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();
> > }
> > }
> > }
> >
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> >
>
>
>
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