HELP! Database Operation in more than one thread

bennyfong · **Joined:** Tue Jan 13, 2004 1:37 am **Posts:** 11

AppServer：jboss3.1
Database: oracle 8.1.7
HIbernate：2.1

** Transaction modle use Hibernate JTA.
See Hibernate Config file:

<property name="connection.datasource">java:OracleDS</property>
<property name="dialect">net.sf.hibernate.dialect.OracleDialect</property>

<property name="show_sql">false</property>
<property name="connection.isolation">3</property>
<property name="use_outer_join">true</property>
<property name="jdbc.batch_size">10</property>
<property name="jdbc.fetch_size">100</property>
<property name="hibernate.jdbc.use_streams_for_binary">true</property>
<property name="transaction.factory_class">net.sf.hibernate.transaction.JTATransactionFactory</property>
<property name="transaction.manager_lookup_class">net.sf.hibernate.transaction.JBossTransactionManagerLookup</property>
<property name="query.substitutions">true 1, false 0, yes 'Y', no 'N'</property>

** EJB will take transaction control, such as commit database.

** There are two thread call the function named addData():
in addData(): there are two operation, the one is delete from database--call a(), the other is insert into database again--call b().
When running under two thread, problem occoured, one thread insert faild. Checking log file, database report --disobey uini-key constrain.
It seems that transaction not work,the order should be
a()-a()-b()-b(), but now it a()-b()-a()-b(). it works alternate.

Try: change addData() by using JDBC , it is no problem.
Try: change hibernate.connection.isolation level, no any help

who can help me deal with this problem, good will bless you!

bennyfong · **Joined:** Tue Jan 13, 2004 1:37 am **Posts:** 11

public Collection insertPosition(Collection positionInfoCollection, String userName) throws DbAccessException
{
logger.enterMethod();
Collection ret = new ArrayList();
NmsUserDAO nmsUserDAO = (NmsUserDAO) getDAODAOConst.NMSUSER_DAO);
long userId = -1;
Session sess = null;
try
{
sess = IdnSessionFactory.openSession();
if (positionInfoCollection.size() <= 0 || userName == null)
{
logger.debug("position size=" + positionInfoCollection.size() + " userName=" + userName);
throw new DbAccessException(DbAccessException.DBA_OTHER_EXCEPTION, ErrorReason.INSERT_OBJECT_FAILED_REASON);
}
else
{
userId = nmsUserDAO.selectUserIdByUserName(userName);
logger.debug("UserId=" + userId);
if (userId == -1)
{
throw new DbAccessException (DbAccessException.DBA_OTHER_EXCEPTION, ErrorReason.INSERT_OBJECT_FAILED_REASON);
}
else
{
String query = "from position in class com.idncn.mc.bo.Position where position.userId = ?";
long delNum = sess.delete(query, new Long(userId), Hibernate.LONG);
logger.debug("del num=" + delNum);
sess.flush();
for (Iterator iter = positionInfoCollection.iterator(); iter.hasNext(); )
{
PositionInfo positionInfo = (PositionInfo) (iter.next());
Position positionBo = new Position();
positionBo.setObjectId(positionInfo.getObjectId());
positionBo.setObjectType(positionInfo.getObjectType());
positionBo.setScreenX(positionInfo.getScreenX());
positionBo.setScreenY(positionInfo.getScreenY());
positionBo.setUserId(userId);
long newId = ((Long) sess.save(positionBo)).longValue();
ret.add(new Long(newId));
logger.debug("The position id is: " + newId);
}
sess.flush();
}
}
sess.close();
}
catch (DbAccessException e)
{
throw e;
}
catch (Exception e)
{
logger.error(e);
throw new DbAccessException(DbAccessException.DBA_OTHER_EXCEPTION);
}
finally
{
logger.exitMethod();
}
return ret;
}

bennyfong · **Joined:** Tue Jan 13, 2004 1:37 am **Posts:** 11

public class TestThread implements Runnable{
private int j;
public TestThread(int i) {
this.j=i;
}
public void run(){
Collection list=new ArrayList();
for (int i = 0; i < 50; i++) {
PositionInfo po = new PositionInfo();
po.setObjectId(219+i);
po.setObjectType(i+100);
po.setScreenX(168+this.j);
po.setScreenY(666+this.j);
list.add(po);
}
try{
GsDataAccessEJBHome home = getHome();
GsDataAccessEJB remote = home.create();
remote.addPosition(list,"system");
}catch(Exception e){
System.out.println("exception found="+e);
}

}
public static void main(String args[]){
//thread one
TestThread test=new TestThread(1);
Thread thread=new Thread(test);
thread.start();
//thread two
TestThread test1=new TestThread(100);
Thread thread1=new Thread(test1);
thread1.start();
TestThread test2=new TestThread(2);
Thread thread2=new Thread(test2);
thread2.start();
//thread two
TestThread test3=new TestThread(200);
Thread thread3=new Thread(test3);
thread3.start();

try{
thread.join();
thread1.join();
thread2.join();
thread3.join();
}catch(Exception e){
System.out.print("d="+e);
}
}
private GsDataAccessEJBHome getHome(){
GsDataAccessEJBHome home=null;
try {
Hashtable env = new Hashtable();
env.put(Context.PROVIDER_URL, "jnp://192.168.1.112:1099");
env.put(Context.INITIAL_CONTEXT_FACTORY,"org.jnp.interfaces.NamingContextFactory");

Context ctx=new InitialContext(env);

//look up jndi name
Object ref = ctx.lookup(GsDataAccessEJBHome.JNDI_NAME);
//look up jndi name and cast to Home interface
home = (GsDataAccessEJBHome) PortableRemoteObject.narrow(ref, GsDataAccessEJBHome.class);
}catch (Exception e) {
System.out.println("**="+e);
}
return home;
}

}

bennyfong · **Joined:** Tue Jan 13, 2004 1:37 am **Posts:** 11

bennyfong · **Joined:** Tue Jan 13, 2004 1:37 am **Posts:** 11

michael · **Posted:** Tue Jan 13, 2004 5:18 am

bennyfong wrote:

up

Please stop that, someone will answer as soon as he finds time to work through the 5 pages you posted, no need to get on our nerves!

emmanuel · **Posted:** Tue Jan 13, 2004 7:19 am

try to use batch_size=0

bennyfong · **Joined:** Tue Jan 13, 2004 1:37 am **Posts:** 11

emmanuel:
thanks,I have tried but problem still.

emmanuel · **Posted:** Wed Jan 14, 2004 5:29 am

Exact same exception ?
What does that mean 违反唯一约束条件 (QHE.AK_OBJECT_UK_POSITION) ?

bennyfong · **Joined:** Tue Jan 13, 2004 1:37 am **Posts:** 11

Yes, that's mean disorder unique key constraint on the table.

bennyfong · **Joined:** Tue Jan 13, 2004 1:37 am **Posts:** 11

use "Session.lock", lock related table when update. This problem seems OK.
But I think it is NOT the real solution. Because the system is running under
muti-client env, how I can deal with request from muti-clent user?

It seams that hibernate save the db operation request temploray, and commit it at one time.

I beg the answer.

Those ways I have tried:
1) Change batch size to 0
2) use hibernate transaction.
3) use Jboss Ejb transaction.