/**
* Add a new Column <long,byte[]> to a given row in a given column family
*
* @param columnFamily column family name
* @param row row name
* @param key long key value
* @param value value as a byte array
* @param keyspace CassandraKeySpace
* @throws CassandraDataAccessException
*/
public static void addLongByteArrayColumnToRow(
String columnFamily, String row, long key, byte[] value, Keyspace keyspace)
throws CassandraDataAccessException {
if (keyspace == null) {
throw new CassandraDataAccessException("Can't add Data , no keySpace provided ");
}
if (columnFamily == null || row == null || value == null) {
throw new CassandraDataAccessException(
"Can't add data with columnFamily = "
+ columnFamily
+ " and row="
+ row
+ " key = "
+ key
+ " value = "
+ value);
}
try {
Mutator<String> messageContentMutator = HFactory.createMutator(keyspace, stringSerializer);
messageContentMutator.addInsertion(
row,
columnFamily,
HFactory.createColumn(key, value, longSerializer, bytesArraySerializer));
messageContentMutator.execute();
} catch (Exception e) {
throw new CassandraDataAccessException(
"Error while adding new Column <int,byte[]> to cassandra store", e);
}
}
// TM
@Override
protected void batchDeleteRow(String cf, List<Node[]> li, String keyspace) {
if (cf.equals(CF_C_SPO)) {
super.batchDeleteRow(cf, li, keyspace);
} else if (cf.equals(CF_PO_S)) {
Mutator<byte[]> m = HFactory.createMutator(getExistingKeyspace(keyspace), _bs);
for (Node[] nx : li) {
// reorder for the key
Node[] reordered = Util.reorder(nx, _maps.get(cf));
ByteBuffer rowKey = createKey(new Node[] {reordered[0], reordered[1]});
String colKey = reordered[2].toN3();
// delete the full row
m.addDeletion(rowKey.array(), cf);
}
m.execute();
} else {
Mutator<String> m = HFactory.createMutator(getExistingKeyspace(keyspace), _ss);
for (Node[] nx : li) {
// reorder for the key
Node[] reordered = Util.reorder(nx, _maps.get(cf));
String rowKey = reordered[0].toN3();
m.addDeletion(rowKey, cf);
_log.info("Delete full row for " + rowKey + " cf= " + cf);
}
m.execute();
}
}
/**
* Add Message to a Given Queue in Cassandra
*
* @param columnFamily ColumnFamily name
* @param queue queue name
* @param messageId Message id
* @param message message in bytes
* @param keyspace Cassandra KeySpace
* @throws CassandraDataAccessException In case of database access error
*/
public static void addMessageToQueue(
String columnFamily, String queue, long messageId, byte[] message, Keyspace keyspace)
throws CassandraDataAccessException {
if (keyspace == null) {
throw new CassandraDataAccessException("Can't add Data , no mutator provided ");
}
if (columnFamily == null || queue == null || message == null) {
throw new CassandraDataAccessException(
"Can't add data with columnFamily = "
+ columnFamily
+ " and queue="
+ queue
+ " message id = "
+ messageId
+ " message = "
+ message);
}
try {
Mutator<String> mutator = HFactory.createMutator(keyspace, stringSerializer);
mutator.addInsertion(
queue.trim(),
columnFamily,
HFactory.createColumn(messageId, message, longSerializer, bytesArraySerializer));
mutator.execute();
} catch (Exception e) {
throw new CassandraDataAccessException("Error while adding message to Queue", e);
}
}
/**
* Add a Mapping to a Given Row in cassandra column family. Mappings are used as search indexes
*
* @param columnFamily columnFamilyName
* @param row row name
* @param cKey key name for the adding column
* @param cValue value for the adding column
* @param keyspace Cassandra KeySpace
* @throws CassandraDataAccessException In case of database access error or data error
*/
public static void addMappingToRaw(
String columnFamily, String row, String cKey, String cValue, Keyspace keyspace)
throws CassandraDataAccessException {
if (keyspace == null) {
throw new CassandraDataAccessException("Can't add Data , no KeySpace provided ");
}
if (columnFamily == null || row == null || cKey == null) {
throw new CassandraDataAccessException(
"Can't add data with columnFamily = "
+ columnFamily
+ " and rowName="
+ row
+ " key = "
+ cKey);
}
try {
Mutator<String> mutator = HFactory.createMutator(keyspace, stringSerializer);
mutator.addInsertion(
row,
columnFamily,
HFactory.createColumn(cKey, cValue.trim(), stringSerializer, stringSerializer));
mutator.execute();
} catch (Exception e) {
throw new CassandraDataAccessException("Error while adding a Mapping to row ", e);
}
}
/**
* Add new Column<long,long> to a given row in a given cassandra column family
*
* @param columnFamily column family name
* @param row row name
* @param key long key value of the column
* @param value long value of the column
* @param keyspace Cassandra KeySpace
* @throws CassandraDataAccessException
*/
public static void addLongContentToRow(
String columnFamily, String row, long key, long value, Keyspace keyspace)
throws CassandraDataAccessException {
if (keyspace == null) {
throw new CassandraDataAccessException("Can't add Data , no keySpace provided ");
}
if (columnFamily == null || row == null) {
throw new CassandraDataAccessException(
"Can't add data with columnFamily = "
+ columnFamily
+ " and rowName="
+ row
+ " key = "
+ key);
}
try {
Mutator<String> mutator = HFactory.createMutator(keyspace, stringSerializer);
mutator.insert(
row, columnFamily, HFactory.createColumn(key, value, longSerializer, longSerializer));
mutator.execute();
} catch (Exception e) {
throw new CassandraDataAccessException("Error while adding long content to a row", e);
}
}
public void init() {
CassandraHostConfigurator hostConfig =
new CassandraHostConfigurator(darkStarNode + ":" + String.valueOf(darkStarPort));
cluster = HFactory.createCluster(clusterName, hostConfig);
keySpace = HFactory.createKeyspace(keyspace, cluster, policy);
mutator = HFactory.createMutator(keySpace, bfs);
}
/**
* Create a Cassandra Cluster instance given the connection details
*
* @param userName userName to connect to the cassandra
* @param password password to connect to cassandra
* @param clusterName Cluster name
* @param connectionString cassandra connection string
* @return Cluster instance
* @throws CassandraDataAccessException In case of and error in accessing database or data error
*/
public static Cluster createCluster(
String userName, String password, String clusterName, String connectionString)
throws CassandraDataAccessException {
if (userName == null || password == null) {
throw new CassandraDataAccessException(
"Can't create cluster with empty userName or Password");
}
if (clusterName == null) {
throw new CassandraDataAccessException("Can't create cluster with empty cluster name");
}
if (connectionString == null) {
throw new CassandraDataAccessException("Can't create cluster with empty connection string");
}
Map<String, String> credentials = new HashMap<String, String>();
credentials.put(USERNAME_KEY, userName);
credentials.put(PASSWORD_KEY, password);
CassandraHostConfigurator hostConfigurator = new CassandraHostConfigurator(connectionString);
hostConfigurator.setMaxActive(2000);
Cluster cluster = HFactory.getCluster(clusterName);
if (cluster == null) {
cluster = HFactory.createCluster(clusterName, hostConfigurator, credentials);
}
return cluster;
}
public void put(String columnFamily, String key, byte[] value) {
Mutator<String> mutator = HFactory.createMutator(this._keyspace, StringSerializer.get());
mutator.insert(
key,
columnFamily,
HFactory.createColumn(
DEFAULT_COLUMN_NAME, value, StringSerializer.get(), BytesArraySerializer.get()));
}
void setEnvironment() throws InvalidRequestException, TException {
try {
myCluster = HFactory.getOrCreateCluster("Test Sample", "localhost:9160");
ksdef = myCluster.describeKeyspace(keyspaceName);
if (ksdef == null) addKeyspacetoCassandra();
keyspace = HFactory.createKeyspace("mostkeyspace", myCluster);
} catch (Exception e) {
System.out.print("Unalble to setup environment");
e.printStackTrace();
}
}
void insertData(String dpname, Date d, Timestamp u, double value) {
try {
long timeInMicroSeconds = u.getTime();
// UUID timeUUIDColumnName = TimeUUIDUtils.getTimeUUID(timeInMicroSeconds);
System.out.println(d + "\t" + timeInMicroSeconds + "\t" + value);
DateSerializer ds = new DateSerializer();
Mutator<Date> mu = HFactory.createMutator(keyspace, ds);
mu.insert(d, dpname, HFactory.createColumn(timeInMicroSeconds, value));
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void insertTatamibotConfiguration(TatamibotConfiguration tatamibotConfiguration) {
UUID tatamibotConfigurationId = TimeUUIDUtils.getUniqueTimeUUIDinMillis();
Mutator<String> mutator = HFactory.createMutator(keyspaceOperator, StringSerializer.get());
mutator.insert(
tatamibotConfiguration.getDomain(),
ColumnFamilyKeys.DOMAIN_TATAMIBOT_CF,
HFactory.createColumn(
tatamibotConfigurationId, "", UUIDSerializer.get(), StringSerializer.get()));
tatamibotConfiguration.setTatamibotConfigurationId(tatamibotConfigurationId.toString());
em.persist(tatamibotConfiguration);
}
public void addFriends(String from_uname, List<String> to_unames) {
long timestamp = System.currentTimeMillis();
Mutator<String> mutator = cassandra.getMutator();
for (String uname : to_unames) {
mutator
.addInsertion(
from_uname, FRIENDS, HFactory.createStringColumn(uname, String.valueOf(timestamp)))
.addInsertion(
uname, FOLLOWERS, HFactory.createStringColumn(from_uname, String.valueOf(timestamp)))
.addCounter(from_uname, MISC_COUNTS, HFactory.createCounterColumn("friends", 1))
.addCounter(uname, MISC_COUNTS, HFactory.createCounterColumn("followers", 1));
}
mutator.execute();
}
@Override
@CacheEvict(value = "domain-tags-cache", key = "#domain")
public void addTag(String domain, String tag) {
HColumn<UUID, String> column =
HFactory.createColumn(
TimeUUIDUtils.getUniqueTimeUUIDinMillis(),
tag,
COLUMN_TTL,
UUIDSerializer.get(),
StringSerializer.get());
Mutator<String> mutator = HFactory.createMutator(keyspaceOperator, StringSerializer.get());
mutator.insert(domain, TRENDS_CF, column);
}
public static void deleteIntegerColumnFromRow(
String columnFamily, String row, Integer key, Keyspace keyspace)
throws CassandraDataAccessException {
if (keyspace == null) {
throw new CassandraDataAccessException("Can't delete Data , no keyspace provided ");
}
if (columnFamily == null || row == null) {
throw new CassandraDataAccessException(
"Can't delete data in columnFamily = "
+ columnFamily
+ " and rowName="
+ row
+ " key = "
+ key);
}
try {
Mutator<String> mutator = HFactory.createMutator(keyspace, stringSerializer);
mutator.addDeletion(row, columnFamily, key, integerSerializer);
mutator.execute();
} catch (Exception e) {
throw new CassandraDataAccessException("Error while deleting data", e);
}
}
public static List<String> getDestinationQueueNamesFromCounterColumns(
String columnFamilyName, String rowName, Keyspace keyspace)
throws CassandraDataAccessException {
ArrayList<String> rowList = new ArrayList<String>();
if (keyspace == null) {
throw new CassandraDataAccessException("Can't access Data , no keyspace provided ");
}
if (columnFamilyName == null || rowName == null) {
throw new CassandraDataAccessException(
"Can't access data with columnFamily =" + columnFamilyName + " and rowName=" + rowName);
}
try {
SliceCounterQuery<String, String> sliceQuery =
HFactory.createCounterSliceQuery(keyspace, stringSerializer, stringSerializer);
sliceQuery.setKey(rowName);
sliceQuery.setColumnFamily(columnFamilyName);
sliceQuery.setRange("", "", false, Integer.MAX_VALUE);
QueryResult<CounterSlice<String>> result = sliceQuery.execute();
CounterSlice<String> columnSlice = result.get();
for (HCounterColumn<String> column : columnSlice.getColumns()) {
rowList.add(column.getName());
}
} catch (Exception e) {
throw new CassandraDataAccessException(
"Error while accessing data from :" + columnFamilyName, e);
}
return rowList;
}
@Override
public String getLastRevision(String executionPlanIdentifier) {
ColumnSlice<String, byte[]> cs;
String rangeStart =
new StringBuffer(String.valueOf(timeAt1970.getTime())).append("_").toString();
boolean firstLoop = true;
while (true) {
SliceQuery<String, String, byte[]> q = HFactory.createSliceQuery(keyspace, sser, sser, bser);
q.setColumnFamily(INDEX_COLUMN_FAMILY_NAME)
.setKey(executionPlanIdentifier)
.setRange(rangeStart, String.valueOf(Long.MAX_VALUE), false, 1000);
QueryResult<ColumnSlice<String, byte[]>> r = q.execute();
cs = r.get();
int size = cs.getColumns().size();
if (firstLoop && size == 0) {
return null;
} else if (size == 0) {
return rangeStart;
} else {
firstLoop = false;
}
int lastIndex = size - 1;
rangeStart = cs.getColumns().get(lastIndex).getName();
if (size < 1000) {
break;
}
}
log.info("found revision " + rangeStart);
return rangeStart;
}
public static void addIntegerByteArrayContentToRaw(
String columnFamily,
String row,
int key,
byte[] value,
Mutator<String> mutator,
boolean execute)
throws CassandraDataAccessException {
if (mutator == null) {
throw new CassandraDataAccessException("Can't add Data , no Mutator provided ");
}
if (columnFamily == null || row == null || value == null) {
throw new CassandraDataAccessException(
"Can't add data with columnFamily = "
+ columnFamily
+ " and row="
+ row
+ " key = "
+ key
+ " value = "
+ value);
}
mutator.addInsertion(
row,
columnFamily,
HFactory.createColumn(key, value, integerSerializer, bytesArraySerializer));
if (execute) {
mutator.execute();
}
}
@Override
public Collection<TatamibotConfiguration> findTatamibotConfigurationsByDomain(String domain) {
Set<TatamibotConfiguration> configurations = new HashSet<TatamibotConfiguration>();
ColumnSlice<UUID, String> results =
HFactory.createSliceQuery(
keyspaceOperator,
StringSerializer.get(),
UUIDSerializer.get(),
StringSerializer.get())
.setColumnFamily(ColumnFamilyKeys.DOMAIN_TATAMIBOT_CF)
.setKey(domain)
.setRange(null, null, false, Integer.MAX_VALUE)
.execute()
.get();
for (HColumn<UUID, String> column : results.getColumns()) {
String tatamibotConfigurationId = column.getName().toString();
TatamibotConfiguration configuration =
em.find(TatamibotConfiguration.class, tatamibotConfigurationId);
configurations.add(configuration);
}
return configurations;
}
/**
* Get set of messages in a column family
*
* @param queueName QueueName
* @param columnFamilyName ColumnFamilyName
* @param keyspace Cassandra KeySpace
* @param count max message count limit
* @return ColumnSlice which contain the messages
* @throws CassandraDataAccessException
*/
public static ColumnSlice<Long, byte[]> getMessagesFromQueue(
String queueName, String columnFamilyName, Keyspace keyspace, int count)
throws CassandraDataAccessException {
if (keyspace == null) {
throw new CassandraDataAccessException("Can't access Data , no keyspace provided ");
}
if (columnFamilyName == null || queueName == null) {
throw new CassandraDataAccessException(
"Can't access data with columnFamily = "
+ columnFamilyName
+ " and queueName="
+ queueName);
}
try {
SliceQuery<String, Long, byte[]> sliceQuery =
HFactory.createSliceQuery(
keyspace, stringSerializer, longSerializer, bytesArraySerializer);
sliceQuery.setKey(queueName);
sliceQuery.setRange((long) 0, Long.MAX_VALUE, false, count);
sliceQuery.setColumnFamily(columnFamilyName);
QueryResult<ColumnSlice<Long, byte[]>> result = sliceQuery.execute();
ColumnSlice<Long, byte[]> columnSlice = result.get();
return columnSlice;
} catch (Exception e) {
throw new CassandraDataAccessException(
"Error while getting data from " + columnFamilyName, e);
}
}
/**
* Get a HColumn<Long, byte[]> with a given key in a given row in a given column Family
*
* @param rowName name of the row
* @param columnFamily column Family name
* @param key long type key of the column we are looking for
* @param keyspace cassandra keySpace instance
* @return query result as a cassandra column
* @throws CassandraDataAccessException in case of an Error when accessing data
*/
public static HColumn<Long, byte[]> getLongByteArrayColumnInARow(
String rowName, String columnFamily, long key, Keyspace keyspace)
throws CassandraDataAccessException {
if (keyspace == null) {
throw new CassandraDataAccessException("Can't access Data , no keyspace provided ");
}
if (columnFamily == null || rowName == null) {
throw new CassandraDataAccessException(
"Can't access data with columnFamily = " + columnFamily + " and rowName=" + rowName);
}
try {
ColumnQuery columnQuery =
HFactory.createColumnQuery(
keyspace, stringSerializer, longSerializer, bytesArraySerializer);
columnQuery.setColumnFamily(columnFamily);
columnQuery.setKey(rowName);
columnQuery.setName(key);
QueryResult<HColumn<Long, byte[]>> result = columnQuery.execute();
HColumn<Long, byte[]> column = result.get();
return column;
} catch (Exception e) {
throw new CassandraDataAccessException(
"Error while executing quary for HColumn<Long, byte[]> with key ="
+ key
+ " in column Family = "
+ columnFamily,
e);
}
}
/**
* Get Number of <String,String> type columns in a given row in a cassandra column family
*
* @param rowName row Name we are querying for
* @param columnFamilyName columnFamilName
* @param keyspace
* @param count
* @return
*/
public static ColumnSlice<String, String> getStringTypeColumnsInARow(
String rowName, String columnFamilyName, Keyspace keyspace, int count)
throws CassandraDataAccessException {
if (keyspace == null) {
throw new CassandraDataAccessException("Can't access Data , no keyspace provided ");
}
if (columnFamilyName == null || rowName == null) {
throw new CassandraDataAccessException(
"Can't access data with columnFamily = " + columnFamilyName + " and rowName=" + rowName);
}
try {
SliceQuery sliceQuery =
HFactory.createSliceQuery(keyspace, stringSerializer, stringSerializer, stringSerializer);
sliceQuery.setKey(rowName);
sliceQuery.setColumnFamily(columnFamilyName);
sliceQuery.setRange("", "", false, count);
QueryResult<ColumnSlice<String, String>> result = sliceQuery.execute();
ColumnSlice<String, String> columnSlice = result.get();
return columnSlice;
} catch (Exception e) {
throw new CassandraDataAccessException(
"Error while getting data from : " + columnFamilyName, e);
}
}
@Override
public PersistenceObject load(
PersistenceManagementEvent persistenceManagementEvent, String nodeId) {
List<NodeSnapshot> list = new ArrayList<NodeSnapshot>();
ColumnSlice<String, byte[]> cs;
SliceQuery<String, String, byte[]> q = HFactory.createSliceQuery(keyspace, sser, sser, bser);
q.setColumnFamily(COLUMN_FAMILY_NAME)
.setKey(persistenceManagementEvent.getRevision())
.setRange("", "", false, 1000)
.setColumnNames(nodeId);
QueryResult<ColumnSlice<String, byte[]>> r = q.execute();
cs = r.get();
PersistenceObject persistenceObject = null;
for (HColumn<String, byte[]> hc : cs.getColumns()) {
persistenceObject = (PersistenceObject) ByteSerializer.BToO(hc.getValue());
// list.add(new NodeSnapshot(hc.getName(), hc.getValue()));
}
// return list;
return persistenceObject;
}
/**
* Counts columns in the specified range of a standard column family
*
* @param key
* @param start
* @param end
* @param max
* @return
*/
public int countColumns(K key, N start, N end, int max) {
CountQuery<K, N> query = HFactory.createCountQuery(keyspace, keySerializer, topSerializer);
query.setKey(key);
query.setColumnFamily(columnFamily);
query.setRange(start, end, max);
return query.execute().get();
}
private List<String> getTags(
Keyspace keyspaceOperator,
String columnfamily,
String cfId,
String startRange,
String endRange) {
SliceQuery<String, String, String> query =
HFactory.createSliceQuery(
keyspaceOperator,
StringSerializer.get(),
StringSerializer.get(),
StringSerializer.get())
.setColumnFamily(columnfamily)
.setKey(cfId)
.setRange(TAG_COLUMN_MIN_NAME, TAG_COLUMN_MAX_NAME, false, Integer.MAX_VALUE);
QueryResult<ColumnSlice<String, String>> queryResult = query.execute();
ColumnSlice<String, String> columnSlice = queryResult.get();
SortedSet<String> tags = new TreeSet<String>();
for (HColumn<String, String> hColumn : columnSlice.getColumns()) {
tags.add(hColumn.getValue());
}
return new ArrayList<String>(tags);
}
public void runQuery() throws IOException {
MultigetSliceQuery<DataPointsRowKey, Integer, ByteBuffer> msliceQuery =
HFactory.createMultigetSliceQuery(
m_keyspace, ROW_KEY_SERIALIZER, IntegerSerializer.get(), ByteBufferSerializer.get());
msliceQuery.setColumnFamily(m_columnFamily);
msliceQuery.setKeys(m_rowKeys);
if (m_descending) msliceQuery.setRange(m_endTime, m_startTime, true, m_multiRowReadSize);
else msliceQuery.setRange(m_startTime, m_endTime, false, m_multiRowReadSize);
Rows<DataPointsRowKey, Integer, ByteBuffer> rows = msliceQuery.execute().get();
List<Row<DataPointsRowKey, Integer, ByteBuffer>> unfinishedRows =
new ArrayList<Row<DataPointsRowKey, Integer, ByteBuffer>>();
for (Row<DataPointsRowKey, Integer, ByteBuffer> row : rows) {
List<HColumn<Integer, ByteBuffer>> columns = row.getColumnSlice().getColumns();
if (!m_limit && columns.size() == m_multiRowReadSize) unfinishedRows.add(row);
writeColumns(row.getKey(), columns);
}
// Iterate through the unfinished rows and get the rest of the data.
// todo: use multiple threads to retrieve this data
for (Row<DataPointsRowKey, Integer, ByteBuffer> unfinishedRow : unfinishedRows) {
DataPointsRowKey key = unfinishedRow.getKey();
SliceQuery<DataPointsRowKey, Integer, ByteBuffer> sliceQuery =
HFactory.createSliceQuery(
m_keyspace, ROW_KEY_SERIALIZER, IntegerSerializer.get(), ByteBufferSerializer.get());
sliceQuery.setColumnFamily(m_columnFamily);
sliceQuery.setKey(key);
List<HColumn<Integer, ByteBuffer>> columns = unfinishedRow.getColumnSlice().getColumns();
do {
Integer lastTime = columns.get(columns.size() - 1).getName();
if (m_descending) sliceQuery.setRange(lastTime - 1, m_startTime, true, m_singleRowReadSize);
else sliceQuery.setRange(lastTime + 1, m_endTime, false, m_singleRowReadSize);
columns = sliceQuery.execute().get().getColumns();
writeColumns(key, columns);
} while (columns.size() == m_singleRowReadSize);
}
}
public void addEventSoftState(EventSoftState state) {
Mutator<String> mutator = getStringMutator();
mutator.addInsertion(
state.getResourceURL(),
EVENT_SOFT_STATE_COLUMN_FAMILY_NAME,
HFactory.createColumn(state.getEntityTag(), state, STRING_SERIALIZER, OBJECT_SERIALIZER));
mutator.execute();
}
public static <A, B> HColumn<A, B> column(final A name, final B value) {
return HFactory.createColumn(
name, //
value, //
(Serializer<A>) SerializerTypeInferer.getSerializer(name), //
(Serializer<B>) SerializerTypeInferer.getSerializer(value));
}
private void insertSubscription(SubscriptionContext context) {
Mutator<Object> mutator = getObjectMutator();
mutator.addInsertion(
context.getId(),
SUBSCRIPTION_COLUMN_FAMILY_NAME,
HFactory.createColumn("value", context, STRING_SERIALIZER, OBJECT_SERIALIZER));
mutator.execute();
}
public void truncate() {
Mutator<K> mutator = HFactory.createMutator(keyspace, keySerializer);
Iterator<K> iterator = new KeyIterator<K>(keyspace, columnFamily, keySerializer).iterator();
while (iterator.hasNext()) {
this.removeRowBatch(iterator.next(), mutator);
}
this.executeMutator(mutator);
}
public void removeCounterRow(K key) {
SliceCounterQuery<K, N> query =
HFactory.createCounterSliceQuery(keyspace, keySerializer, columnNameSerializer)
.setColumnFamily(columnFamily)
.setKey(key);
AchillesCounterSliceIterator<K, N> iterator =
new AchillesCounterSliceIterator<K, N>(
policy, columnFamily, query, (N) null, (N) null, false, DEFAULT_LENGTH);
Mutator<K> mutator = HFactory.createMutator(keyspace, keySerializer);
while (iterator.hasNext()) {
HCounterColumn<N> counterCol = iterator.next();
mutator.decrementCounter(key, columnFamily, counterCol.getName(), counterCol.getValue());
}
this.executeMutator(mutator);
}