The document discusses Stratio Search, an in-memory search engine that provides full text search capabilities for Cassandra databases with 200 million documents. It needs to index the documents quickly without having long batch processing times. Some solutions in the market integrate Lucene with Cassandra like Solandra but Stratio was developed to specifically address this problem and challenge of fast, distributed, and fault tolerant search for large Cassandra databases. Benchmark results show Stratio provides much faster response times for search compared to using Lucene directly.