Omar,

Currently Teiid does not have translator for the JENA. If this were any JDBC driver that supports SQL, there are some ansi compatible built-in translators that you could use, however this is SPARQL based query language it mandates the requirement to develop a custom translator where relational constructs to the RDF model need to be derived. When we looked at this feasibility of RDF to relational model, we were not completely satisfied with "a" solution. The issue is captured here [TEIID-3126] Add OWL / RDF translators to TeiiD - JBoss Issue Tracker

If you want to help contribute such translator, please let us know, as we could use a subject matter expert in RDF.

Ramesh..

It is not standard extension of the JDBC Driver load, so it is custom service loader specific to JENA. Ask him who is responsible for loading it, and how does one load it? They should have bootstrapped using the standard JDBC4 Driver service loader mechanism to initialize it, then we would not have issues.

I was going to ask on email thread but having some MarkMail issues.

Omar,

Now I can not even get to MarkMail to read the response. Basically what they need to do, replace their ServiceLoader mechanism with standard JDBC4 ServiceLoader mechanism like

teiid/client/src/main/resources/META-INF/services at master · rareddy/teiid · GitHub

That will register their Driver class, and in their driver class possibly in a "static block" call ARQ.init() that will initialize every time one uses their JDBC driver. The issue is not with the JBoss modules, it is how JENA driver designed.

Ramesh..

Hi Ramesh,

Apache Jena JDBC does use java.sql.Driver. Omars stacktrace shows that Jena JDBC code has been loaded and executed.

at org.apache.jena.jdbc.statements.JenaStatement.execute(JenaStatement.java:273)   <----- Jena JDBC code

  at org.jboss.jca.adapters.jdbc.WrappedStatement.execute(WrappedStatement.java:182)

  at org.teiid.translator.jdbc.JDBCDirectQueryExecution.execute(JDBCDirectQueryExecution.java:83)

  ... 17 more

So the issue is not about finding the driver as far as I can see.

Jena uses ServiceLoader itself and the report is indicative of that part not being configured properly for org.apache.jena.system.JenaSubsystemLifecycle.

Jena has several service files for the same interface - if combing jena jars, then that process needs to combine service files for org.apache.jena.system.JenaSubsystemLifecycle (for example, the maven shade plugin ServicesResourceTransformer does this)

There was an issue with the bundled jena-jdbc-driver-bundle (now fixed) but Omar reports an issue when using the driver in unbundled form via

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

<module xmlns="urn:jboss:module:1.0" name="org.apache.jena">

  <resources>

  <resource-root path="jena-jdbc-core-3.1.0.jar"/>

  <resource-root path="jena-jdbc-driver-remote-3.1.0.jar"/>

  <resource-root path="jena-arq-3.1.0.jar"/>

  <resource-root path="jena-core-3.1.0.jar"/>

  <resource-root path="jena-base-3.1.0.jar"/>

  <resource-root path="jena-cmds-3.1.0.jar"/>

...

and the stacktrace suggests incomplete Jena initialization.

    Andy

I read through the messages on the link now.

The JBoss module system (module.xml) does NOT bundle the jars. It is another modular class loader. There is no code it can automatically run (it can but its own extensions), it does not understand the JenaLifeCycle service loader. Does calling

JenaSystem.init() ;

enough? if I were to write a plain JAVA application, how is this code being initialized?

Ramesh..

JenaSystem.init() is called by various entry points into the code including NodeValue class initialization.

So (1) it is being called (2) it is not fully initializing Jena.

Do explicit calls would force the sequence outside of services files:

  InitJenaCore.init();

  RIOT.init();

  ARQ.init();

before calling any Jena code or loading the JDBC driver.

Ah - "modular class loader"

Forgive my ignorance about the system but is there one classloader for all the jars in the module?

I checked - Jena's JDBC driver RemoteEndpointDriver does call jena system initialization in a class static initializer.

Andy,

Does JenaSystem.init() in turn execute

  InitJenaCore.init();

  RIOT.init();

  ARQ.init();

or both separate initialization stacks and both are needed?

>Forgive my ignorance about the system but is there one classloader for all the jars in the module?

Yes, it is single class loader per module.xml, if it has <dependencies> section those are separate modules that this one depends upon

>>I wonder if it's org.apache.xerces vs javax.xml? In that the way JBoss's module loader is invoking it.

JBoss also uses xercess, and I believe the parent class loader already have this module loaded thus you may be seeing this issue, I would say this may be core of the issue.

>>but... is not picking up META-INF/services/org.apache.jena.system.JenaSubsystemLifecycle

It will not, as this is JENA's own extension mechanism. But I see that this is being executed through Driver extension, but hitting above issue IMO.

Can you try replacing you module.xml like below (do not use bundle jar)

<module xmlns="urn:jboss:module:1.3" name="org.apache.jena">
    <properties>
        <property name="jboss.api" value="private"/>
    </properties>
     
    <resources>
        <resource-root path="collection-0.6.jar"/>
        <resource-root path="commons-csv-1.0.jar"/>
        <resource-root path="httpclient-4.2.6.jar"/>
      <resource-root path="httpclient-cache-4.2.6.jar"/>
        <resource-root path="httpcore-4.2.5.jar"/>
      <resource-root path="jena-arq-3.1.0.jar"/>
      <resource-root path="jena-base-3.1.0.jar"/>
      <resource-root path="jena-cmds-3.1.0.jar"/>
      <resource-root path="jena-core-3.1.0.jar"/>
      <resource-root path="jena-iri-3.1.0.jar"/>
      <resource-root path="jena-shaded-guava-3.1.0.jar"/>
      <resource-root path="jena-tdb-3.1.0.jar"/>
      <resource-root path="jsonld-java-0.7.0.jar"/>
    </resources>


    <dependencies>
        <module name="javax.api"/>
        <module name="org.slf4j"/>
        <module name="org.apache.log4j"/>
        <module name="org.apache.commons.cli"/> <!--1.2 needs 1.3-->
        <module name="org.apache.commons.codec"/> <!-- 1.10 needs 1.9 -->
        <module name="org.apache.commons.io"/>
        <module name="org.apache.commons.lang" slot="3.3.2"/>
        <module name="com.fasterxml.jackson.core.jackson-core"/>
        <module name="com.fasterxml.jackson.core.jackson-annotations"/>
        <module name="com.fasterxml.jackson.core.jackson-databind"/>
        <module name="org.apache.thrift" /> <!--9.1 needs 9.2 -->
        <module name="org.apache.log4j" />       
        <module name="org.slf4j" />
        <module name="org.slf4j.jcl-over-slf4j" />
        <module name="org.slf4j.ext"/>
        <module name="org.apache.xerces"/>
        <module name="javax.xml.bind.api"/>
        <module name="javax.xml.rpc.api"/>
        <module name="javax.xml.soap.api"/>
        <module name="javax.xml.stream.api"/>
        <module name="javax.xml.ws.api"/>
    </dependencies>
</module>