用于使用Hadoop流的avro转换的python脚本

我有10 GB的输入文件，我正在尝试使用python hadoop流媒体将其转换为avro，作业已成功，但我无法使用avro阅读器读取输出

它给出的“utf8”编解码器无法解码13924位置的字节0xb4：无效的开始字节

这里的问题是我在hadoop流媒体中使用映射器输出的stdout，如果我在本地使用文件名和脚本，avro输出是可读的

有什么想法，怎么解决这个问题？我认为问题在于如何处理流媒体中的键/值

hadoop jar /opt/cloudera/parcels/CDH/lib/hadoop-0.20-mapreduce/contrib/streaming/hadoop-streaming.jar \
                      -input "xxx.txt" \
                      -mapper "/opt/anaconda/anaconda21/bin/python mapper.py x.avsc"  \
                      -reducer NONE \
                      -output "xxxxx" -file "mapper.py" \
                      -lazyOutput \
                      -file "x.avsc"

映射器脚本是

import sys
import re
import os
from avro import schema, datafile
import avro.io as io
import StringIO

schema_str = open("xxxxx.avsc", 'r').read()
SCHEMA = schema.parse(schema_str)
rec_writer = io.DatumWriter(SCHEMA)
df_writer  = datafile.DataFileWriter(sys.stdout, rec_writer, SCHEMA,)
header = []
for field in SCHEMA.fields:
        header.append(field.name)

for line in sys.stdin:
    fields = line.rstrip().split("\x01")
    data   = dict(zip(header, fields))
    try:
        df_writer.append(data)
    except Exception, e:
        print "failed with data: %s" % str(data)
        print str(e)
df_writer.close()

---

终于可以解决这个问题了。使用output format类，并将avro二进制转换保留为该类。在streaming mapper中，只需发出json记录

hadoop jar /opt/cloudera/parcels/CDH/lib/hadoop-0.20-mapreduce/contrib/streaming/hadoop-streaming.jar \
              -libjars avro-json-1.2.jar \
              -jobconf output.schema.url=hdfs:///x.avsc \
              -input "xxxxx" \
              -mapper "/opt/anaconda/anaconda21/bin/python mapper.py x.avsc"  \
              -reducer NONE \
              -output "/xxxxx"  \
              -outputformat com.cloudera.science.avro.streaming.AvroAsJSONOutputFormat \
              -lazyOutput \
              -file "mapper.py" \
              -file "x.avsc"

这是mapper.py

import sys
from avro import schema
import json

schema_str = open("xxxxx.avsc", 'r').read()
SCHEMA = schema.parse(schema_str)

header = []
for field in SCHEMA.fields:
    header.append(field.name)

for line in sys.stdin:
    fields = line.rstrip().split("\x01")
    data   = dict(zip(header, fields))
    try:
       print >> sys.stdout, json.dumps(data, encoding='ISO-8859-1')
    except Exception, e:
       print "failed with data: %s" % str(data)
       print str(e)