pig：如何将hdfs ls的输出加载到别名中？

lvmkulzt 于 2021-06-04 发布在 Hadoop

关注(0)|答案(2)|浏览(314)

我试图查看hdfs中的文件，并评估哪些文件比某个日期早。我想做一个 hdfs ls 把它的输出传给一头Pig LOAD 命令。
如何使用pig加载文件夹中的每个文件@donaldminer包含一个输出文件名的shell脚本；我借这个来传递一个文件名列表。但是，我不想加载文件的内容，我只想加载 ls 命令并将文件名视为文本。
这是myfirstscript.pig：

test = LOAD '$files' as (moddate:chararray, modtime:chararray, filename:chararray);

illustrate test;

我称之为：

pig -p files="`./filesysoutput.sh`" myfirstscript.pig

其中filesysoutput.sh包含：

hadoop fs -ls -R /hbase/imagestore | grep '\-rw' | awk 'BEGIN { FS = ",[ \t]*|[ \t]+" } {print $6, $7, $8}' | tr '\n' ','

这会产生如下输出：

2012-07-27 17:56 /hbase/imagestore/.tableinfo.0000000001,2012-04-23 19:27 /hbase/imagestore/08e36507d743367e1de57c359360b64c/.regioninfo,2012-05-10 12:13 /hbase/imagestore/08e36507d743367e1de57c359360b64c/0/7818124910159371133,2012-05-10 15:01 /hbase/imagestore/08e36507d743367e1de57c359360b64c/1/5537238047267916113,2012-05-09 19:40 /hbase/imagestore/08e36507d743367e1de57c359360b64c/2/6836317764645542272,2012-05-10 07:04 /hbase/imagestore/08e36507d743367e1de57c359360b64c/3/7276147895747401630,...

因为我想要的只是日期、时间和文件名，所以我只在输入到pig脚本的输出中包含这些字段。当我尝试运行它时，它肯定是在尝试将实际文件加载到 test 别名：

$ pig -p files="`./filesysoutput.sh`" myfirstscript.pig 
2013-05-29 17:40:10.773 java[50830:1203] Unable to load realm info from SCDynamicStore
2013-05-29 17:40:10.827 java[50830:1203] Unable to load realm info from SCDynamicStore
2013-05-29 17:40:20,570 [main] INFO  org.apache.pig.Main - Logging error messages to: /Users/username/Environment/pig-0.9.2-cdh4.0.1/scripts/test/pig_1369863620569.log
2013-05-29 17:40:20,769 [main] INFO  org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to hadoop file system at: hdfs://stage-hadoop101.cluster:8020
2013-05-29 17:40:20,771 [main] WARN  org.apache.hadoop.conf.Configuration - mapred.used.genericoptionsparser is deprecated. Instead, use mapreduce.client.genericoptionsparser.used
2013-05-29 17:40:20,773 [main] WARN  org.apache.hadoop.conf.Configuration - fs.default.name is deprecated. Instead, use fs.defaultFS
2013-05-29 17:40:20.836 java[50847:1203] Unable to load realm info from SCDynamicStore
2013-05-29 17:40:20.879 java[50847:1203] Unable to load realm info from SCDynamicStore
2013-05-29 17:40:21,138 [main] WARN  org.apache.hadoop.conf.Configuration - fs.default.name is deprecated. Instead, use fs.defaultFS
2013-05-29 17:40:21,452 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 1200: Pig script failed to parse: 
<file myfirstscript.pig, line 3, column 7> pig script failed to validate: java.lang.IllegalArgumentException: java.net.URISyntaxException: Relative path in absolute URI: 2012-07-27 17:56%20/hbase/imagestore/.tableinfo.0000000001
Details at logfile: /Users/username/Environment/pig-0.9.2-cdh4.0.1/scripts/test/pig_1369863620569.log

hadoop hdfs apache-pig

来源：https://stackoverflow.com/questions/16824499/pig-how-to-load-the-output-of-an-hdfs-ls-into-an-alias

2条答案

按热度按时间

vshtjzan1#

使用基于java或python的嵌入式pig怎么样？
嵌入式清管器

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uqzxnwby2#

您可以尝试另一种方法-使用dummy.txt输入文件（只有一行），然后使用 STREAM alias THROUGH 命令来处理 hadoop fs -ls 你现在是：

grunt> dummy = load '/tmp/dummy.txt';   
grunt> fs -cat /tmp/dummy.txt;
dummy
grunt> files = STREAM dummy THROUGH 
    `hadoop fs -ls -R /hbase/imagestore | grep '\-rw' | awk 'BEGIN { OFS="\t"; FS = ",[ \t]*|[ \t]+" } {print $6, $7, $8}'` 
    AS (moddate:chararray, modtime:chararray, filename:chararray);

注意上面的内容没有经过测试-我模拟了一些与本地模式pig类似的东西，并且它工作正常（注意我在awk-ofs中添加了一些选项，并且不得不稍微更改grep）：

grunt> files = STREAM dummy THROUGH \
    `ls -l | grep "\\-rw" | awk 'BEGIN { OFS = "\t"; FS = ",[ \t]*|[ \t]+" } {print $6, $7, $9}'` \
     AS (month:chararray, day:chararray, file:chararray);

grunt> dump files

(Dec,31,CTX.DAT)
(Dec,23,examples.desktop)
(Feb,8,installer.img.gz)
(Feb,8,install.py)
(Apr,25,mapred-site.xml)
(Apr,14,sqlite)

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pig：如何将hdfs ls的输出加载到别名中？

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