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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>> > on
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>> >
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>> > [email protected]
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>> >
>>
>>
>>
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> on
> what you do best, core application coding. Discover what's new with
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