[HADOOP] 직렬화에서 Avro NullPointerException이있는 MRUnit

직렬화에서 Avro NullPointerException이있는 MRUnit

MRUnit을 사용하여 Hadoop .mapreduce Avro 작업을 테스트하려고합니다. 아래에서 볼 수 있듯이 NullPointerException을 받고 있습니다. 나는 pom과 소스 코드의 일부를 첨부했다. 어떤 도움을 주시면 감사하겠습니다.

감사

내가 얻는 오류는 다음과 같습니다.

java.lang.NullPointerException
at org.apache.hadoop.mrunit.internal.io.Serialization.copy(Serialization.java:73)
at org.apache.hadoop.mrunit.internal.io.Serialization.copy(Serialization.java:91)
at org.apache.hadoop.mrunit.internal.io.Serialization.copyWithConf(Serialization.java:104)
at org.apache.hadoop.mrunit.TestDriver.copy(TestDriver.java:608)
at org.apache.hadoop.mrunit.MapDriverBase.setInputKey(MapDriverBase.java:64)
at org.apache.hadoop.mrunit.MapDriverBase.setInput(MapDriverBase.java:104)
at org.apache.hadoop.mrunit.MapDriverBase.withInput(MapDriverBase.java:218)
at org.lab41.project.mapreduce.ParseMetadataAsTextIntoAvroTest.testMap(ParseMetadataAsTextIntoAvroTest.java:115)
.....

pom snippet :

<dependency>
    <groupId>org.apache.mrunit</groupId>
    <artifactId>mrunit</artifactId>
    <version>0.9.0-incubating</version>
    <classifier>hadoop2</classifier>
    <scope>test</scope>
</dependency>


<avro.version>1.7.4</avro.version>
<hadoop.version>2.0.0-mr1-cdh4.1.3</hadoop.version>

<dependency>
    <groupId>org.apache.avro</groupId>
    <artifactId>avro</artifactId>
    <version>${avro.version}</version>
</dependency>

<dependency>
    <groupId>org.apache.hadoop</groupId>
    <artifactId>hadoop-client</artifactId>
    <version>${hadoop.version}</version>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>org.apache.hadoop</groupId>
    <artifactId>hadoop-core</artifactId>
    <version>${hadoop.version}</version>
    <scope>provided</scope>
 </dependency>
 <dependency>
    <groupId>org.apache.avro</groupId>
    <artifactId>avro-mapred</artifactId>
    <version>${avro.version}</version>
    <classifier>hadoop2</classifier>
 </dependency>

다음은 시험 발췌입니다.

import static org.junit.Assert.*;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.text.ParseException;
import java.text.SimpleDateFormat;

import org.apache.avro.mapred.AvroKey;
import org.apache.avro.hadoop.io.AvroSerialization;
import org.apache.avro.mapred.AvroValue;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mrunit.mapreduce.MapDriver;
import org.apache.hadoop.mrunit.types.Pair;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import org.lab41.project.domain.DataRecord;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ParseMetadataAsTextIntoAvroTest {

    Logger logger = LoggerFactory
            .getLogger(ParseMetadataAsTextIntoAvroTest.class);
    private MapDriver<LongWritable, Text, AvroKey<Long>, AvroValue<DataRecord>> mapDriver;

    @BeforeClass
    public static void setUpClass() {
    }

    @AfterClass
    public static void tearDownClass() {
    }

    @Before
    public void setUp() throws IOException {
        ParseMetadataAsTextIntoAvroMapper mapper = new ParseMetadataAsTextIntoAvroMapper();

        mapDriver = new MapDriver<LongWritable, Text, AvroKey<Long>, AvroValue<DataRecord>>();
        mapDriver.setMapper(mapper);
        mapDriver.getConfiguration().setStrings("io.serializations", new String[]{  
            AvroSerialization.class.getName()
        });
    }

    @Test
    public void testMap() throws ParseException, IOException {
        Text testInputText = new Text(test0);

        DataRecord record = new DataRecord();
       ….

        AvroKey<Long> expectedPivot = new AvroKey<Long>(1L);
        AvroValue<DataRecord> expectedRecord = new AvroValue<DataRecord>(record);

        mapDriver.withInput(new Pair<LongWritable, Text>(new LongWritable(1), testInputText));
        mapDriver.withOutput(new Pair<AvroKey<Long>, AvroValue<DataRecord>>(expectedPivot, expectedRecord));
        mapDriver.runTest();

    }
}

해결법

1. ==============================

   1.이것을 작동 시키려면 AvroSerializatio를 기본 serailization에 추가하십시오. 또한 AvroSerializationn을 구성해야합니다.

   이것을 작동 시키려면 AvroSerializatio를 기본 serailization에 추가하십시오. 또한 AvroSerializationn을 구성해야합니다.

    @Before
   public void setUp() throws IOException {
       ParseMetadataAsTextIntoAvroMapper mapper = new ParseMetadataAsTextIntoAvroMapper();
       mapDriver = new MapDriver<LongWritable, Text, AvroKey<Long>, AvroValue<NetworkRecord>>();
       mapDriver.setMapper(mapper);
   
       //Copy over the default io.serializations. If you don't do this then you will 
       //not be able to deserialize the inputs to the mapper
       String[] strings = mapDriver.getConfiguration().getStrings("io.serializations");
       String[] newStrings = new String[strings.length +1];
       System.arraycopy( strings, 0, newStrings, 0, strings.length );
       newStrings[newStrings.length-1] = AvroSerialization.class.getName();
   
       //Now you have to configure AvroSerialization by sepecifying the key
       //writer Schema and the value writer schema.
       mapDriver.getConfiguration().setStrings("io.serializations", newStrings);
       mapDriver.getConfiguration().setStrings("avro.serialization.key.writer.schema", Schema.create(Schema.Type.LONG).toString(true));
       mapDriver.getConfiguration().setStrings("avro.serialization.value.writer.schema", NetworkRecord.SCHEMA$.toString(true));
   }
   

2. ==============================

   2.이것은 또한 더 짧고 명확한 코드의 장점으로 문제를 해결합니다.

   이것은 또한 더 짧고 명확한 코드의 장점으로 문제를 해결합니다.

           MapDriver driver = MapDriver.newMapDriver(your mapper);
   
           Configuration conf = driver.getConfiguration();
           AvroSerialization.addToConfiguration(conf);
           AvroSerialization.setKeyWriterSchema(conf, your schema);
           AvroSerialization.setKeyReaderSchema(conf, your schema);
           Job job = new Job(conf);
           job.set... your job settings;
           AvroJob.set... your avro job settings;
   

   mrunit의 버그 일 수 있으며, io.serializations 권한을 설정하지 마십시오. 대신 job.setInputFormatClass (AvroKeyInputFormat.class)에 의해 설정되어 있어야합니다.

3. ==============================

   3.기본 직렬화에 AvroSerialization을 추가하고 AvroSerialization을 구성해야합니다.

   기본 직렬화에 AvroSerialization을 추가하고 AvroSerialization을 구성해야합니다.

   @Before
   public void setUp() throws IOException {
       ParseMetadataAsTextIntoAvroMapper mapper = new ParseMetadataAsTextIntoAvroMapper();
       mapDriver = new MapDriver<LongWritable, Text, AvroKey<Long>, AvroValue<NetworkRecord>>();
       mapDriver.setMapper(mapper);
       Configuration configuration = mapDriver.getConfiguration();
   
       // Add AvroSerialization to the configuration
       // (copy over the default serializations for deserializing the mapper inputs)
       String[] serializations = configuration.getStrings(CommonConfigurationKeysPublic.IO_SERIALIZATIONS_KEY);
       String[] newSerializations = Arrays.copyOf(serializations, serializations.length + 1);
       newSerializations[serializations.length] = AvroSerialization.class.getName();
       configuration.setStrings(CommonConfigurationKeysPublic.IO_SERIALIZATIONS_KEY, newSerializations);
   
       //Configure AvroSerialization by specifying the key writer and value writer schemas
       AvroSerialization.setKeyWriterSchema(configuration, Schema.create(Schema.Type.LONG));
       AvroSerialization.setValueWriterSchema(configuration, NetworkRecord.SCHEMA$)
   }
   

4. ==============================

   4.여기에 답변 : https://issues.apache.org/jira/browse/MRUNIT-181 구체적으로 : https://cwiki.apache.org/confluence/display/MRUNIT/MRUnit+with+Avro

   여기에 답변 : https://issues.apache.org/jira/browse/MRUNIT-181 구체적으로 : https://cwiki.apache.org/confluence/display/MRUNIT/MRUnit+with+Avro

from https://stackoverflow.com/questions/15230482/mrunit-with-avro-nullpointerexception-in-serialization by cc-by-sa and MIT license