Question

我想将MongoDB与Hadoop结合使用。我找到的是Mongo-Hadoop Connector。但是我找不到关于这个例子的完整文档。

mongo-hadoop/examples/sensors，build，run_job.sh，src，testdata_generator.js分别有四个文件。我使用testdata_generator.js将数据导入MongoDB，dbs为demo。当我尝试运行run_job.sh时，有一个例外：

MongoDB shell version: 2.6.1
connecting to: demo
false
Exception in thread "main" java.lang.ClassNotFoundException: -D
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:249)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:205)

run_job.sh

#!/bin/sh


mongo demo --eval "db.logs_aggregate.drop()"
#Set your HADOOP_HOME directory here.
#export HADOOP_HOME="/Users/mike/hadoop/hadoop-2.0.0-cdh4.3.0" 
export HADOOP_HOME="/home/hduser/hadoop"

#FIRST PASS - map all the devices into an output collection
declare -a job1_args
job1_args=("jar" "`pwd`/build/libs/sensors-1.2.1-SNAPSHOT-hadoop_2.2.jar")
#job1_args=(${job1_args[@]} "com.mongodb.hadoop.examples.sensors.Devices")
job1_args=(${job1_args[@]} "-D" "mongo.job.input.format=com.mongodb.hadoop.MongoInputFormat")
job1_args=(${job1_args[@]} "-D" "mongo.input.uri=mongodb://localhost:27017/demo.devices")
job1_args=(${job1_args[@]} "-D" "mongo.job.mapper=com.mongodb.hadoop.examples.sensors.DeviceMapper")
job1_args=(${job1_args[@]} "-D" "mongo.job.reducer=com.mongodb.hadoop.examples.sensors.DeviceReducer")

job1_args=(${job1_args[@]} "-D" "mongo.job.output.key=org.apache.hadoop.io.Text")
job1_args=(${job1_args[@]} "-D" "mongo.job.output.value=org.apache.hadoop.io.Text")

job1_args=(${job1_args[@]} "-D" "mongo.output.uri=mongodb://localhost:27017/demo.logs_aggregate")
job1_args=(${job1_args[@]} "-D" "mongo.job.output.format=com.mongodb.hadoop.MongoOutputFormat")
$HADOOP_HOME/bin/hadoop "${job1_args[@]}" "$1"

我可以在我的计算机上运行基本的Map / Reduce示例，但这个问题困扰了我很多天......

新编辑的内容：

我可以通过以下步骤运行此示例：

汇编Devices.java，DeviceMapper.java，DeviceReducer.java，和SensorDataGenerator.java到.class;该命令为 javac -classpath [library files] -d [folders] Devices.java DeviceMapper.java DeviceReducer.java SensorDataGenerator.java
将.class文件编译为.jar;该命令为 jar -cvf [jar file name] -C [path]
执行hadoop;该命令是hadoop jar [jar file name] [class name]

但我不知道为什么我无法成功执行run_job.sh。

Devices.java，这是这个例子中的主要java文件：

public class Devices extends MongoTool {

    public Devices() throws UnknownHostException {
        Configuration conf = new Configuration();
        MongoConfig config = new MongoConfig(conf);
        setConf(conf);

        config.setInputFormat(MongoInputFormat.class);
        config.setInputURI("mongodb://localhost:27017/demo.devices");
        config.setOutputFormat(MongoOutputFormat.class);
        config.setOutputURI("mongodb://localhost:27017/demo.logs_aggregate");

        config.setMapper(DeviceMapper.class);
        config.setReducer(DeviceReducer.class);
        config.setMapperOutputKey(Text.class);
        config.setMapperOutputValue(Text.class);
        config.setOutputKey(IntWritable.class);
        config.setOutputValue(BSONWritable.class);

        new SensorDataGenerator().run();
    }
    public static void main(final String[] pArgs) throws Exception {
        System.exit(ToolRunner.run(new Devices(), pArgs));
    }
}

Answer 1

使用gradle运行它。那些bash脚本有点过时，应该删除：

./ gradlew sensorData

如何执行Mongo-Hadoop Connector的传感器日志示例？

1 个答案: