Mark, I have the same question so I did a little research on this. Not a complete answer but here is what I've found:
- "threads" was aded with SOLR-1352 (https://issues.apache.org/jira/browse/SOLR-1352). - Also see http://www.lucidimagination.com/search/document/a9b26ade46466ee/queries_regarding_a_paralleldataimporthandler for background info. - Only available in 3.x and trunk. Committed on 1/12/2010 by Noble Paul (who surely can tell you more accurate info than I can). - Seems like when using, each thread will call "nextRow" on your root entity datasource in parallel. - Not sure this will help with child entities (ie. I had hoped I could get it to build child caches in parallel but I don't think this is the case). - A doc comment on ThreadedEntityProcessorWrapper indicates this will help speed up running transformers becauses they'd be in parallel. This would make sense if maybe your database can only pull back so fast, but then you have an intensive transformer. Maybe adding a thread would make your processing no slower than the db... James Dyer E-Commerce Systems Ingram Content Group (615) 213-4311 -----Original Message----- From: markwaddle [mailto:m...@markwaddle.com] Sent: Tuesday, October 26, 2010 2:25 PM To: solr-user@lucene.apache.org Subject: How does DIH multithreading work? I understand that the thread count is specified on root entities only. Does it spawn multiple threads per root entity? Or multiple threads per descendant entity? Can someone give an example of how you would make a database query in an entity with 4 threads that would select 1 row per thread? Thanks, Mark -- View this message in context: http://lucene.472066.n3.nabble.com/How-does-DIH-multithreading-work-tp1776111p1776111.html Sent from the Solr - User mailing list archive at Nabble.com.
