Class CombinedDeletionPolicy

  • public class CombinedDeletionPolicy
    extends org.apache.lucene.index.IndexDeletionPolicy
    An IndexDeletionPolicy that coordinates between Lucene's commits and the retention of translog generation files, making sure that all translog files that are needed to recover from the Lucene commit are not deleted.

    In particular, this policy will delete index commits whose max sequence number is at most the current global checkpoint except the index commit which has the highest max sequence number among those.

    • Method Summary

      Modifier and Type Method Description
      static java.lang.String commitDescription​(org.apache.lucene.index.IndexCommit commit)
      Returns a description for a given IndexCommit.
      static org.apache.lucene.index.IndexCommit findSafeCommitPoint​(java.util.List<org.apache.lucene.index.IndexCommit> commits, long globalCheckpoint)
      Find a safe commit point from a list of existing commits based on the supplied global checkpoint.
      protected int getDocCountOfCommit​(org.apache.lucene.index.IndexCommit indexCommit)  
      void onCommit​(java.util.List<? extends org.apache.lucene.index.IndexCommit> commits)  
      void onInit​(java.util.List<? extends org.apache.lucene.index.IndexCommit> commits)  
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Method Detail

      • onInit

        public void onInit​(java.util.List<? extends org.apache.lucene.index.IndexCommit> commits)
        Specified by:
        onInit in class org.apache.lucene.index.IndexDeletionPolicy
      • onCommit

        public void onCommit​(java.util.List<? extends org.apache.lucene.index.IndexCommit> commits)
        Specified by:
        onCommit in class org.apache.lucene.index.IndexDeletionPolicy
      • getDocCountOfCommit

        protected int getDocCountOfCommit​(org.apache.lucene.index.IndexCommit indexCommit)
      • findSafeCommitPoint

        public static org.apache.lucene.index.IndexCommit findSafeCommitPoint​(java.util.List<org.apache.lucene.index.IndexCommit> commits,
                                                                              long globalCheckpoint)
        Find a safe commit point from a list of existing commits based on the supplied global checkpoint. The max sequence number of a safe commit point should be at most the global checkpoint. If an index was created before 6.2 or recovered from remote, we might not have a safe commit. In this case, this method will return the oldest index commit.
        commits - a list of existing commit points
        globalCheckpoint - the persisted global checkpoint from the translog, see Translog.readGlobalCheckpoint(Path, String)
        a safe commit or the oldest commit if a safe commit is not found
      • commitDescription

        public static java.lang.String commitDescription​(org.apache.lucene.index.IndexCommit commit)
        Returns a description for a given IndexCommit. This should be only used for logging and debugging.