org.apache.tez.mapreduce.common.MRInputSplitDistributor.java Source code

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Here is the source code for org.apache.tez.mapreduce.common.MRInputSplitDistributor.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.tez.mapreduce.common;

import java.io.IOException;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience.Public;
import org.apache.hadoop.classification.InterfaceStability.Evolving;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapred.JobConf;
import org.apache.tez.common.TezUtils;
import org.apache.tez.dag.api.Vertex;
import org.apache.tez.mapreduce.hadoop.MRInputHelpers;
import org.apache.tez.mapreduce.hadoop.MRJobConfig;
import org.apache.tez.mapreduce.lib.MRInputUtils;
import org.apache.tez.mapreduce.protos.MRRuntimeProtos.MRInputUserPayloadProto;
import org.apache.tez.mapreduce.protos.MRRuntimeProtos.MRSplitProto;
import org.apache.tez.mapreduce.protos.MRRuntimeProtos.MRSplitsProto;
import org.apache.tez.runtime.api.Event;
import org.apache.tez.runtime.api.InputInitializer;
import org.apache.tez.runtime.api.InputInitializerContext;
import org.apache.tez.runtime.api.events.InputDataInformationEvent;
import org.apache.tez.runtime.api.events.InputInitializerEvent;
import org.apache.tez.runtime.api.events.InputUpdatePayloadEvent;

import com.google.common.base.Stopwatch;
import com.google.common.collect.Lists;

/**
 * Implements an {@link InputInitializer} that distributes Map Reduce 
 * splits created by the client to tasks in the {@link Vertex}
 * This can be used when certain reasons (e.g. security) prevent splits
 * from being produced in the App Master via {@link MRInputAMSplitGenerator}
 * and splits must be produced at the client. They can still be distributed
 * intelligently among tasks at runtime using this.
 */
@Public
@Evolving
public class MRInputSplitDistributor extends InputInitializer {

    private static final Log LOG = LogFactory.getLog(MRInputSplitDistributor.class);

    private boolean sendSerializedEvents;

    private MRSplitsProto splitsProto;

    public MRInputSplitDistributor(InputInitializerContext initializerContext) {
        super(initializerContext);
    }

    @Override
    public List<Event> initialize() throws IOException {
        Stopwatch sw = null;
        if (LOG.isDebugEnabled()) {
            sw = new Stopwatch().start();
        }
        MRInputUserPayloadProto userPayloadProto = MRInputHelpers
                .parseMRInputPayload(getContext().getInputUserPayload());
        if (LOG.isDebugEnabled()) {
            sw.stop();
            LOG.debug("Time to parse MRInput payload into prot: " + sw.elapsedMillis());
        }
        Configuration conf = TezUtils.createConfFromByteString(userPayloadProto.getConfigurationBytes());
        JobConf jobConf = new JobConf(conf);
        boolean useNewApi = jobConf.getUseNewMapper();
        sendSerializedEvents = conf.getBoolean(MRJobConfig.MR_TEZ_INPUT_INITIALIZER_SERIALIZE_EVENT_PAYLOAD,
                MRJobConfig.MR_TEZ_INPUT_INITIALIZER_SERIALIZE_EVENT_PAYLOAD_DEFAULT);
        LOG.info("Emitting serialized splits: " + sendSerializedEvents);

        this.splitsProto = userPayloadProto.getSplits();

        MRInputUserPayloadProto.Builder updatedPayloadBuilder = MRInputUserPayloadProto
                .newBuilder(userPayloadProto);
        updatedPayloadBuilder.clearSplits();

        List<Event> events = Lists.newArrayListWithCapacity(this.splitsProto.getSplitsCount() + 1);
        InputUpdatePayloadEvent updatePayloadEvent = InputUpdatePayloadEvent
                .create(updatedPayloadBuilder.build().toByteString().asReadOnlyByteBuffer());

        events.add(updatePayloadEvent);
        int count = 0;

        for (MRSplitProto mrSplit : this.splitsProto.getSplitsList()) {

            InputDataInformationEvent diEvent;

            if (sendSerializedEvents) {
                // Unnecessary array copy, can be avoided by using ByteBuffer instead of
                // a raw array.
                diEvent = InputDataInformationEvent.createWithSerializedPayload(count++,
                        mrSplit.toByteString().asReadOnlyByteBuffer());
            } else {
                if (useNewApi) {
                    org.apache.hadoop.mapreduce.InputSplit newInputSplit = MRInputUtils
                            .getNewSplitDetailsFromEvent(mrSplit, conf);
                    diEvent = InputDataInformationEvent.createWithObjectPayload(count++, newInputSplit);
                } else {
                    org.apache.hadoop.mapred.InputSplit oldInputSplit = MRInputUtils
                            .getOldSplitDetailsFromEvent(mrSplit, conf);
                    diEvent = InputDataInformationEvent.createWithObjectPayload(count++, oldInputSplit);
                }
            }
            events.add(diEvent);
        }

        return events;
    }

    @Override
    public void handleInputInitializerEvent(List<InputInitializerEvent> events) throws Exception {
        throw new UnsupportedOperationException("Not expecting to handle any events");
    }
}