[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

[henk de boer (JIRA)]

    [ https://issues.jboss.org/browse/AS7-4552?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12686271#comment-12686271 ] 

henk de boer commented on AS7-4552:
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>From what I've seen in this discussion and my (poor) understanding of the code in question, the -ds.xml mechanism can't just be changed to use a javax.sql.DataSource, as it expects to do its own connection management, pooling, etc.

I would have to inspect the code, but I wonder it that's the case. If I'm not mistaken (and my JDBC knowledge is admittedly a bit rusty), a plain {{javax.sql.DataSource}} that's provided by the DB vendor is a direct alternative for {{java.sql.Driver}}. In fact, it's the more modern and preferable version. Such DataSource shouldn't do much if any connection management and certainly shouldn't do any pooling.

This DataSource typically calls the DriverManager ({{java.sql.DriverManager}}), which on its turn calls the {{Driver.connect}} method. {{java.sql.Driver#connect}} can take extra properties, but apart from "user" and "password" these are DB specific. The DataSource implementation can be configured with the same kind of DB specific properties.

So, _in my understanding_, the differences between {{java.sql.Driver}} and {{javax.sql.DataSource}} are rather small and they eventually end up at the same point.

Also, for XA, {{-ds.xml}} does require a {{javax.sql.XADataSource}}, not a {{java.sql.Driver}}. Other AS implementations, like GlassFish, do all their magic with a {{javax.sql.DataSource}} (or XA variant) instead of a Driver.
                
> 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.

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