net.e6tech.elements.cassandra.etl

Class PartitionOrderByStrategy<S extends PartitionOrderBy>

java.lang.Object

net.e6tech.elements.cassandra.etl.PartitionStrategy<S,PartitionOrderByContext>

net.e6tech.elements.cassandra.etl.PartitionOrderByStrategy<S>

All Implemented Interfaces:

BatchStrategy<S,PartitionOrderByContext>, Strategy<PartitionOrderByContext>

public class PartitionOrderByStrategy<S extends PartitionOrderBy>
extends PartitionStrategy<S,PartitionOrderByContext>

This interface is designed to extract data from a Cassandra table to another Cassandra table. The source table (class) must implement C4HourlyId. the idea is to get distinct creation hours from the source table and import the data in chunks based on order by id.

Field Summary

Fields inherited from interface net.e6tech.elements.cassandra.etl.Strategy

logger

Constructor Summary

Constructors

Constructor and Description
PartitionOrderByStrategy()

Method Summary

Modifier and Type	Method and Description
java.util.List<S>	extract(PartitionOrderByContext context)
int	run(PartitionOrderByContext context, java.util.List<java.lang.Comparable> partitions)

Methods inherited from class net.e6tech.elements.cassandra.etl.PartitionStrategy

load, queryPartitions, queryRange, run, runPartitions, runPartitions

Methods inherited from class java.lang.Object

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

Constructor Detail

PartitionOrderByStrategy

public PartitionOrderByStrategy()

Method Detail

extract

public java.util.List<S> extract(PartitionOrderByContext context)

Specified by:

extract in interface BatchStrategy<S extends PartitionOrderBy,PartitionOrderByContext>

Overrides:

extract in class PartitionStrategy<S extends PartitionOrderBy,PartitionOrderByContext>

Parameters:

context - PartitionOrderByContext

Returns:

a list of data ordered by partition key. It is very important that the list is ordered by the partition key so that in case of failures the system can recover correctly.

run

public int run(PartitionOrderByContext context,
               java.util.List<java.lang.Comparable> partitions)

Overrides:

run in class PartitionStrategy<S extends PartitionOrderBy,PartitionOrderByContext>