org.apache.storm.cassandra.trident.state

Class CassandraBackingMap<T>

java.lang.Object

org.apache.storm.cassandra.trident.state.CassandraBackingMap<T>

All Implemented Interfaces:

IBackingMap<T>

public class CassandraBackingMap<T>
extends Object
implements IBackingMap<T>

An IBackingState implementation for Cassandra.

The implementation stores state as a binary blob in cassandra using a Serializer. It supports Opaque, Transactional and NonTransactional states, given a matching serializer.

Configuration is done with three separate constructs: - One tuple mapper for multiGet, which should map keys to a select statement and return Values. - One state mapper, which maps the state to/from a Values representation, which is used for binding. - One tuple mapper for multiPut, which should map Values to an INSERT or UPDATE statement.

multiPut(List, List) updates Cassandra with parallel statements. multiGet(List) queries Cassandra with parallel statements.

Parallelism defaults to half the maximum requests per host, either local or remote whichever is lower. The driver defaults to 256 for remote hosts and 1024 for local hosts, so the default value is 128 unless the driver is configured otherwise.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CassandraBackingMap.Options<T>

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	CassandraBackingMap(Map<String,Object> conf, CassandraBackingMap.Options<T> options)

Method Summary

Modifier and Type	Method and Description
List<T>	multiGet(List<List<Object>> keys)
void	multiPut(List<List<Object>> keys, List<T> values)
void	prepare()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CassandraBackingMap

protected CassandraBackingMap(Map<String,Object> conf,
                              CassandraBackingMap.Options<T> options)

Method Detail

prepare

public void prepare()

multiGet

public List<T> multiGet(List<List<Object>> keys)

Specified by:

multiGet in interface IBackingMap<T>

multiPut

public void multiPut(List<List<Object>> keys,
                     List<T> values)

Specified by:

multiPut in interface IBackingMap<T>