Question

为了尝试使用Amazon EMR解决performance issues，我尝试使用s3distcp将文件从S3复制到我的EMR群集以进行本地处理。作为第一个测试，我使用--groupBy选项从单个目录复制一天的数据，即2160个文件，将它们折叠成一个（或几个）文件。

这项工作似乎运行得很好，向我显示地图/减少进度到100％，但此时进程挂起并且永远不会回来。我怎样才能弄清楚发生了什么？

源文件是存储在S3中的GZip文本文件，每个文件大约30kb。这是一个vanilla Amazon EMR集群，我正在从主节点的shell运行s3distcp。

hadoop@ip-xxx:~$ hadoop jar /home/hadoop/lib/emr-s3distcp-1.0.jar --src s3n://xxx/click/20140520 --dest hdfs:////data/click/20140520 --groupBy ".*(20140520).*" --outputCodec lzo
14/05/21 20:06:32 INFO s3distcp.S3DistCp: Running with args: [Ljava.lang.String;@26f3bbad
14/05/21 20:06:35 INFO s3distcp.S3DistCp: Using output path 'hdfs:/tmp/9f423c59-ec3a-465e-8632-ae449d45411a/output'
14/05/21 20:06:35 INFO s3distcp.S3DistCp: GET http://169.254.169.254/latest/meta-data/placement/availability-zone result: us-west-2b
14/05/21 20:06:35 INFO s3distcp.S3DistCp: Created AmazonS3Client with conf KeyId AKIAJ5KT6QSV666K6KHA
14/05/21 20:06:37 INFO s3distcp.FileInfoListing: Opening new file: hdfs:/tmp/9f423c59-ec3a-465e-8632-ae449d45411a/files/1
14/05/21 20:06:38 INFO s3distcp.S3DistCp: Created 1 files to copy 2160 files
14/05/21 20:06:38 INFO mapred.JobClient: Default number of map tasks: null
14/05/21 20:06:38 INFO mapred.JobClient: Setting default number of map tasks based on cluster size to : 72
14/05/21 20:06:38 INFO mapred.JobClient: Default number of reduce tasks: 3
14/05/21 20:06:39 INFO security.ShellBasedUnixGroupsMapping: add hadoop to shell userGroupsCache
14/05/21 20:06:39 INFO mapred.JobClient: Setting group to hadoop
14/05/21 20:06:39 INFO mapred.FileInputFormat: Total input paths to process : 1
14/05/21 20:06:39 INFO mapred.JobClient: Running job: job_201405211343_0031
14/05/21 20:06:40 INFO mapred.JobClient:  map 0% reduce 0%
14/05/21 20:06:53 INFO mapred.JobClient:  map 1% reduce 0%
14/05/21 20:06:56 INFO mapred.JobClient:  map 4% reduce 0%
14/05/21 20:06:59 INFO mapred.JobClient:  map 36% reduce 0%
14/05/21 20:07:00 INFO mapred.JobClient:  map 44% reduce 0%
14/05/21 20:07:02 INFO mapred.JobClient:  map 54% reduce 0%
14/05/21 20:07:05 INFO mapred.JobClient:  map 86% reduce 0%
14/05/21 20:07:06 INFO mapred.JobClient:  map 94% reduce 0%
14/05/21 20:07:08 INFO mapred.JobClient:  map 100% reduce 10%
14/05/21 20:07:11 INFO mapred.JobClient:  map 100% reduce 19%
14/05/21 20:07:14 INFO mapred.JobClient:  map 100% reduce 27%
14/05/21 20:07:17 INFO mapred.JobClient:  map 100% reduce 29%
14/05/21 20:07:20 INFO mapred.JobClient:  map 100% reduce 100%
[hangs here]

这份工作显示为：

hadoop@xxx:~$ hadoop job -list
1 job currently running
JobId   State   StartTime       UserName        Priority        SchedulingInfo
job_201405211343_0031   1       1400702799339   hadoop  NORMAL  NA

并且目标HDFS目录中没有任何内容：

hadoop@xxx:~$ hadoop dfs -ls /data/click/

有什么想法吗？

Answer 1

hadoop @ ip-xxx：〜$ hadoop jar /home/hadoop/lib/emr-s3distcp-1.0.jar --src s3n：// xxx / click / 20140520 ** / ** - hdfs：/ /// data / click / 20140520 ** / ** --groupBy＆＃34;。（20140520）。＆＃34; --outputCodec lzo

我遇到了类似的问题。我只需要在目录的末尾添加一个额外的斜杠。因此，它完成了，并且显示了统计数据，上限为100％

Answer 2

使用s3：//而不是s3n。

hadoop jar /home/hadoop/lib/emr-s3distcp-1.0.jar --src s3：// xxx / click / 20140520 --dest hdfs：//// data / click / 20140520 --groupBy＆＃ 34; （20140520）＆＃34。 --outputCodec lzo

显示100％后s3distcp挂起

2 个答案: