://lists.sourceforge.net/lists/listinfo/sedna-discussion
> >> >
> >>
> >>
> >>
> >>
> ------------------------------------------------------------------------------
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> >> 30-Day
> >> trial. Simplify your report design, integration and deployment - and
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> >> on
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> >
> ------------------------------------------------------------------------------
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> focus
> > on
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> >
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>
>
>
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