Databus-derive-maven-plugin

Extension to the databus-maven-plugin, used to download and derive new datasets already released on the databus. mvn databus-derive:clone downloads all data into the build directory target/databus/derive/downloads, mvn clean deletes the downloaded data again. Later the plugin will feature better data housekeeping option, such as persisting some downloads in ${user.home}/.m2/databus and caching often used conversions.

working beta

• we are using it to derive the monthly DBpedia releases from the MARVIN pre-releases (parse and remove syntax errors)
• Code overlaps with the Databus Client. Merging and refactoring is required.

Current caveats:

• putting a version that does not exist into <version> will result in a java.util.NoSuchElementException: QueryIterPlainWrapper
• using is much less flexible than just giving the SPARQL query
• can only parse RDF-NTriples as .bz2 other data is simply copied
• Per default parsing data and cloning (e.g. create new versions for the databus-maven-plugin) are deactivated. You can turn them on with -DskipParsing=false -DskipCloning=false, but beware the plugin needs three times the space of the data (easier to debug).

Setup

Add the snapshot plugin repository, not required if you already use the databus-maven-plugin

    <pluginRepositories>
        <pluginRepository>
            <id>archiva.internal</id>
            <name>Internal Release Repository</name>
            <url>http://databus.dbpedia.org:8081/repository/internal</url>
        </pluginRepository>
        <pluginRepository>
            <id>archiva.snapshots</id>
            <name>Internal Snapshot Repository</name>
            <url>http://databus.dbpedia.org:8081/repository/snapshots</url>
            <snapshots>
                <updatePolicy>always</updatePolicy>
            </snapshots>
        </pluginRepository>
    </pluginRepositories>

Add the following plugin entry to the BaseBuild(<build>) element in your maven pom.

  <build>
  ...
    <plugins>
      <plugin>
        <groupId>org.dbpedia.databus</groupId>
        <artifactId>databus-derive-maven-plugin</artifactId>
        <version>1.0-SNAPSHOT</version>
        <executions>
          <execution>
            <goals>
              <goal>clone</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <versions>
            <version>https://databus.dbpedia.org/dbpedia/enrichment/mappingbased-literals/2019.03.01</version>
          </versions>
          <skipParsing>true</skipParsing>
          <skipCloning>true</skipCloning>
        </configuration>
      </plugin>
    </plugins>
  </build>

Note that you can also use a variable for configuration. This configuration downloads the whole DBpedia/mappings group.

 <properties>
	<!-- used for derive plugin, can be anything really -->
        <databus.deriveversion>2019.08.01</databus.deriveversion>
 </properties>

 <configuration>
          <versions>
            <version>https://databus.dbpedia.org/marvin/mappings/geo-coordinates-mappingbased/${databus.deriveversion}</version>
            <version>https://databus.dbpedia.org/marvin/mappings/instance-types/${databus.deriveversion}</version>
            <version>https://databus.dbpedia.org/marvin/mappings/mappingbased-literals/${databus.deriveversion}</version>
            <version>https://databus.dbpedia.org/marvin/mappings/mappingbased-objects/${databus.deriveversion}</version>
            <version>https://databus.dbpedia.org/marvin/mappings/mappingbased-objects-uncleaned/${databus.deriveversion}</version>
            <version>https://databus.dbpedia.org/marvin/mappings/specific-mappingbased-properties/${databus.marvinversion}</version>
          </versions>
          <skipParsing>true</skipParsing>
          <skipCloning>true</skipCloning>
 </configuration>

Maven manual install

git clone https://github.com/dbpedia/databus-derive.git
cd databus-derive
mvn clean install

Usage

Execute the plugin.

# normal
export MAVEN_OPTS="-Xmx24000m" 
# for 64Cores ~ 64GB to parse 5GB bz2
export MAVEN_OPTS="-Xmx64000m" 

mvn databus-derive:clone

Standalone Execution

It is also possible to just create cleaned triples and pareslogs.

mvn scala:run -Dlauncher=flatRdfParser -DaddArgs="$flat-rdf-in|-o|$flat-rdf-out|-r|$report-out"

or

./flatRdfParser <flat-rdf-in> <flat-rdf-out> <report-out>

for help add --help

Example

git clone https://github.com/dbpedia/databus-derive.git
cd databus-derive/ && mvn clean install
wget http://dbpedia-mappings.tib.eu/release/mappings/mappingbased-literals/2019.10.01/mappingbased-literals_lang\=de.ttl.bz2
./flatRdfParser mappingbased-literals_lang=de.ttl.bz2 --discard-warnings > mappingbased-literals_lang=de_cleaned.ttl