Class SSTableOfflineRelevel


  • public class SSTableOfflineRelevel
    extends java.lang.Object
    Create a decent leveling for the given keyspace/column family Approach is to sort the sstables by their last token given an original leveling like this (note that [ ] indicates token boundaries, not sstable size on disk, all sstables are the same size) L3 [][][][][][][][][][][] L2 [ ][ ][ ][ ] L1 [ ][ ] L0 [ ] Will look like this after being dropped to L0 and sorted by last token (and, to illustrate overlap, the overlapping ones are put on a new line): [][][] [ ][][][] [ ] [ ] ... Then, we start iterating from the smallest last-token and adding all sstables that do not cause an overlap to a level, we will reconstruct the original leveling top-down. Whenever we add an sstable to the level, we remove it from the sorted list. Once we reach the end of the sorted list, we have a full level, and can start over with the level below. If we end up with more levels than expected, we put all levels exceeding the expected in L0, for example, original L0 files will most likely be put in a level of its own since they most often overlap many other sstables
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static void main​(java.lang.String[] args)  
      • Methods inherited from class java.lang.Object

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

      • SSTableOfflineRelevel

        public SSTableOfflineRelevel()
    • Method Detail

      • main

        public static void main​(java.lang.String[] args)
                         throws java.io.IOException
        Parameters:
        args - a list of sstables whose metadata we are changing
        Throws:
        java.io.IOException