com.hazelcast.mapreduce.MappingJob Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.mapreduce;
import java.util.List;
import java.util.Map;
/**
*
* This interface describes a mapping mapreduce Job.
* For further information see {@link Job}.
*
*
* @param type of the original input key
* @param type of key used as input key type
* @param type of value used as input value type
* @see com.hazelcast.mapreduce.Job
* @since 3.2
* @deprecated MapReduce is deprecated and will be removed in 4.0.
* For map aggregations, you can use {@link com.hazelcast.aggregation.Aggregator} on IMap.
* For general data processing, it is superseded by Hazelcast Jet.
*/
@Deprecated
public interface MappingJob {
/**
* 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.
*
* @param keys keys to be executed against
* @return instance of this Job with generics changed on usage
*/
MappingJob onKeys(Iterable keys);
/**
* 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.
*
* @param keys keys to be executed against
* @return instance of this Job with generics changed on usage
*/
MappingJob onKeys(EntryKey... keys);
/**
* Defines the {@link KeyPredicate} implementation to preselect keys that the MapReduce task will be executed on.
* Preselecting keys can speed up the job massively.
* This method can be used in conjunction with {@link #onKeys(Iterable)} or {@link #onKeys(Object...)} to define a
* range of known and evaluated keys.
*
* @param predicate predicate implementation to be used to evaluate keys
* @return instance of this Job with generics changed on usage
*/
MappingJob keyPredicate(KeyPredicate predicate);
/**
* Defines the number of elements per chunk. Whenever the chunk size is reached and a
* {@link com.hazelcast.mapreduce.ReducerFactory} is defined, the chunk will be sent to the nodes that
* are responsible for the emitted keys.
* Please note, that chunks are deactivated when no ReducerFactory is defined
*
* @param chunkSize the number of elements per chunk
* @return instance of this Job with generics changed on usage
*/
MappingJob chunkSize(int chunkSize);
/**
* Defines the strategy to handle topology changes while executing the map reduce job. For further
* information see {@link com.hazelcast.mapreduce.TopologyChangedStrategy}.
*
* @param topologyChangedStrategy strategy to use
* @return instance of this Job with generics changed on usage
*/
MappingJob topologyChangedStrategy(TopologyChangedStrategy topologyChangedStrategy);
/**
* Defines the {@link CombinerFactory} for this task. This method is not idempotent and is callable only one time.
* Further calls result in an {@link IllegalStateException} thrown telling you to not change the internal state.
*
* @param combinerFactory CombinerFactory to build Combiner
* @param type of the combined value
* @return instance of this Job with generics changed on usage
*/
ReducingJob combiner(
CombinerFactory combinerFactory);
/**
* Defines the {@link ReducerFactory} for this task. This method is not idempotent and is callable only one time.
* Further calls result in an {@link IllegalStateException} thrown telling you to not change the internal state.
*
* @param reducerFactory ReducerFactory to build Reducers
* @param type of the reduced value
* @return instance of this Job with generics changed on usage
*/
ReducingSubmittableJob reducer(
ReducerFactory reducerFactory);
/**
* Submits the task to Hazelcast and executes the defined mapper and reducer on all cluster nodes.
*
* @return JobCompletableFuture to wait for mapped and possibly reduced result
*/
JobCompletableFuture>> submit();
/**
* Submits the task to Hazelcast, executes the defined mapper and reducer on all cluster nodes, and executes the
* collator before returning the final result.
*
* @param collator collator to use after map and reduce
* @param type of the collated value
* @return JobCompletableFuture to wait for mapped and possibly reduced result
*/
JobCompletableFuture submit(Collator>, ValueOut> collator);
}