Wildfly 8.2.0.Final: Misconfiguration because of example datasource or persistence.xml?

Question

I have three datasources configured in my persistence.xml:

<?xml version="1.0" encoding="UTF-8"?>
<persistence 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"
    version="2.1">

    <persistence-unit name="MyPersistenceUnit" transaction-type="JTA">
        <jta-data-source>java:jboss/datasources/myDS</jta-data-source>
        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
            <property name="hibernate.connection.useUnicode" value="true" />
            <property name="hibernate.connection.characterEncoding" value="UTF-8" />
            <property name="hibernate.connection.charSet" value="UTF-8" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.hbm2ddl.auto" value="validate" />
        </properties>
    </persistence-unit>

    <persistence-unit name="MyPersistenceTestUnit" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
            <property name="hibernate.connection.useUnicode" value="true" />
            <property name="hibernate.connection.characterEncoding" value="UTF-8" />
            <property name="hibernate.connection.charSet" value="UTF-8" />
            <property name="hibernate.connection.url" value="jdbc:postgresql://localhost:5432/mydb" />
            <property name="hibernate.connection.username" value="myuser" />
            <property name="hibernate.connection.password" value="mypass" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.hbm2ddl.auto" value="validate" />
        </properties>
    </persistence-unit>

    <persistence-unit name="MyLoggingUnit" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
            <property name="hibernate.connection.useUnicode" value="true" />
            <property name="hibernate.connection.characterEncoding" value="UTF-8" />
            <property name="hibernate.connection.charSet" value="UTF-8" />
            <property name="hibernate.connection.url" value="jdbc:postgresql://localhost:5432/mydb" />
            <property name="hibernate.connection.username" value="myuser" />
            <property name="hibernate.connection.password" value="mypass" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.hbm2ddl.auto" value="validate" />
        </properties>
    </persistence-unit>

</persistence>

The first is the 'default' unit. It's used by the standard entity manager. The second is needed for running JUnit tests outside of a Java EE environment. The third one is used for logging to be independent from JTA transactions.
This works. But when I start Wildfly, I even get some of these errors (although I don't use H2 in my application):

21:32:33,748 ERROR [org.hibernate.tool.hbm2ddl.SchemaValidator] (ServerService Thread Pool -- 51) HHH000319: Could not get database metadata: org.h2.jdbc.JdbcSQLException: Table "PG_CLASS" not found; SQL statement:
select relname from pg_class where relkind='S' [42102-173]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:331)

It only happens when the application is deployed.

The idea was to disable or remove the ExampleDS by admin console or in standalone.xml, but when I do that, I get a startup with errors:

21:36:20,992 ERROR [org.jboss.as.controller.management-operation] (Controller Boot Thread) JBAS014613: Operation ("deploy") failed - address: ([("deployment" => "com.zonacroft.mycuisine.webserver-TRUNK.war")]) - failure description: {"JBAS014771: Services with missing/unavailable dependencies" => [
    "jboss.persistenceunit.\"com.mydomain.myapp.webserver-TRUNK.war#MyLoggingUnit\".__FIRST_PHASE__ is missing [jboss.data-source.java:jboss/datasources/ExampleDS]",
    "jboss.persistenceunit.\"com.mydomain.myapp.webserver-TRUNK.war#MyPersistenceTestUnit\".__FIRST_PHASE__ is missing [jboss.data-source.java:jboss/datasources/ExampleDS]"

What on earth is going on here? Why does this persistence.xml need the exampleDS? Are the RESOURCE_LOCAL persistence units maybe wrong configured? (But if so, why do they work then). So what's the problem here?

[UPDATE]
I figured out that I don't get startup errors (with exampleDS enabled) when I remove the hibernate.hbm2ddl.auto properties from the RESOURCE_LOCAL persistence units. But it annoys me that I have to let the exampleDS of Wildfly enabled. Otherwise Wildfly would not start with the application as described above. Why is this so. What's wrong here?

Answer 1

You only define a datasource for the first persistence unit:

<jta-data-source>java:jboss/datasources/myDS</jta-data-source>

That means WildFly uses the default datasource exampleDS for your other persistence units.

This causes the exception, since the configured PostgreSQL dialect does not work for the default H2 datasource.