On Wed, Apr 17, 2013 at 7:02 AM, Thomas Matthijs <li...@selckin.be> wrote: > On Wed, Apr 17, 2013 at 12:57 PM, Ashish Sarna <ashish.sa...@thepsi.com>wrote: > >> I want to take back-up of a Lucene index. I need to ensure that index files >> would not change when I take their backup. >> > > >> >> I am concerned about the housekeeping/merge/optimization activities which >> Lucene performs internally. I am not sure when/how these activities are >> performed by Lucene and how we can prevent them. >> >> > > Use a > http://lucene.apache.org/core/4_2_1/core/org/apache/lucene/index/SnapshotDeletionPolicy.html > Take a snapshot, backup/copy all the files in the commit, relase the > snapshot
That's right! Because Lucen is "write-once" (each file is opened, written, and never changed, and no file is over-written), the SnapshotDeletionPolicy let's you take a hot (live) point-in-time backup even while IndexWriter continues making changes to the index. As long as you hold that snapshot, all files it references will not be deleted, just be sure to release it once you're done backing up. Mike McCandless http://blog.mikemccandless.com --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
