Technical

The chapter outlines the processes for storing data from ATLAS and retrieving search results in ATLAS from the Nebula5 sub-system.

Storing ATLAS content in Nebula5

ATLAS prepares a document (in RDF format) containing the information that is provided by the user (content manager), as well as the automatically acquired one - additional metadata, concepts, keywords, named entities, summary. All of the RFD document attributes are firstly translated with the ATLAS MT engine. ATLAS sends the full RDF document in an "input" queue where Nebula5 processor fetched the message and stores it in a Lucene index.

Quering and retrieving search results

ATLAS transforms the user query into a key/value pairs array and sends this query to a synchronous message channel. The Nebula5 system transforms the key/value pairs into Lucene query and then to RDF query. The result sent to ALAS is an XML containing content item identifiers, matching the query, as well as a visualization context (highlighted text, original document metadata, etc...).