Deploying RacerManager

Following software must be properly installed and running on your computer, before you install and run RacerManager:

• A servlet container such as Tomcat (Version 5.0 or newer).
• RACER DL Reasoner (Version 1.9 or newer).

RacerManager is provided as an web application that can be deployed into a servlet container such as Tomcat. If you have Tomcat running on your computer, the installation is quite simple: you can deploy the downloaded war file using the Deployer or the Manager Web Application of Tomcat. Alternatively you may just copy the war file into the webapps directory of your Tomcat installation and restart Tomcat. For details on Tomcat please refer to Apache Tomcat Homepage.

License and download information about the DL Reasoner RACER can be found here.

RacerManager version 2.0 has been tested with Tomcat 5.0, RacerPro 1-9-0 on Windows XP Professional and Suse Linux.

Configuring RacerManager

The RacerManager configuration file racerManager.xml can be found in the WEB-INF/conf directory of the RacerManager installation. (i.e /TOMCAT_HOME/webapps/RacerManager-0.2/WEB-INF/conf)

The default file racerManager.xml below configures two RacerPro instances to run on the local machine on ports 9081 and 9082 and each of them to load the university benchmark after startup:

<?xml version="1.0" encoding="ISO-8859-1" ?>
<configuration>
<racerServerExecutable>C:\RacerPro-1-9-0\lw\RacerPro.exe</racerServerExecutable>
<serverdirectives>
 <directive>(set-nrql-mode 1)</directive>
 <directive>(enable-optimized-query-processing)</directive>
 <directive>(set-unique-name-assumption t)</directive>
</serverdirectives>
<cacheExpires>true</cacheExpires>
<expireAfter>10</expireAfter>
<racerservers>
 <racerserver>
   <host>localhost</host>
   <protocol>tcp</protocol>
   <port>9081</port>
   <defaultKBs>
        <defaultKB>
          <type>owl</type>
          <namespace>http://www.lehigh.edu/%7Ezhp2/2004/0401/univ-bench.owl#</namespace>
          <uri>http://www.sts.tu-harburg.de/~at.kaya/ont/university0.owl</uri>
        </defaultKB>
   </defaultKBs>
 </racerserver>
 <racerserver>
   <host>localhost</host>
   <protocol>tcp</protocol>
   <port>9082</port>
   <defaultKBs>
    <defaultKB>
          <type>owl</type>
          <namespace>http://www.lehigh.edu/%7Ezhp2/2004/0401/univ-bench.owl#</namespace>
          <uri>http://www.sts.tu-harburg.de/~at.kaya/ont/university0.owl</uri>
    </defaultKB>
   </defaultKBs>
 </racerserver>
</racerservers>
</configuration>

• The racerServerExecutable tag defines the path to RacerPro on the local machine. RacerManager uses this information to start RacerPro instance(s).
• Each directive tag inside the serverdirectives tag is a RacerPro directive used to configure the Reasoner. The order of the directives may be important when configuring RacerPro. The directives in the default configuration file configure RacerPro to achive better performance with the Lehigh University Benchmark (LUBM). For further information on available directives and their effects refer to RacerPro Reference Manual.
• The cacheExpires tag determines the caching behaviour of the system. If it is turned on (set to true) the next tag namely expireAfter determines the time limit after which the cache will expire (in minutes). If the cache is turned off by setting the cacheExpires tags value to false the value set in expireAfter is ignored.
• The racerservers tag defines the list of RacerPro instances RacerManager will manage. In the file above two RacerPro instances are defined to be managed by RacerManager (using the racerserver tag). In the host tag the host name, on which the RacerPro instance will run, is defined. For the protocol tag the only allowed value is tcp at the moment. This means that RacerManager will communicate with this RacerPro instance over tcp. The port on which this RacerPro instance will run is defined in the port tag. Using defaultKBs tag a list of KnowledgeBases can be defined that will be loaded by this RacerPro instance after startup. Each defaultKB tag specifies information about the type, namespace and uri of a KB with the type, namespace and uri tags. The only allowed value for the type of a KB is owl.

Notes:

• RacerManager will start up a RacerPro instance only if the host name is localhost. If RacerManager should manage RacerPro instance(s) running on remote machine(s) these instances must have been started before (i.e. RacerManager can not start programs on remote machines). In this case their IP addresses must be given in the corresponding host tags. RacerManager will contact these remote RacerPro instances like local RacerPro instances during startup and instruct them to load the default KBs listed.
• Due to the nature of the OWL-QL standard a client may require answers to his query from any KB in the Web. Each time a query arrives RacerManager it looks for a RacerPro instance that already loaded the KB to answer it. Only if it can not find an idle RacerPro instance, it will instruct an idle RacerPro instance to load the KB. Reading large KBs from the Web may take a long time. Using the defaultKB tag some frequently used, large KBs can be loaded during startup.

Deploying OwlQlWebApp

You can download another web application called OwlQlWebApp from the download page. OwlQlWebApp is demo client application that uses RacerManager to query OWL ontologies. It calls the web service provided by the RacerManager web application. You can deploy OwlQlWebApp in the same way like RacerManager.

To learn more about the OwlQlWebApp follow the menu item OwlQlWebApp in the left navigation bar.