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

      first = model.getLowRedundancyBuckets().first();
      bestMove = model.findBestTarget(first, true);
      if (bestMove == null && !model.enforceUniqueZones()) {
        bestMove = model.findBestTarget(first, false);
      }
      if (bestMove == null) {
        if (logger.isDebugEnabled()) {
          logger.debug("Skipping low redundancy bucket {} because no member will accept it", first);
        }
        model.ignoreLowRedundancyBucket(first);
      }
    }

    model.createRedundantBucket(first, bestMove.getTarget());

    return true;
  }
Try to satisfy redundancy for a single bucket.

@return true if we actually created a bucket somewhere.
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/rebalance/SatisfyRedundancy.java