com.hazelcast.mapreduce.impl

Class AbstractJob.ReducingJobImpl<EntryKey,Key,Value>

java.lang.Object

com.hazelcast.mapreduce.impl.AbstractJob.ReducingJobImpl<EntryKey,Key,Value>

Type Parameters:

EntryKey - type of the original base key

Key - type of the key at that processing state

Value - type of the value at that processing state

All Implemented Interfaces:

ReducingJob<EntryKey,Key,Value>

Enclosing class:

AbstractJob<KeyIn,ValueIn>

protected class AbstractJob.ReducingJobImpl<EntryKey,Key,Value>
extends Object
implements ReducingJob<EntryKey,Key,Value>

This class is just used to comply to the public DSL style API

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractJob.ReducingJobImpl()

Method Summary

Methods

Modifier and Type	Method and Description
ReducingJob<EntryKey,Key,Value>	chunkSize(int chunkSize) Defines the number of elements per chunk.
ReducingJob<EntryKey,Key,Value>	keyPredicate(KeyPredicate<EntryKey> predicate) Defines the KeyPredicate implementation to preselect keys the MapReduce task will be executed on.
ReducingJob<EntryKey,Key,Value>	onKeys(EntryKey... keys) Defines keys to execute the mapper and a possibly defined reducer against.
ReducingJob<EntryKey,Key,Value>	onKeys(Iterable<EntryKey> keys) Defines keys to execute the mapper and a possibly defined reducer against.
<ValueOut> ReducingSubmittableJob<EntryKey,Key,ValueOut>	reducer(ReducerFactory<Key,Value,ValueOut> reducerFactory) Defines the ReducerFactory for this task.
JobCompletableFuture<Map<Key,List<Value>>>	submit() Submits the task to Hazelcast and executes the defined mapper and reducer on all cluster nodes
<ValueOut> JobCompletableFuture<ValueOut>	submit(Collator<Map.Entry<Key,List<Value>>,ValueOut> collator) Submits the task to Hazelcast and executes the defined mapper and reducer on all cluster nodes and executes the collator before returning the final result.
ReducingJob<EntryKey,Key,Value>	topologyChangedStrategy(TopologyChangedStrategy topologyChangedStrategy) Defines the strategy to handle topology changes while executing the map reduce job.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractJob.ReducingJobImpl

protected AbstractJob.ReducingJobImpl()

Method Detail

reducer

public <ValueOut> ReducingSubmittableJob<EntryKey,Key,ValueOut> reducer(ReducerFactory<Key,Value,ValueOut> reducerFactory)

Description copied from interface: ReducingJob

Defines the ReducerFactory for this task. This method is not idempotent and is callable only one time. Further calls result in an IllegalStateException to be thrown telling you to not change the internal state.

Specified by:

reducer in interface ReducingJob<EntryKey,Key,Value>

Type Parameters:

ValueOut - type of the reduced value

Parameters:

reducerFactory - ReducerFactory to build Reducers

Returns:

instance of this Job with generics changed on usage

onKeys

public ReducingJob<EntryKey,Key,Value> onKeys(Iterable<EntryKey> keys)

Description copied from interface: ReducingJob

Defines keys to execute the mapper and a possibly defined reducer against. If keys are known before submitting the task setting them can improve execution speed.

Specified by:

onKeys in interface ReducingJob<EntryKey,Key,Value>

Parameters:

keys - keys to be executed against

Returns:

instance of this Job with generics changed on usage

onKeys

public ReducingJob<EntryKey,Key,Value> onKeys(EntryKey... keys)

Description copied from interface: ReducingJob

Defines keys to execute the mapper and a possibly defined reducer against. If keys are known before submitting the task setting them can improve execution speed.

Specified by:

onKeys in interface ReducingJob<EntryKey,Key,Value>

Parameters:

keys - keys to be executed against

Returns:

instance of this Job with generics changed on usage

keyPredicate

public ReducingJob<EntryKey,Key,Value> keyPredicate(KeyPredicate<EntryKey> predicate)

Description copied from interface: ReducingJob

Defines the KeyPredicate implementation to preselect keys the MapReduce task will be executed on. Preselecting keys can speed up the job massively.
This method can be used in conjunction with ReducingJob.onKeys(Iterable) or ReducingJob.onKeys(Object...) to define a range of known and evaluated keys.

Specified by:

keyPredicate in interface ReducingJob<EntryKey,Key,Value>

Parameters:

predicate - predicate implementation to be used to evaluate keys

Returns:

instance of this Job with generics changed on usage

chunkSize

public ReducingJob<EntryKey,Key,Value> chunkSize(int chunkSize)

Description copied from interface: ReducingJob

Defines the number of elements per chunk. Whenever the chunk size is reached and a ReducerFactory is defined the chunk will be send to the nodes that is responsible for the emitted keys.
Please note, that chunks are deactivated when no ReducerFactory is defined

Specified by:

chunkSize in interface ReducingJob<EntryKey,Key,Value>

Parameters:

chunkSize - the number of elements per chunk

Returns:

instance of this Job with generics changed on usage

topologyChangedStrategy

public ReducingJob<EntryKey,Key,Value> topologyChangedStrategy(TopologyChangedStrategy topologyChangedStrategy)

Description copied from interface: ReducingJob

Defines the strategy to handle topology changes while executing the map reduce job. For further information see TopologyChangedStrategy.

Specified by:

topologyChangedStrategy in interface ReducingJob<EntryKey,Key,Value>

Parameters:

topologyChangedStrategy - strategy to use

Returns:

instance of this Job with generics changed on usage

submit

public JobCompletableFuture<Map<Key,List<Value>>> submit()

Description copied from interface: ReducingJob

Submits the task to Hazelcast and executes the defined mapper and reducer on all cluster nodes

Specified by:

submit in interface ReducingJob<EntryKey,Key,Value>

Returns:

JobCompletableFuture to wait for mapped and possibly reduced result

submit

public <ValueOut> JobCompletableFuture<ValueOut> submit(Collator<Map.Entry<Key,List<Value>>,ValueOut> collator)

Description copied from interface: ReducingJob

Submits the task to Hazelcast and executes the defined mapper and reducer on all cluster nodes and executes the collator before returning the final result.

Specified by:

submit in interface ReducingJob<EntryKey,Key,Value>

Type Parameters:

ValueOut - type of the collated value

Parameters:

collator - collator to use after map and reduce

Returns:

JobCompletableFuture to wait for mapped and possibly reduced result