org.apache.hadoop.hive.ql.exec.tez.HivePreWarmProcessor.java Source code

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Here is the source code for org.apache.hadoop.hive.ql.exec.tez.HivePreWarmProcessor.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.hadoop.hive.ql.exec.tez;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.hive.common.JavaUtils;
import org.apache.hadoop.io.ReadaheadPool;
import org.apache.hadoop.hive.shims.ShimLoader;
import org.apache.tez.common.TezUtils;
import org.apache.tez.dag.api.UserPayload;
import org.apache.tez.runtime.api.AbstractLogicalIOProcessor;
import org.apache.tez.runtime.api.Event;
import org.apache.tez.runtime.api.LogicalInput;
import org.apache.tez.runtime.api.LogicalOutput;
import org.apache.tez.runtime.api.ProcessorContext;

import java.net.URL;
import java.net.JarURLConnection;
import java.util.Enumeration;
import java.util.List;
import java.util.Map;
import java.util.jar.JarFile;
import java.util.jar.JarEntry;

import javax.crypto.Mac;

/**
 * A simple sleep processor implementation that sleeps for the configured
 * time in milliseconds.
 *
 * @see Config for configuring the HivePreWarmProcessor
 */
public class HivePreWarmProcessor extends AbstractLogicalIOProcessor {

    private static boolean prewarmed = false;

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

    private Configuration conf;

    public HivePreWarmProcessor(ProcessorContext context) {
        super(context);
    }

    @Override
    public void initialize() throws Exception {
        UserPayload userPayload = getContext().getUserPayload();
        this.conf = TezUtils.createConfFromUserPayload(userPayload);
    }

    @Override
    public void run(Map<String, LogicalInput> inputs, Map<String, LogicalOutput> outputs) throws Exception {
        if (prewarmed) {
            /* container reuse */
            return;
        }
        for (LogicalInput input : inputs.values()) {
            input.start();
        }
        for (LogicalOutput output : outputs.values()) {
            output.start();
        }
        /* these are things that goes through singleton initialization on most queries */
        FileSystem fs = FileSystem.get(conf);
        Mac mac = Mac.getInstance("HmacSHA1");
        ReadaheadPool rpool = ReadaheadPool.getInstance();
        ShimLoader.getHadoopShims();

        URL hiveurl = new URL("jar:" + DagUtils.getInstance().getExecJarPathLocal() + "!/");
        JarURLConnection hiveconn = (JarURLConnection) hiveurl.openConnection();
        JarFile hivejar = hiveconn.getJarFile();
        try {
            Enumeration<JarEntry> classes = hivejar.entries();
            while (classes.hasMoreElements()) {
                JarEntry je = classes.nextElement();
                if (je.getName().endsWith(".class")) {
                    String klass = je.getName().replace(".class", "").replaceAll("/", "\\.");
                    if (klass.indexOf("ql.exec") != -1 || klass.indexOf("ql.io") != -1) {
                        /* several hive classes depend on the metastore APIs, which is not included
                         * in hive-exec.jar. These are the relatively safe ones - operators & io classes.
                         */
                        if (klass.indexOf("vector") != -1 || klass.indexOf("Operator") != -1) {
                            JavaUtils.loadClass(klass);
                        }
                    }
                }
            }
        } finally {
            hivejar.close();
        }
        prewarmed = true;
    }

    @Override
    public void handleEvents(List<Event> processorEvents) {
        // Nothing to do
    }

    @Override
    public void close() throws Exception {
        // Nothing to cleanup
    }
}