org.springframework.yarn.batch.partition.HdfsSplitBatchPartitionHandler.java Source code

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Here is the source code for org.springframework.yarn.batch.partition.HdfsSplitBatchPartitionHandler.java

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/*
 * Copyright 2013 the original author or authors.
 *
 * 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 org.springframework.yarn.batch.partition;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.BlockLocation;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.springframework.batch.core.StepExecution;
import org.springframework.batch.core.partition.PartitionHandler;
import org.springframework.batch.core.partition.StepExecutionSplitter;
import org.springframework.util.StringUtils;
import org.springframework.yarn.am.container.ContainerRequestHint;
import org.springframework.yarn.batch.am.AbstractBatchAppmaster;

/**
 * Implementation of Spring Batch {@link PartitionHandler} which does
 * partitioning based on number of input files from HDFS.
 *
 * @author Janne Valkealahti
 *
 */
public class HdfsSplitBatchPartitionHandler extends AbstractBatchPartitionHandler {

    private static final Log log = LogFactory.getLog(HdfsSplitBatchPartitionHandler.class);

    /** Yarn configuration */
    private Configuration configuration;

    /**
     * Instantiates a new hdfs split batch partition handler.
     *
     * @param batchAppmaster the batch appmaster
     */
    public HdfsSplitBatchPartitionHandler(AbstractBatchAppmaster batchAppmaster) {
        this(batchAppmaster, null);
    }

    /**
     * Instantiates a new hdfs split batch partition handler.
     *
     * @param batchAppmaster the batch appmaster
     */
    public HdfsSplitBatchPartitionHandler(AbstractBatchAppmaster batchAppmaster, Configuration configuration) {
        super(batchAppmaster);
        this.configuration = configuration;
    }

    /**
     * Gets the Yarn configuration.
     *
     * @return the Yarn configuration
     */
    public Configuration getConfiguration() {
        return configuration;
    }

    /**
     * Sets the Yarn configuration.
     *
     * @param configuration the new Yarn configuration
     */
    public void setConfiguration(Configuration configuration) {
        this.configuration = configuration;
    }

    @Override
    protected Set<StepExecution> createStepExecutionSplits(StepExecutionSplitter stepSplitter,
            StepExecution stepExecution) throws Exception {

        String input = stepExecution.getJobParameters().getString("input");
        log.info("Input is " + input);

        FileSystem fs = FileSystem.get(configuration);
        Path path = new Path(input);
        FileStatus[] fileStatuses = fs.globStatus(path);

        Set<StepExecution> split = stepSplitter.split(stepExecution, fileStatuses.length);
        return split;
    }

    @Override
    protected Map<StepExecution, ContainerRequestHint> createResourceRequestData(Set<StepExecution> stepExecutions)
            throws Exception {
        Map<StepExecution, ContainerRequestHint> requests = new HashMap<StepExecution, ContainerRequestHint>();

        for (StepExecution execution : stepExecutions) {
            String fileName = execution.getExecutionContext().getString("fileName");
            long splitStart = execution.getExecutionContext().getLong("splitStart");
            long splitLength = execution.getExecutionContext().getLong("splitLength");

            log.debug("Creating request data for stepExecution=" + execution + " with fileName=" + fileName
                    + " splitStart=" + splitStart + " splitLength=" + splitLength);

            FileSystem fs = FileSystem.get(configuration);
            Path path = new Path(execution.getExecutionContext().getString("fileName"));

            HashSet<String> hostsSet = new HashSet<String>();

            BlockLocation[] fileBlockLocations = fs.getFileBlockLocations(path, splitStart, splitLength);
            for (BlockLocation blockLocation : fileBlockLocations) {
                for (String host : blockLocation.getHosts()) {
                    hostsSet.add(host);
                }
                log.debug("block: " + blockLocation + " topologypaths="
                        + StringUtils.arrayToCommaDelimitedString(blockLocation.getTopologyPaths()));
            }

            String[] hosts = hostsSet.toArray(new String[0]);
            String[] racks = new String[0];
            // hints only for hosts
            requests.put(execution, new ContainerRequestHint(execution, null, hosts, racks, null));
        }

        return requests;
    }

}