我正在使用:
hadoop客户端2.2.0
MR1.0.0单元
avro 1.7.6版本
avro MR1.7.6单元
... 整个过程都在使用maven进行构建和测试。
我得到了一个nullpointerexception,直到我按照mrunit的说明在序列化中使用avro nullpointerexception。
现在我得到一个示例化异常:
Running mypackage.MyTest
log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
2014-03-23 20:49:21.463 java[27994:1003] Unable to load realm info from SCDynamicStore
Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.945 sec <<< FAILURE!
process(mypackage.MyTest) Time elapsed: 0.909 sec <<< ERROR!
java.lang.RuntimeException: java.lang.InstantiationException
at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:131)
at org.apache.hadoop.io.serializer.SerializationFactory.add(SerializationFactory.java:72)
at org.apache.hadoop.io.serializer.SerializationFactory.<init>(SerializationFactory.java:63)
at org.apache.hadoop.mrunit.internal.io.Serialization.<init>(Serialization.java:37)
at org.apache.hadoop.mrunit.TestDriver.getSerialization(TestDriver.java:464)
at org.apache.hadoop.mrunit.TestDriver.copy(TestDriver.java:608)
at org.apache.hadoop.mrunit.TestDriver.copyPair(TestDriver.java:612)
at org.apache.hadoop.mrunit.MapDriverBase.addInput(MapDriverBase.java:118)
at org.apache.hadoop.mrunit.MapDriverBase.withInput(MapDriverBase.java:207)
at mypackage.MyTest.process(MyTest.java:92)
...
avro型号如下:
{
"namespace": "model",
"type": "record",
"name": "Blob",
"fields": [
{ "name": "value", "type": "string" }
]
}
Map器如下所示:
public class MyMapper
extends Mapper<AvroKey<Blob>, NullWritable, LongWritable, NullWritable>
{
@Override
public void map(AvroKey<Blob> key, NullWritable value, Context context)
throws IOException, InterruptedException {
context.write(new LongWritable(0), NullWritable.get());
}
}
失败的测试(我目前唯一的测试)如下所示:
@Test
public void process() throws IOException {
mapper = new MyMapper();
job = Job.getInstance();
mapDriver = MapDriver.newMapDriver(mapper);
Configuration configuration = mapDriver.getConfiguration();
//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[] serializations = configuration.getStrings("io.serializations");
serializations = Arrays.copyOf(serializations, serializations.length + 1);
serializations[serializations.length-1] = AvroSerialization.class.getName();
configuration.setStrings("io.serializations", serializations);
//Configure AvroSerialization by specifying the key writer and value writer schemas
configuration.setStrings("avro.serialization.key.writer.schema", Schema.create(Schema.Type.LONG).toString(true));
configuration.setStrings("avro.serialization.value.writer.schema", Schema.create(Schema.Type.NULL).toString(true));
job.setMapperClass(MyMapper.class);
job.setInputFormatClass(AvroKeyInputFormat.class);
AvroJob.setInputKeySchema(job, Blob.SCHEMA$);
job.setOutputKeyClass(LongWritable.class);
input = Blob.newBuilder()
.setValue("abc")
.build();
mapDriver
.withInput(new AvroKey<Blob>(input), NullWritable.get())
.withOutput(new LongWritable(0), NullWritable.get())
.runTest();
}
我对avro和mrunit都很陌生,所以我仍在努力完全理解它们之间的工作原理。在单元测试输出中,我看到了关于log4j的警告,并且不确定这不是问题的一部分(尽管我对此表示怀疑)。
1条答案
按热度按时间fhg3lkii1#
试试这个;虽然这是reflectionutil的错误,但是外部框架是关于序列化的,您没有实现可写的。所以我认为这可能是关于avro序列化设置不正确。