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我试图自定义批量加载map-reduce进入HBase,并遇到reducer问题。首先,我认为我没有很好地编写reducer,但是当在reducer中抛出运行时异常并看到代码正常工作时,我意识到reducer没有运行。 到目前为止,对于这个问题的一些常见问题,我没有看到任何问题;Hadoop mapreduce - reducer未运行
- 我的配置已经mapoutput和输出单独
- 我减速器和映射器已覆盖
- 我可迭代的,我减速器输入(可写,放),所以...
这里是我的代码:
驱动
public int run(String[] args) throws Exception {
int result=0;
String outputPath = args[1];
Configuration configuration = getConf();
configuration.set("data.seperator", DATA_SEPERATOR);
configuration.set("hbase.table.name",TABLE_NAME);
configuration.set("COLUMN_FAMILY_1",COLUMN_FAMILY_1);
Job job = new Job(configuration);
job.setJarByClass(HBaseBulkLoadDriver.class);
job.setJobName("Bulk Loading HBase Table::"+TABLE_NAME);
job.setInputFormatClass(TextInputFormat.class);
job.setMapOutputKeyClass(ImmutableBytesWritable.class);
job.setMapperClass(HBaseBulkLoadMapper.class);
job.setReducerClass(HBaseBulkLoadReducer.class);
job.setOutputKeyClass(ImmutableBytesWritable.class);
job.setOutputValueClass(Put.class);
FileInputFormat.addInputPaths(job, args[0]);
FileSystem.getLocal(getConf()).delete(new Path(outputPath), true);
FileOutputFormat.setOutputPath(job, new Path(outputPath));
job.setMapOutputValueClass(Put.class);
job.setNumReduceTasks(1);
HFileOutputFormat.configureIncrementalLoad(job, new HTable(configuration,TABLE_NAME));
job.waitForCompletion(true);
映射
public class HBaseBulkLoadMapper extends Mapper<LongWritable, Text, ImmutableBytesWritable, Put> {
private String hbaseTable;
private String dataSeperator;
private String columnFamily1;
private ImmutableBytesWritable hbaseTableName;
public void setup(Context context) {
Configuration configuration = context.getConfiguration();
hbaseTable = configuration.get("hbase.table.name");
dataSeperator = configuration.get("data.seperator");
columnFamily1 = configuration.get("COLUMN_FAMILY_1");
hbaseTableName = new ImmutableBytesWritable(Bytes.toBytes(hbaseTable));
}
@Override
public void map(LongWritable key, Text value, Context context) {
try {
String[] values = value.toString().split(dataSeperator);
String rowKey = values[0];
Put put = new Put(Bytes.toBytes(rowKey));
BUNCH OF ADDS;
context.write(new ImmutableBytesWritable(Bytes.toBytes(rowKey)), put);
} catch(Exception exception) {
exception.printStackTrace();
}
}
}
减速
public class HBaseBulkLoadReducer extends Reducer<ImmutableBytesWritable, Put, ImmutableBytesWritable, Put> {
@Override
protected void reduce(
ImmutableBytesWritable row,
Iterable<Put> puts,
Reducer<ImmutableBytesWritable, Put,
ImmutableBytesWritable, Put>.Context context)
throws java.io.IOException, InterruptedException
{
TreeMap<String,KeyValue> map = new TreeMap<String,KeyValue>();
int count =0;
Append nkv;
byte[] tmp= "".getBytes();
Put pp = new Put(tmp);
try{
for (Put p : puts) {
byte[] r = "".getBytes();
//KeyValue kv = new KeyValue(r);
if (count!=0){
r = p.getRow();
pp.add(new KeyValue(r));
//KeyValue k = map.get(row.toString());
//nkv = new Append(k.getRowArray());
//nkv=nkv.add(kv);
//map.put(row.toString(), k.clone());
//context.write(row,nkv);
//tmp=ArrayUtils.addAll(tmp,kv.getValueArray());
//map.put(row.toString(),new KeyValue(kv.getRowArray(),kv.getFamilyArray(),kv.getQualifierArray(),tmp));
count++;
throw new RuntimeException();
}
else{
r = p.getRow();
pp = new Put(row.toString().getBytes());
pp.add(new KeyValue(r));
//tmp=kv.clone().getValueArray();
//nkv = new Append(kv.getRowArray());
//map.put(row.toString(), kv.clone());
count++;
throw new RuntimeException();
}
}
context.write(row,pp);
}catch(Exception e) { e.printStackTrace();}
}
}
嗯,我知道减速机是有点混乱,但事实是,它的RuntimeException两个if和else子句,你可以看到和批量加载成功,所以我很确定减速机没有运转 - 我不知道为什么。所有三个文件都是maven打包在同一个目录下,FYI。
为什么你含蓄'抛出新的RuntimeException();'? –
他试图查看块是否执行......“但是当在reducer中抛出运行异常并看到代码正常工作时,我意识到reducer没有运行” – Tgsmith61591
我认为reducer应该基于'job .setNumReduceTasks(1)'但如果'Iterable puts'为空,那么reducer的for循环将不会被输入,并且这些异常将不会被抛出 –