The relationship between VIVO and Solr

What is Solr?

• A self-contained search application
  
  • maintains its own index
  • exists as a web application
  • send it requests to
    
    • search
    • add, update, or delete records
• May live in the same Tomcat as VIVO, or may not
  
  • Example Solr runs in Jetty
• Built on Lucene
• Open source

How does VIVO use Solr?

• The obvious is the search page
• Used internally when a search through the RDF would be too slow

How is the index kept up to date?

• When an individual is added/edited/deleted, Solr is given the new information and updates the index.
• Sometimes the index must be rebuilt
  
  • Most commonly, after an ingest, since some of the ingest mechanisms bypass the usual VIVO framework
    
    • It would be too slow to update the Solr index on each new statement from the ingest
    • Working to add a search-aware ingest method, which Harvester or other tools could use.
  • There is currently no way to rebuild only a section of the index.
    
    • Either it is up to date, or it must be fully rebuilt.
    • Plans are discussed to rebuilt named graphs, or a list of URIs.

  •  

    A rebuild is done on the side, then replaces the previous index, and Solr switches to the rebuilt one.

How is Solr created and configured?

• The Solr home directory
  
  • What is in it?
  • How does Solr find it?
• How is it built?
  
  • build script - Tomcat or otherwise.

How does VIVO contact Solr?

• Need to tell VIVO how to contact Solr
  
  • Authorization tests, now obsolete
• VIVO may start before Solr does. Usually does.

Signs of a possible Solr-related problem

• Smoke tests
  
  • Immediate failures
  • Separate thread, since Solr may start after VIVO
    
    • Go to the status page. Do you see a successful completion?
      
      • If not, wait (how long)?
• No content
  
  • Confirm that this is a Solr problem by navigating through VIVO and finding content.
• Others?

Is Solr working properly?

• Check the admin console.
• See the fields
• See the contents?
• Look in the Solr log

Does it help to rebuild?

• Really clean
  • Solr home directory
  • Tomcat/webapps, Tomcat/work, Tomcat/conf
  • ant clean deploy (or ant all)

Is the communication working?

• Check the VIVO log?
• Check the deploy.properties (both in the log and in the file)