: I'm interested in improving my existing custom cache warming by being : selective about what updates rather than rebuilding completely. : : How can I tell what documents were updated/added/deleted from the old : cache to the new IndexSearcher?
cache warming in Solr is based mainly arround the idea of "what keys were in the old cache?" then "what's changed?" ... because regardless of what updates may have happened, wholesale docids shifts might have taken place. Of course, if you are dealing with a custom cache where the values aren't DocSetws or DocLists but your own custom objects that don't know about indiviual docIds, this doesn't really affect you as much. I'm not entirely sure i understand your situation, but one trick yonik found that really improved the cache warming in a custom CacheRegenerator i had was in dealing with big metadata documents that i was parsing into objects for use in a custom request handler. He pointed out that if i put the Lucene Document in my CacheValue objects, then when warming my newCache, i could do a search on the newSearcher, get the Document back, and if it was the same as the Document in the value from my oldCache i could copy it wholesale instead of redoing all of the parsing (this was complicated by Document not supporting equals, but you get the idea) I suppose to try and make CacheRegenerator's lives easier, we could expose the SolrIndexSearcher use with the oldCache -- but i'm still not sure how usefull that would be ... "diffing" two IndexSearchers isn't very easy, but i suppose in some cases comparing hte TermEnums for some fields (like the uniqueKey field for example) might be helpful. -Hoss
