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neo

Joined: 10/06/2009 08:12:36
Messages: 7
Location: Colombia
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Hi

Here's an example of test that reproduces the problem we've been having.

As they realize the problem can be seen most clearly when there are multiple sessions and threads running.

public static void testGetEmployeeWithThreads(){
EhCacheTestThread thread1 = new EhCacheTestThread();
thread1.setName("T1");
EhCacheTestThread thread2 = new EhCacheTestThread();
thread2.setName("T2");
EhCacheTestThread thread3 = new EhCacheTestThread();
thread3.setName("T3");
EhCacheTestThread thread4 = new EhCacheTestThread();
thread4.setName("T4");

System.out.println("Start t1");
thread1.start();
System.out.println("Start t2");
thread2.start();
System.out.println("Start t3");
thread3.start();
System.out.println("Start t4");
thread4.start();

}

I use the class EhCacheTestThread with the following method:

public void run() {

testGetEmployee();
}

/**
* Generic test with get employees.
* @author Juan Morales
*/
public void testGetEmployee(){
List<Long> employeeKeys = null;
Session session = null;

String sql = "select employee_key from employee";
employeeKeys = intHibernateUtil.getCurrentSession().createSQLQuery(sql)
.addScalar("employee_key", Hibernate.LONG)
.list();

while(true){
session = HibernateUtil.createSession();
try{
for(Long key : employeeKeys){
session.get(DBEmployee.class,key);

}

session.close();
sleep(1000);
}catch(Exception e){
session.close();
e.printStackTrace();

}

}

}

You can see the state of the threads with Jconsole and the hibernate queries
in the java output console

we appreciate if you can help us.
thanks beforehand.

juanux

Neo

1. What exactly is the problem?
2. I think you are missing some files that you meant to attach

Greg

Oh, also, what version of ehcache and Hibernate are you taking about?

the problem is that although the Employee table is in the second level cache, running these code you can be seen in the consolea big lot of hibernate queries from this table.

we´re using ehcache 1.7 and hibernate 3.

we have the following configuration:

<cache name="mint.hibernate.bean.MintDBEmployee"
maxElementsInMemory="30000"
eternal="true"
overflowToDisk="false"
>

</cache>

We using ehcache as part of the core of our system
we appreciate if you can help us with it.
thank u so much

I see most of your example use are using createSQLQuery.

Firstly can you please rerun your tests against ehcache-1.5 and report the results.

If the issue is still there it is not an ehcache issue. You may be seeing a Hibernate bug http://opensource.atlassian.com/projects/hibernate/browse/HHH-2470

Can I also see your ehcache.xml?

Another thing. See http://74.125.95.132/search?q=cache:jfMvhPgRyi8J:i-proving.ca/space/Technologies/Hibernate/SQL%2Bvs%2BHQL%2Bwith%2Bthe%2BSession%2BCache+hibernate+create+sql+query+caching&cd=1&hl=en&ct=clnk&client=safari

He seems to be saying that SQLQuery' will not use the cache. I know that Hibernate bypasses the cache for Stored Procedures. See if you can restate the queries in HQL and follow the caching doco here:

http://docs.jboss.org/hibernate/stable/core/reference/en/html/performance.html#performance-cache

Hi
the createSqlQuery statment is use just for get the keys for the test...
the real problem is

getSession().get(MinDBEmployee,key);

when we use it in a concurrent context
we get a lot af hibernate queries in the java output console.

attached ehcache.xml

thanks for you help

Hi
the createSqlQuery statment is use just for get the keys for the test...
the real problem is

getSession().get(MinDBEmployee,key);

when we use it in a concurrent context
we get a lot af hibernate queries in the java output console.

attached ehcache.xml

thanks for you help

Hi
the createSqlQuery statment is use just for get the keys for the test...
the real problem is

getSession().get(MinDBEmployee,key);

when we use it in a concurrent context
we get a lot af hibernate queries in the java output console.

attached ehcache.xml

thanks for you help

Ok

Well I cannot run your tests.

Can you please try with ehcache-1.5 and report the results? That will help to isolate it.

The issue seems to be resolved.Please let know in case of more information.