Apache Solr is an indexing and information retrieval server based on Lucene. We use is as a search engine for data stored in a PDR instance. It has to be deployed in a servlet container, like Apache Tomcat's Catalina. This article describes how to deploy Solr with Tomcat, connected to an Apache Web Server.

• Installation of Apache Tomcat

To provide a search engine for prosopographic data stored in our PDR, we use the indexing and retrieval capabilities of Apache's projects Lucene and Solr.

Solr is available at lucene.apache.org. Download a binary distribution (We are running Solr in version 3.6.0) and unpack it. You should find a subdirectory named example in its contents. From this subdirectory, extract solr and place it somehere convenient, e.g. under the root path of your Tomcat instance: /home/tomcat8082/tomcat1/solr/. This will be your Solr-home directory. By copying it from the dictriobutions example folder, we can start off with already sufficient default configurations.

The archive also contains a deployable web archive like dist/solr-X.X.X.war, which we can just drop into Tomcat's webapp folder. Now you are alomost done.

Some changes need to be made to some of Solr's configuration files.

tomcat1/conf/Catalina/localhost/solr.xml: need to set solr/home variable.

<?xml version="1.0" encoding="utf-8"?>
 <Context docBase="/home/tomcat8082/tomcat1/solr/solr.war" debug="0" crossContext="true">
  <Environment name="solr/home" type="java.lang.String" value="/home/tomcat8082/tomcat1/solr" override="true"/>
 </Context>

In tomcat1/solr/conf/solrconfig.xml, set dataDir:

<dataDir>${solr.data.dir:/home/tomcat8082/tomcat1/solr}</dataDir>

make sure there is an index folder inside solr's dataDir that Tomcat has sufficient permissions for. You'll possibly need to activate admin handlers in solrconfig.xml. retrieve ''schema.xml'' from the download page and save it to Solr's conf folder.