On 7/6/2015 2:06 PM, Vincenzo D'Amore wrote: > just a simple question, if I change from > solr.NRTCachingDirectoryFactory to solr.MMapDirectoryFactory should I > reindex the entire collection? > > I have tried in a test environment and the change seems to be applied > seamless.
No, reindexing is not required. Only restarting Solr. MMapDirectoryFactory is not actually an upgrade from NRTCachingDirectoryFactory. The NRT factory is a wrapper. On 64-bit systems, it defaults to wrapping around MMapDirectoryFactory. This wrapper provides in-memory caching of new segments if they are small enough -- for Near Real Time indexing. For the rest of the index that's stored on disk, on most systems, it is identical to the MMap factory. http://lucene.apache.org/core/5_0_0/core/org/apache/lucene/store/NRTCachingDirectory.html Thanks, Shawn
