private boolean removeOverRedundancy() {
    Move bestMove = null;
    BucketRollup first = null;
    while (bestMove == null) {
      if (model.getOverRedundancyBuckets().isEmpty()) {
        return false;
      }

      first = model.getOverRedundancyBuckets().first();
      bestMove = model.findBestRemove(first);
      if (bestMove == null) {
        if (logger.isDebugEnabled()) {
          logger.debug(
              "Skipping overredundancy bucket {} because couldn't find a member to remove from?",
              first);
        }
        model.ignoreOverRedundancyBucket(first);
      }
    }
    Member targetMember = bestMove.getTarget();

    model.remoteOverRedundancyBucket(first, targetMember);

    return true;
  }
Remove copies of buckets that have more than the expected number of redundant copies.
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/rebalance/RemoveOverRedundancy.java