How to import Neo4J Data into Apache Solr

The Apache Solr platform is a popular, blazing-fast, open source enterprise search solution built on Apache Lucene.

Apache Solr is equipped with the Data Import Handler (DIH), which can import data from databases and, XML, CSV, and JSON files. When paired with the CData JDBC Driver for Neo4J, you can easily import Neo4J data to Apache Solr. In this article, we show step-by-step how to use CData JDBC Driver in Apache Solr Data Import Handler and import Neo4J data for use in enterprise search.

Create an Apache Solr Core and a Schema for Importing Neo4J

1. Run Apache Solr and create a Core.

   > solr create -c CDataCore

   For this article, Solr is running as a standalone instance in the local environment and you can access the core at this URL: http://localhost:8983/solr/#/CDataCore/core-overview
2. Create a schema consisting of "field" objects to represent the columns of the Neo4J data to be imported and a unique key for the entity. LastModifiedDate, if it exists in Neo4J, is used for incremental updates. If it does not exist, you cannot do the deltaquery in the later section. Save the schema in the managed-schema file created by Apache Solr.

	Neo4jUniqueKey
	
	
	
	
	
	
	
	 
	

👁 Define schema in Solr for Neo4J data.

3. Install the CData Neo4J JDBC Driver. Copy the JAR and license file (cdata.neo4j.jar and cdata.jdbc.neo4j.lic) to the Solr directory.
   
   • CData JDBC JAR file: C:\Program Files\CData\CData JDBC Driver for Neo4J ####\lib
   • Apache Solr: solr-8.5.2\server\lib

Now we are ready to use Neo4J data in Solr.

Define an Import of Neo4J to Apache Solr

In this section, we walk through configuring the Data Import Handler.

1. Modify the Config file of the created Core. Add the JAR file reference and add the DIH RequestHander definition.

   	
   
   	<lib dir="${solr.install.dir:../../../..}/dist/" regex="solr-dataimporthandler-.*\.jar" />
   
   	<requestHandler name="/dataimport" class="org.apache.solr.handler.dataimport.DataImportHandler">
   		<lst name="defaults">
   			<str name="config">solr-data-config.xml</str>
   		</lst>
   	</requestHandler>

2. Next, create a solr-data-config.xml at the same level. In this article, we retrieve a table from Neo4J, but you can use a custom SQL query to request data as well. The Driver Class and a sample JDBC Connection string are in the sample code below.

   	
   	<dataConfig>
   		<dataSource driver="cdata.jdbc.neo4j.Neo4jDriver" url="jdbc:neo4j:Server=localhost;Port=7474;User=my_user;Password=my_password;">
   		</dataSource> 
   		<document> 
   			<entity name="ProductCategory" 
   				query="SELECT Id,Neo4jColumn1,Neo4jColumn2,Neo4jColumn3,Neo4jColumn4,Neo4jColumn5,Neo4jColumn6,Neo4jColumn7,LastModifiedDate FROM ProductCategory"
   				deltaQuery="SELECT Id FROM ProductCategory where LastModifiedDate >= '${dataimporter.last_index_time}'"
   				deltaImportQuery="SELECT Id,Neo4jColumn1,Neo4jColumn2,Neo4jColumn3,Neo4jColumn4,Neo4jColumn5,Neo4jColumn6,Neo4jColumn7,LastModifiedDate FROM ProductCategory where Id=${dataimporter.delta.Id}">
   				<field column="Id" name="Id" ></field>
   				<field column="Neo4jColumn1" name="Neo4jColumn1" ></field>
   				<field column="Neo4jColumn2" name="Neo4jColumn2" ></field>
   				<field column="Neo4jColumn3" name="Neo4jColumn3" ></field>
   				<field column="Neo4jColumn4" name="Neo4jColumn4" ></field>
   				<field column="Neo4jColumn5" name="Neo4jColumn5" ></field>
   				<field column="Neo4jColumn6" name="Neo4jColumn6" ></field>
   				<field column="Neo4jColumn7" name="Neo4jColumn7" ></field>
   				<field column="LastModifiedDate" name="LastModifiedDate" ></field> 
   			</entity>
   		</document>
   	</dataConfig>

3. In the query section, set the SQL query that select the data from Neo4J. deltaQuery and deltaImportquery define the ID and the conditions when using incremental updates from the second import of the same entity.
4. After all settings are done, restart Solr.

   	> solr stop -all
   	> solr start
   	

Run a DataImport of Neo4J Data.

1. Execute DataImport from the URL below:
   http://localhost:8983/solr/#/CDataCore/dataimport//dataimport 👁 Load Neo4J data to Solr using Data Import.
   
2. Select the "full-import" Command, choose the table from Entity, and click "Execute." 👁 Execute full import in Solr.
   
3. Check the result of the import from the Query. 👁 Check the full import result of Neo4J.
   
4. Try an incremental update using deltaQuery. Modify some data in the original Neo4J data set. Select the "delta-import" command this time from DataImport window and click "Execute." 👁 Execute Delta import in Solr.
   
5. Check the result of the incremental update. 👁 Check the delta import result of Neo4J.
   

Using the CData JDBC Driver for Neo4J you are able to create an automated import of Neo4J data into Apache Solr. Download a free, 30 day trial of any of the hundreds of CData JDBC Drivers and get started today.