[hibernate-dev] Hibernate Search: configure the LockingFactory

Hi all, to solve HSEARCH-284 (Lucene locks left around in application restart/crash) I am investigating the differences in all Lucene's LockFactory implementations; some of them are interesting and I would like to add a configuration option to replace the default one in Hibernate Search. 1) property name: I'm naming the property key "locking_strategy", scoped for each DirectoryProvider. 2) values: At first I was planning to use the usual design to be able to specify any implementation by specifying the qualified class name, but actually only 4 implementations make sense and if someone really needed the flexibility to implement their own they can define their own DirectoryProvider and use whatever they want. Also 2 of the base Lucene implementations are missing a public no-args constructor, so I would use only simple names: simple -> org.apache.lucene.store.SimpleFSLockFactory native -> org.apache.lucene.store.NativeFSLockFactory single -> org.apache.lucene.store.SingleInstanceLockFactory none -> org.apache.lucene.store.NoLockFactory 3) support for "none": I don't think we should let the user select something which is not compatible with H.Searche's design, so I am still trying to figure out if the NoLockFactory could be an option in case Search is the only process accessing the index. Currently inside search the IndexReaders/Searchers are read-only, and at most one IndexWriter is using the DP, so the locking strategy could be set to "none" IMHO. opinions? 4) default: The current default is "simple", which has the problem as reported in HSEARCH-284, so I was puzzled by the idea to define the "native" as the default one to have Search beginners avoid the locking problem, but I am hitting some problems under load testing, so I think the default should stay to "simple" at least for now. Sanne