org.apache.cassandra.hadoop
Class ConfigHelper

java.lang.Object
  org.apache.cassandra.hadoop.ConfigHelper

public class ConfigHelper
extends java.lang.Object

Constructor Summary

ConfigHelper()

Method Summary

static java.lang.String	getColumnFamily(org.apache.hadoop.conf.Configuration conf)
static int	getInputSplitSize(org.apache.hadoop.conf.Configuration conf)
static java.lang.String	getKeyspace(org.apache.hadoop.conf.Configuration conf)
static int	getRangeBatchSize(org.apache.hadoop.conf.Configuration conf) The number of rows to request with each get range slices request.
static org.apache.cassandra.thrift.SlicePredicate	getSlicePredicate(org.apache.hadoop.conf.Configuration conf)
static void	setColumnFamily(org.apache.hadoop.conf.Configuration conf, java.lang.String keyspace, java.lang.String columnFamily) Set the keyspace and column family for this job.
static void	setInputSplitSize(org.apache.hadoop.conf.Configuration conf, int splitsize) Set the size of the input split.
static void	setRangeBatchSize(org.apache.hadoop.conf.Configuration conf, int batchsize) The number of rows to request with each get range slices request.
static void	setSlicePredicate(org.apache.hadoop.conf.Configuration conf, org.apache.cassandra.thrift.SlicePredicate predicate) Set the predicate that determines what columns will be selected from each row.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConfigHelper

public ConfigHelper()

Method Detail

setColumnFamily

public static void setColumnFamily(org.apache.hadoop.conf.Configuration conf,
                                   java.lang.String keyspace,
                                   java.lang.String columnFamily)

Set the keyspace and column family for this job.

Parameters:

conf - Job configuration you are about to run

keyspace -

columnFamily -

setRangeBatchSize

public static void setRangeBatchSize(org.apache.hadoop.conf.Configuration conf,
                                     int batchsize)

The number of rows to request with each get range slices request. Too big and you can either get timeouts when it takes Cassandra too long to fetch all the data. Too small and the performance will be eaten up by the overhead of each request.

Parameters:

conf - Job configuration you are about to run

batchsize - Number of rows to request each time

getRangeBatchSize

public static int getRangeBatchSize(org.apache.hadoop.conf.Configuration conf)

The number of rows to request with each get range slices request. Too big and you can either get timeouts when it takes Cassandra too long to fetch all the data. Too small and the performance will be eaten up by the overhead of each request.

Parameters:

conf - Job configuration you are about to run

Returns:

Number of rows to request each time

setInputSplitSize

public static void setInputSplitSize(org.apache.hadoop.conf.Configuration conf,
                                     int splitsize)

Set the size of the input split. This affects the number of maps created, if the number is too small the overhead of each map will take up the bulk of the job time.

Parameters:

conf - Job configuration you are about to run

splitsize - Size of the input split

getInputSplitSize

public static int getInputSplitSize(org.apache.hadoop.conf.Configuration conf)

setSlicePredicate

public static void setSlicePredicate(org.apache.hadoop.conf.Configuration conf,
                                     org.apache.cassandra.thrift.SlicePredicate predicate)

Set the predicate that determines what columns will be selected from each row.

Parameters:

conf - Job configuration you are about to run

predicate -

getSlicePredicate

public static org.apache.cassandra.thrift.SlicePredicate getSlicePredicate(org.apache.hadoop.conf.Configuration conf)

getKeyspace

public static java.lang.String getKeyspace(org.apache.hadoop.conf.Configuration conf)

getColumnFamily

public static java.lang.String getColumnFamily(org.apache.hadoop.conf.Configuration conf)