public void prepare(ColumnFamilyStore cfs) { if (tree.partitioner() instanceof RandomPartitioner) { // You can't beat an even tree distribution for md5 tree.init(); } else { List<DecoratedKey> keys = new ArrayList<DecoratedKey>(); for (DecoratedKey sample : cfs.keySamples(request.range)) { assert request.range.contains(sample.token) : "Token " + sample.token + " is not within range " + request.range; keys.add(sample); } if (keys.isEmpty()) { // use an even tree distribution tree.init(); } else { int numkeys = keys.size(); Random random = new Random(); // sample the column family using random keys from the index while (true) { DecoratedKey dk = keys.get(random.nextInt(numkeys)); if (!tree.split(dk.token)) break; } } } logger.debug("Prepared AEService tree of size " + tree.size() + " for " + request); ranges = tree.invalids(); }