Hadoop 流作业在 Python 中失败(不成功)
问题描述
我正在尝试使用 Python 脚本在 Hadoop Streaming 上运行 Map-Reduce 作业,并遇到与 Hadoop Streaming Job failed error in python 但这些解决方案对我不起作用.
I'm trying to run a Map-Reduce job on Hadoop Streaming with Python scripts and getting the same errors as Hadoop Streaming Job failed error in python but those solutions didn't work for me.
当我运行cat sample.txt | ./p1mapper.py | sort | ./p1reducer.py"时,我的脚本运行良好
My scripts work fine when I run "cat sample.txt | ./p1mapper.py | sort | ./p1reducer.py"
但是当我运行以下命令时:
But when I run the following:
./bin/hadoop jar contrib/streaming/hadoop-0.20.2-streaming.jar
-input "p1input/*"
-output p1output
-mapper "python p1mapper.py"
-reducer "python p1reducer.py"
-file /Users/Tish/Desktop/HW1/p1mapper.py
-file /Users/Tish/Desktop/HW1/p1reducer.py
(注意:即使我删除python"或为-mapper和-reducer输入完整路径名,结果也是一样的)
(NB: Even if I remove the "python" or type the full pathname for -mapper and -reducer, the result is the same)
这是我得到的输出:
packageJobJar: [/Users/Tish/Desktop/HW1/p1mapper.py, /Users/Tish/Desktop/CS246/HW1/p1reducer.py, /Users/Tish/Documents/workspace/hadoop-0.20.2/tmp/hadoop-unjar4363616744311424878/] [] /var/folders/Mk/MkDxFxURFZmLg+gkCGdO9U+++TM/-Tmp-/streamjob3714058030803466665.jar tmpDir=null
11/01/18 03:02:52 INFO mapred.FileInputFormat: Total input paths to process : 1
11/01/18 03:02:52 INFO streaming.StreamJob: getLocalDirs(): [tmp/mapred/local]
11/01/18 03:02:52 INFO streaming.StreamJob: Running job: job_201101180237_0005
11/01/18 03:02:52 INFO streaming.StreamJob: To kill this job, run:
11/01/18 03:02:52 INFO streaming.StreamJob: /Users/Tish/Documents/workspace/hadoop-0.20.2/bin/../bin/hadoop job -Dmapred.job.tracker=localhost:54311 -kill job_201101180237_0005
11/01/18 03:02:52 INFO streaming.StreamJob: Tracking URL: http://www.glassdoor.com:50030/jobdetails.jsp?jobid=job_201101180237_0005
11/01/18 03:02:53 INFO streaming.StreamJob: map 0% reduce 0%
11/01/18 03:03:05 INFO streaming.StreamJob: map 100% reduce 0%
11/01/18 03:03:44 INFO streaming.StreamJob: map 50% reduce 0%
11/01/18 03:03:47 INFO streaming.StreamJob: map 100% reduce 100%
11/01/18 03:03:47 INFO streaming.StreamJob: To kill this job, run:
11/01/18 03:03:47 INFO streaming.StreamJob: /Users/Tish/Documents/workspace/hadoop-0.20.2/bin/../bin/hadoop job -Dmapred.job.tracker=localhost:54311 -kill job_201101180237_0005
11/01/18 03:03:47 INFO streaming.StreamJob: Tracking URL: http://www.glassdoor.com:50030/jobdetails.jsp?jobid=job_201101180237_0005
11/01/18 03:03:47 ERROR streaming.StreamJob: Job not Successful!
11/01/18 03:03:47 INFO streaming.StreamJob: killJob...
Streaming Job Failed!
对于每个失败/终止的任务尝试:
For each Failed/Killed Task Attempt:
Map output lost, rescheduling: getMapOutput(attempt_201101181225_0001_m_000000_0,0) failed :
org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find taskTracker/jobcache/job_201101181225_0001/attempt_201101181225_0001_m_000000_0/output/file.out.index in any of the configured local directories
at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathToRead(LocalDirAllocator.java:389)
at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathToRead(LocalDirAllocator.java:138)
at org.apache.hadoop.mapred.TaskTracker$MapOutputServlet.doGet(TaskTracker.java:2887)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:502)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:363)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:417)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:324)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:534)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:864)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:533)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:207)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:403)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:522)
这是我的 Python 脚本:p1mapper.py
Here are my Python scripts: p1mapper.py
#!/usr/bin/env python
import sys
import re
SEQ_LEN = 4
eos = re.compile('(?<=[a-zA-Z]).') # period preceded by an alphabet
ignore = re.compile('[Wd]')
for line in sys.stdin:
array = re.split(eos, line)
for sent in array:
sent = ignore.sub('', sent)
sent = sent.lower()
if len(sent) >= SEQ_LEN:
for i in range(len(sent)-SEQ_LEN + 1):
print '%s 1' % sent[i:i+SEQ_LEN]
p1reducer.py
p1reducer.py
#!/usr/bin/env python
from operator import itemgetter
import sys
word2count = {}
for line in sys.stdin:
word, count = line.split(' ', 1)
try:
count = int(count)
word2count[word] = word2count.get(word, 0) + count
except ValueError: # count was not a number
pass
# sort
sorted_word2count = sorted(word2count.items(), key=itemgetter(1), reverse=True)
# write the top 3 sequences
for word, count in sorted_word2count[0:3]:
print '%s %s'% (word, count)
非常感谢任何帮助,谢谢!
Would really appreciate any help, thanks!
更新:
hdfs-site.xml:
hdfs-site.xml:
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>
mapred-site.xml:
mapred-site.xml:
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>mapred.job.tracker</name>
<value>localhost:54311</value>
</property>
</configuration>
解决方案
你缺少很多配置,你需要定义目录等.见这里:
You are missing a lot of configurations and you need to define directories and such. See here:
http://wiki.apache.org/hadoop/QuickStart
分布式操作和上面描述的伪分布式操作一样,除了:
Distributed operation is just like the pseudo-distributed operation described above, except:
- 在 conf/hadoop-site.xml 的 fs.default.name 和 mapred.job.tracker 的值中指定主服务器的主机名或 IP 地址.这些被指定为主机:端口对.
- 在 conf/hadoop-site.xml 中指定 dfs.name.dir 和 dfs.data.dir 的目录.它们分别用于保存主节点和从节点上的分布式文件系统数据.请注意,dfs.data.dir 可能包含以空格或逗号分隔的目录名称列表,以便数据可以存储在多个设备上.
- 在 conf/hadoop-site.xml 中指定 mapred.local.dir.这决定了临时 MapReduce 数据的写入位置.它也可以是目录列表.
- 在 conf/mapred-default.xml 中指定 mapred.map.tasks 和 mapred.reduce.tasks.根据经验,mapred.map.tasks 使用 10 倍的从处理器数量,mapred.reduce.tasks 使用 2 倍的从处理器数量.
- 在您的 conf/slaves 文件中列出所有从属主机名或 IP 地址,每行一个,并确保 jobtracker 在您的/etc/hosts 文件中指向您的 jobtracker 节点
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