In JBoss/WildFly, when configuring a data source, there is a JTA option, which is disabled by default:
<datasource jta="false" jndi-name="java:/wt/testds" pool-name="testds" enabled="true" use-ccm="false">
...
</datasource>
Now I want to associate this data source with JPA using JTA transaction type:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="test" transaction-type="JTA">
<jta-data-source>java:/wt/testds</jta-data-source>
</persistence-unit>
</persistence>
Do I also need to enable JTA on the data source?
Yes, of course you need to enable JTA on a datasource if you want to have jta transactions!
Your XML/JBoss/Wildfly config file will look like this:
<datasource jta="true" ...
In our webapp persistence-unit, the datasource looks like this:
<jta-data-source>java:jboss/datasources/CoreDS</jta-data-source>
The transaction-type="JTA" isn't necessary, at least not in my setup (Wildfly 8.1).
In your Java code you can go like this to use transactions:
@TransactionManagement(TransactionManagementType.CONTAINER) // class level
public class ...
...
@PersistenceContext(unitName = "CoreJPA")
EntityManager em;
@Resource
private EJBContext ejbContext;
...
@TransactionAttribute(TransactionAttributeType.REQUIRES_NEW) // method level
public void doSomething(...)
And if you need to rollback, you do this:
try {
...
} catch (Throwable t) {
log.error("Exception in create work order: " + t.getMessage());
ejbContext.setRollbackOnly();
throw t;
}
There are a lot of resources about this that can be found using Google.
I've just experienced a problem related to this issue.
I was running a container managed transaction involving approximately 20,000 inserts into a MySQL database.
The transaction failed randomly, sometimes after around 3,500 inserts, other times after around 6,000 inserts, etc.
After investigation I found that the JTA option on the WildFly datasource definition was set to false.
Changing this setting to true fixed the problem, so I would agree with @user3472929 that JTA should be set to true in the datasource definition unless you have some specific reason not to.
I think you should use jta. And if you set jta to false in the container configuration file, jta will be disabled for JPA, so the transaction-type for JPA will be "RESOURCE_LOCAL", which has some nasty side effect. By the way, jta is true in the container configuration file by default.
