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RDF4J SPARQL endpoint installation

Guohui Xiao edited this page May 21, 2019 · 5 revisions

valid for Ontop Version 3.0.0-beta-2

Table of Contents

Using Ontop as a SPARQL endpoint requires the RDF4J framemork and some extra setup to install Ontop. There are three ways to do this which we now list. Please try the first options first, these are the easiest ones.

Using the ready to run Jetty package

This is by far the easiest way to run a Ontop SPARQL endpoint. You will simply need to run the pre-configured Jetty webserver.

  • Download the ZIP file "ontop-x.xx.x/ontop-jetty-bundle-*" from our Download page
  • Unzip the package into some folder, for example: /usr/jetty
  • Setup the variable JETTY_HOME to point to this folder. In Unix/Mac this can be done using the export command, e.g:
export JETTY_HOME=/usr/jetty/
  • Copy the corresponding JDBC driver (e.g. h2-1.4.196.jar) into `$JETTY_HOME/lib/ext`.
  • Go to directory ontop-base, and run the server with the command:
java -jar ../start.jar

If you need to change the default port, or if you want to increase the memory available for the server (recommended for best performance) you should modify the etc/jetty.xml and start.ini files respectively. For more information about Jetty and how to configure/run the web server, follow this link.

TIP: Increase your web-server's memory to get the best performance.
TIP: Keep in mind that the Jetty webserver and the RDF4J workbench are systems that are independent from Ontop, and hence we do not provide documentation on them. If you have any issues running the webserver/workbench please also check Jetty and RDF4J's documentation.

Troubleshooting

If you get the error of the form:

No suitable driver found for jdbc:postgresql://....
You need to copy the corresponding JDBC driver into $JETTY_HOME/lib/ext.

Installing Ontop using the prepacked RDF4J Workbench

These are instructions to set up a Ontop SPARQL endpoint on an existing Web Server such as Apache Tomcat. This is the second easiest option to install Ontop. We pre-packed Ontop into the RDF4J .war files, and you only need to drop this wars into the webapps folder of your web server, as follows:

  • Download the latest version of ontop-webapps: ontop-x.xx.x/ontop-webapps-x.xx.x.zip from our Download page.
  • Extract rdf4j-workbench.war and rdf4j-server.war from ontop-webapps-x.xx.x.zip
  • Move the two files to your server's [Server_Home]/webapps folder. You could also use the Tomcat Manager (http://localhost:8080/manager) to deploy the WAR files.
  • (Re)start the server.
  • Browse to http://localhost:8080/rdf4j-workbench.

If everything went right, you should see the main page with the list of repositories. More importantly, if you try to create a new repository, the drop-down menu will include "Ontop Virtual RDF Store".

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