Managing caching 

Modifying the solrconfig.xml file to use the StandardDirectoryFactory.

The DSENRTCachingDirectoryFactory is deprecated. If you use DSENRTCachingDirectoryFactory or the NRTCachingDirectoryFactory, modify the solrconfig.xml to use the StandardDirectoryFactory. For example, change the directoryFactory element in the solrconfig.xml file as follows: <directoryFactory class="solr.StandardDirectoryFactory" name="DirectoryFactory"/>..

The default solr.StandardDirectoryFactory is files system based, and tries to pick the best implementation for the current JVM and platform. You can force a particular implementation by specifying solr.MMapDirectoryFactory, solr.NIOFSDirectoryFactory, or solr.SimpleFSDirectoryFactory.