org.apache.beam.sdk.io.cassandra

Class CassandraServiceImpl<T>

java.lang.Object

org.apache.beam.sdk.io.cassandra.CassandraServiceImpl<T>

All Implemented Interfaces:

Serializable, CassandraService<T>

public class CassandraServiceImpl<T>
extends Object
implements CassandraService<T>

An implementation of the CassandraService that actually use a Cassandra instance.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	CassandraServiceImpl.TokenRange Represent a token range in Cassandra instance, wrapping the partition count, size and token range.
protected class	CassandraServiceImpl.WriterImpl<T> Writer storing an entity into Apache Cassandra database.

Nested classes/interfaces inherited from interface org.apache.beam.sdk.io.cassandra.CassandraService

CassandraService.Writer<T>

Constructor Summary

Constructors

Constructor and Description
CassandraServiceImpl()

Method Summary

Modifier and Type	Method and Description
org.apache.beam.sdk.io.cassandra.CassandraServiceImpl.CassandraReaderImpl<T>	createReader(org.apache.beam.sdk.io.cassandra.CassandraIO.CassandraSource<T> source) Returns a BoundedSource.BoundedReader that will read from Cassandra using the spec from CassandraIO.CassandraSource.
CassandraService.Writer	createWriter(CassandraIO.Write<T> spec) Create a CassandraService.Writer that writes entities into the Cassandra instance.
protected static BigInteger	distance(long left, long right) Measure distance between two tokens.
long	getEstimatedSizeBytes(CassandraIO.Read<T> spec) Returns an estimation of the size that could be read.
protected static long	getEstimatedSizeBytes(List<CassandraServiceImpl.TokenRange> tokenRanges) Actually estimate the size of the data to read on the cluster, based on the given token ranges to address.
protected static double	getRingFraction(List<CassandraServiceImpl.TokenRange> tokenRanges) Compute the percentage of token addressed compared with the whole tokens in the cluster.
protected static boolean	isMurmur3Partitioner(com.datastax.driver.core.Cluster cluster) Check if the current partitioner is the Murmur3 (default in Cassandra version newer than 2).
List<BoundedSource<T>>	split(CassandraIO.Read<T> spec, long desiredBundleSizeBytes) Split a table read into several sources.
protected List<BoundedSource<T>>	split(CassandraIO.Read<T> spec, long desiredBundleSizeBytes, long estimatedSizeBytes) Compute the number of splits based on the estimated size and the desired bundle size, and create several sources.

Methods inherited from class java.lang.Object

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

Constructor Detail

CassandraServiceImpl

public CassandraServiceImpl()

Method Detail

createReader

public org.apache.beam.sdk.io.cassandra.CassandraServiceImpl.CassandraReaderImpl<T> createReader(org.apache.beam.sdk.io.cassandra.CassandraIO.CassandraSource<T> source)

Description copied from interface: CassandraService

Returns a BoundedSource.BoundedReader that will read from Cassandra using the spec from CassandraIO.CassandraSource.

Specified by:

createReader in interface CassandraService<T>

getEstimatedSizeBytes

public long getEstimatedSizeBytes(CassandraIO.Read<T> spec)

Description copied from interface: CassandraService

Returns an estimation of the size that could be read.

Specified by:

getEstimatedSizeBytes in interface CassandraService<T>

getEstimatedSizeBytes

protected static long getEstimatedSizeBytes(List<CassandraServiceImpl.TokenRange> tokenRanges)

Actually estimate the size of the data to read on the cluster, based on the given token ranges to address.

split

public List<BoundedSource<T>> split(CassandraIO.Read<T> spec,
                                    long desiredBundleSizeBytes)

Description copied from interface: CassandraService

Split a table read into several sources.

Specified by:

split in interface CassandraService<T>

split

protected List<BoundedSource<T>> split(CassandraIO.Read<T> spec,
                                       long desiredBundleSizeBytes,
                                       long estimatedSizeBytes)

Compute the number of splits based on the estimated size and the desired bundle size, and create several sources.

getRingFraction

protected static double getRingFraction(List<CassandraServiceImpl.TokenRange> tokenRanges)

Compute the percentage of token addressed compared with the whole tokens in the cluster.

distance

protected static BigInteger distance(long left,
                                     long right)

Measure distance between two tokens.

isMurmur3Partitioner

protected static boolean isMurmur3Partitioner(com.datastax.driver.core.Cluster cluster)

Check if the current partitioner is the Murmur3 (default in Cassandra version newer than 2).

createWriter

public CassandraService.Writer createWriter(CassandraIO.Write<T> spec)

Description copied from interface: CassandraService

Create a CassandraService.Writer that writes entities into the Cassandra instance.

Specified by:

createWriter in interface CassandraService<T>