Lucene Meetup Oakland

Lucene Meetup Oakland #

Though pretty late in the evening the room is packed with some 100 people. Most of them solr or pure lucene java users. There are quite a few Lucene committers at the meetup from all over the world. Several even have heard about Mahout - some even used it :)

Some introductiory questions to index sizes and query volumn: 1 Mio documents seem pretty standard for Lucene deployments - several people run 10 Mio neither. Some people even use indexes with up to billions of documents in Lucene - but at low query volumn. Usually people run projects with about 10 queries per second, but up to 500.

Eric’s presentation gives a nice introduction to what is going on with Lucene/Solr in terms of user interfaces. He starts with an overview of the problems that libraries face when building search engines - especially the facetting side of life. Especially interesting seem Solaritas - a velocity response writer that makes it easy to render search responses not in xml but in simple templated output. He of course also included an overview of the features of LucidFind, the Lucid hosted search engine for all Lucene projects and sub-projects. Take Home message: The interface is the application, as are the urls. Facets are not just for lists.

Second talk is given by Uwe giving an overview of the implementation of numeric searches and range queries and numeric range filters in Lucene.

Third presenter is Stefan on katta - a project on top of Lucene that adds index splits, load balancing, index replication, failover, distributed TFIDF. The mission of katta is to build a distributed Lucene for large indexes under high query load. The project heavily relies on zookeeper for coordination. It uses Hadoop IPC for search communication.

Lighting talks include talks by


  • Zoie: A realtime search extension for Lucene, developed inside of LinkedIn and now open sourced at google code.
  • Jukka proposed a new project: A Lucene-based content mangement system.
  • Next presenter highlighted the problem of document-to-document search. The problem here is that queries are not just one or two terms but more like 40 terms.
  • Next talk shared some statistics: more than 2s at average leads to 40% abandonance rate for sites. The presenter is very interested in the Lucene Ajax project. Before using solr the speaker set up projects with solutions like Endeca or Mercato. Solr to him is an alternative that supports facetting.
  • Andzrej gives an overview of index pruning in 5min - giving details on which approaches are currently being discussed in research as well as in the Lucene jira for index pruning.
  • Next talk was on Lucy - a lucene port to C.
  • Last talk gave an overview of the findings on analysing the Lucene community.
  • One other lightning talk by a guy using and deploying Typo3 pages. Typo3 does come with an integrated search engine. The presenter’s group built an extension to Typo3 that integrates the CMS with Solr search.
  • The final last talk is done by Grant Ingersoll on Mahout. Thanks for that!


Big Thanks to Lucid for sponsoring the meetup.