[jboss-jira] [JBoss JIRA] (AS7-4552) JBoss AS 7 produces non-transactional (autocommit) EntityManager within transactional EJB methods when using 3rd party javax.sql.DataSource via @DataSourceDefinition

[jaikiran pai (JIRA)]

    [ https://issues.jboss.org/browse/AS7-4552?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12685531#comment-12685531 ] 

jaikiran pai commented on AS7-4552:
-----------------------------------

Reading through some specs and other documentation, I _think_ this might be more of a persistence provider implementation (Hibernate in this case) thing. One part of the spec (EJB 3.1 section 13.3.4) states that:

{quote}
13.3.4Enterprise Beans Using Container-Managed Transaction Demarcation
...
The enterprise bean methods must not use the following methods of the java.sql.Connection interface: commit, setAutoCommit ...
{quote}
which is a sign that (obviously) the enclosing transaction demarcation should be allowed to handle the commit. 
Now, I don't see anything in the spec which talks about how a JPA implementation (ex: Hibernate) should deal with connections which _already_ have autocommit set to true, in the context of a CMT bean. Looking at the Hibernate code, I see that in case of non-JTA access, Hibernate sets the autoCommit on the connection to false https://github.com/hibernate/hibernate-orm/blob/master/hibernate-core/src/main/java/org/hibernate/engine/transaction/internal/jdbc/JdbcIsolationDelegate.java#L70 but in case of JTA access, I don't see it checking the autocommit status on the connection https://github.com/hibernate/hibernate-orm/blob/master/hibernate-core/src/main/java/org/hibernate/engine/transaction/internal/jta/JtaIsolationDelegate.java#L91. I am not sure what the behaviour here should be - perhaps check the autocommit status and throw an error?

                
> JBoss AS 7 produces non-transactional (autocommit) EntityManager within transactional EJB methods when using 3rd party javax.sql.DataSource via @DataSourceDefinition
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: AS7-4552
>                 URL: https://issues.jboss.org/browse/AS7-4552
>             Project: Application Server 7
>          Issue Type: Bug
>          Components: EJB, JPA / Hibernate, Transactions
>    Affects Versions: 7.1.1.Final
>         Environment: java version "1.7.0_01"
> Java(TM) SE Runtime Environment (build 1.7.0_01-b08)
> Java HotSpot(TM) 64-Bit Server VM (build 21.1-b02, mixed mode)
> Linux ayaki.localdomain 3.3.0-4.fc16.x86_64 #1 SMP Tue Mar 20 18:05:40 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
>            Reporter: Craig Ringer
>            Assignee: Scott Marlow
>              Labels: autocommit, ejb, h2, h2sql, jdbc, jta, postgresql, transaction, transaction_manager, xa
>         Attachments: h2-test-logs.zip, JBossAS7ContainerTransactionsWith3rdPtyDataSource.zip, JBossAS7ContainerTransactionsWith3rdPtyDataSourceFixed.zip, JBossAS7ContainerTransactionsWithJBossDataSource.zip, JBossAS7H2Tests.zip
>
>
> When using a javax.sql.DataSource via @DataSourceDefinition to create the JTA datasource for a persistence unit, transactional EJB business methods run without transactions. No warning or error is emitted.
> Business method calls annotated @TransactionAttribute(TransactionAttributeType.REQUIRED) receive an EntityManager that *is in autocommit mode*, ie is *not* in a transaction.
> This violates the EJB3 spec and is a nasty problem.
> I discovered this when testing some code against PostgreSQL that uses deferred constraints to create two interdependent database objects; record A must have at least one record B referencing it, but record B also has a foreign key reference to record A. This can be satisfied only with deferred constraints, and works fine in SQL-level testing. When testing with Arquillian at the JBoss AS 7 / Hibernate / JPA level, though, it was breaking.
> Further investigation showed that the entity manager was in autocommit despite the method being transactional, as demonstrated by a test that tries to create and fetch from a cursor.
> I've now verified that the issue exists when using PostgreSQL or H2 as the database, so it's not specific to PostgreSQL. I've attached test cases for both databases.
> JBoss AS 7 clearly has some validation and checking to do because it *must* not allow an autocommit entity manager to be injected for transactional business methods. That's a really critical error, as it effectively means that transaction isolation is always at DIRTY_READ (which most DBs don't even support) rather than the requested level, and it's impossible to roll back work!
> As a workaround, it should be possible to deploy an archive with an embedded jboss-ds.xml instead of using @DataSourceDefinition . I haven't tested this - struggling to find documentation on in-archive deployment of jboss-ds.xml or equivalent jboss-specific descriptor like a datasource definition for jboss-web.xml .
> Using the jboss admin cli, or deploying a jboss datasource definition xml file to the deployments folder separately to the program archive, isn't subject to the problem. That's a PITA when unit testing, though.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.jboss.org/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira