到目前为止还没有看到我的特定问题的解决方案。至少它不工作。它让我非常疯狂。这个特别的组合在谷歌空间似乎没有很多。我的错误发生在工作从我所知道的映射器中进入映射器时。这个工作的输入是avro模式的输出,虽然我尝试了未压缩,但是用deflate压缩。找到的接口org.apache.hadoop.mapreduce.TaskAttemptContext
的Avro:1.7.7 的Hadoop:2.4.1
我得到这个错误,我不知道为什么。这是我的工作,mapper和减少。当映射进来的错误是发生
样品未压缩的Avro输入文件(StockReport.SCHEMA这样定义)
{"day": 3, "month": 2, "year": 1986, "stocks": [{"symbol": "AAME", "timestamp": 507833213000, "dividend": 10.59}]}
工作
@Override
public int run(String[] strings) throws Exception {
Job job = Job.getInstance();
job.setJobName("GenerateGraphsJob");
job.setJarByClass(GenerateGraphsJob.class);
configureJob(job);
int resultCode = job.waitForCompletion(true) ? 0 : 1;
return resultCode;
}
private void configureJob(Job job) throws IOException {
try {
Configuration config = getConf();
Path inputPath = ConfigHelper.getChartInputPath(config);
Path outputPath = ConfigHelper.getChartOutputPath(config);
job.setInputFormatClass(AvroKeyInputFormat.class);
AvroKeyInputFormat.addInputPath(job, inputPath);
AvroJob.setInputKeySchema(job, StockReport.SCHEMA$);
job.setMapperClass(StockAverageMapper.class);
job.setCombinerClass(StockAverageCombiner.class);
job.setReducerClass(StockAverageReducer.class);
FileOutputFormat.setOutputPath(job, outputPath);
} catch (IOException | ClassCastException e) {
LOG.error("An job error has occurred.", e);
}
}
映射:
public class StockAverageMapper extends
Mapper<AvroKey<StockReport>, NullWritable, StockYearSymbolKey, StockReport> {
private static Logger LOG = LoggerFactory.getLogger(StockAverageMapper.class);
private final StockReport stockReport = new StockReport();
private final StockYearSymbolKey stockKey = new StockYearSymbolKey();
@Override
protected void map(AvroKey<StockReport> inKey, NullWritable ignore, Context context)
throws IOException, InterruptedException {
try {
StockReport inKeyDatum = inKey.datum();
for (Stock stock : inKeyDatum.getStocks()) {
updateKey(inKeyDatum, stock);
updateValue(inKeyDatum, stock);
context.write(stockKey, stockReport);
}
} catch (Exception ex) {
LOG.debug(ex.toString());
}
}
地图输出键的模式:
{
"namespace": "avro.model",
"type": "record",
"name": "StockYearSymbolKey",
"fields": [
{
"name": "year",
"type": "int"
},
{
"name": "symbol",
"type": "string"
}
]
}
堆栈跟踪:
java.lang.Exception: java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected
at org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:462)
at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:522)
Caused by: java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected
at org.apache.avro.mapreduce.AvroKeyInputFormat.createRecordReader(AvroKeyInputFormat.java:47)
at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.<init>(MapTask.java:492)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:735)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:340)
at org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:243)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
编辑:这不是问题,但我的工作,以减少这个数据我可以从创建的JFreeChart输出。没有通过映射器,所以不应该关联。
我会试试看。这些编译的Avro类与我的其他工作一起工作。它只是在这个使用共享库的工作中。我的pom有1.7.7 avro-mapred,avro-tools和avro。我用一个名为avro-tools-1.7.7.jar的jar手动编译avro模式。 – Rig 2015-04-05 02:20:24
你钉了它。谢谢。 – Rig 2015-04-05 14:09:43