alluxio.hadoop.ConfUtils.java Source code

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Here is the source code for alluxio.hadoop.ConfUtils.java

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/*
 * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
 * (the "License"). You may not use this work except in compliance with the License, which is
 * available at www.apache.org/licenses/LICENSE-2.0
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied, as more fully set forth in the License.
 *
 * See the NOTICE file distributed with this work for information regarding copyright ownership.
 */

package alluxio.hadoop;

import alluxio.Configuration;
import alluxio.Constants;
import alluxio.PropertyKey;

import org.apache.hadoop.io.DefaultStringifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.Map;
import java.util.Properties;

import javax.annotation.concurrent.ThreadSafe;

/**
 * Utility class for {@link Configuration}.
 */
@ThreadSafe
public final class ConfUtils {
    private static final Logger LOG = LoggerFactory.getLogger(Constants.LOGGER_TYPE);

    private ConfUtils() {
    } // Prevent instantiation.

    /**
     * Stores the Alluxio {@link Configuration} to the target
     * Hadoop {@link org.apache.hadoop.conf.Configuration} object.
     *
     * @param target the {@link org.apache.hadoop.conf.Configuration} target
     */
    public static void storeToHadoopConfiguration(org.apache.hadoop.conf.Configuration target) {
        // Need to set io.serializations key to prevent NPE when trying to get SerializationFactory.
        target.set("io.serializations", "org.apache.hadoop.io.serializer.JavaSerialization,"
                + "org.apache.hadoop.io.serializer.WritableSerialization");
        Map<String, String> confProperties = Configuration.toMap();
        try {
            DefaultStringifier.store(target, confProperties, PropertyKey.SITE_CONF_DIR.toString());
        } catch (IOException ex) {
            LOG.error("Unable to store Alluxio configuration in Hadoop configuration", ex);
            throw new RuntimeException(ex);
        }
    }

    /**
     * Merges Hadoop {@link org.apache.hadoop.conf.Configuration} into the Alluxio configuration.
     *
     * @param source the {@link org.apache.hadoop.conf.Configuration} to merge
     */
    public static void mergeHadoopConfiguration(org.apache.hadoop.conf.Configuration source) {
        // Load Alluxio configuration if any and merge to the one in Alluxio file system
        // Push Alluxio configuration to the Job configuration
        Properties alluxioConfProperties = new Properties();
        // Load any Alluxio configuration parameters existing in the Hadoop configuration.
        for (Map.Entry<String, String> entry : source) {
            String propertyName = entry.getKey();
            if (PropertyKey.isValid(propertyName)) {
                alluxioConfProperties.put(propertyName, entry.getValue());
            }
        }
        LOG.info("Loading Alluxio properties from Hadoop configuration: {}", alluxioConfProperties);
        // Merge the relevant Hadoop configuration into Alluxio's configuration.
        // TODO(jiri): support multiple client configurations (ALLUXIO-2034)
        Configuration.merge(alluxioConfProperties);
    }
}