code: public static void removeUnreadableSSTables(File directory)
      {
          for (Keyspace keyspace : Keyspace.all())
          {
              for (ColumnFamilyStore baseCfs : keyspace.getColumnFamilyStores())
              {
                  for (ColumnFamilyStore cfs : baseCfs.concatWithIndexes())
                      cfs.maybeRemoveUnreadableSSTables(directory);
              }
          }
      }
docs: Removes every SSTable in the directory from the appropriate DataTracker's view.
  @param directory the unreadable directory, possibly with SSTables in it, but not necessarily.