从 HDFS 加载数据不适用于 Elephantbird

Posted 2023-04-13

【中文标题】从 HDFS 加载数据不适用于 Elephantbird

【英文标题】：Loading data from HDFS does not work with Elephantbird

【发布时间】：2013-07-26 10:40:18

【问题描述】：

我正在尝试用猪中的大象鸟处理数据，但我没有成功加载数据。这是我的猪脚本：

register 'lib/elephant-bird-core-3.0.9.jar';
register 'lib/elephant-bird-pig-3.0.9.jar';
register 'lib/google-collections-1.0.jar';
register 'lib/json-simple-1.1.jar';

twitter = LOAD 'statuses.log.2013-04-01-00' 
          USING com.twitter.elephantbird.pig.load.JsonLoader('-nestedLoad');

DUMP twitter;

我得到的输出是

[main] INFO  org.apache.pig.Main - Apache Pig version 0.11.0-cdh4.3.0 (rexported) compiled May 27 2013, 20:48:21
[main] INFO  org.apache.pig.Main - Logging error messages to: /home/hadoop1/twitter_test/pig_1374834826168.log
[main] INFO  org.apache.pig.impl.util.Utils - Default bootup file /home/hadoop1/.pigbootup not found
[main] INFO  org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to hadoop file system at: hdfs://master.hadoop:8020
[main] INFO  org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to map-reduce job tracker at: master.hadoop:8021
[main] INFO  org.apache.pig.tools.pigstats.ScriptState - Pig features used in the script: UNKNOWN
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MRCompiler - File concatenation threshold: 100 optimistic? false
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer - MR plan size before optimization: 1
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer - MR plan size after optimization: 1
[main] WARN  org.apache.pig.backend.hadoop23.PigJobControl - falling back to default JobControl (not using hadoop 0.23 ?)
java.lang.NoSuchFieldException: jobsInProgress
    at java.lang.Class.getDeclaredField(Class.java:1938)
    at org.apache.pig.backend.hadoop23.PigJobControl.<clinit>(PigJobControl.java:58)
    at org.apache.pig.backend.hadoop.executionengine.shims.HadoopShims.newJobControl(HadoopShims.java:102)
    at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler.compile(JobControlCompiler.java:285)
    at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher.launchPig(MapReduceLauncher.java:177)
    at org.apache.pig.PigServer.launchPlan(PigServer.java:1266)
    at org.apache.pig.PigServer.executeCompiledLogicalPlan(PigServer.java:1251)
    at org.apache.pig.PigServer.storeEx(PigServer.java:933)
    at org.apache.pig.PigServer.store(PigServer.java:900)
    at org.apache.pig.PigServer.openIterator(PigServer.java:813)
    at org.apache.pig.tools.grunt.GruntParser.processDump(GruntParser.java:696)
    at org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:320)
    at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:194)
    at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:170)
    at org.apache.pig.tools.grunt.Grunt.exec(Grunt.java:84)
    at org.apache.pig.Main.run(Main.java:604)
    at org.apache.pig.Main.main(Main.java:157)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:208)
[main] INFO  org.apache.pig.tools.pigstats.ScriptState - Pig script settings are added to the job
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - mapred.job.reduce.markreset.buffer.percent is not set, set to default 0.3
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - Using reducer estimator: org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.InputSizeReducerEstimator
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.InputSizeReducerEstimator - BytesPerReducer=1000000000 maxReducers=999 totalInputFileSize=656085089
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - Setting Parallelism to 1
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - creating jar file Job6015425922938886053.jar
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - jar file Job6015425922938886053.jar created
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - Setting up single store job
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - 1 map-reduce job(s) waiting for submission.
[JobControl] WARN  org.apache.hadoop.mapred.JobClient - Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
[JobControl] INFO  org.apache.hadoop.mapreduce.lib.input.FileInputFormat - Total input paths to process : 1
[JobControl] INFO  org.apache.pig.backend.hadoop.executionengine.util.MapRedUtil - Total input paths (combined) to process : 5
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - 0% complete
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - HadoopJobId: job_201307261031_0050
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - Processing aliases twitter
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - detailed locations: M: twitter[10,10] C:  R: 
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - More information at: http://master.hadoop:50030/jobdetails.jsp?jobid=job_201307261031_0050
[main] WARN  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - Ooops! Some job has failed! Specify -stop_on_failure if you want Pig to stop immediately on failure.
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - job job_201307261031_0050 has failed! Stop running all dependent jobs
[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - 100% complete
[main] ERROR org.apache.pig.tools.pigstats.SimplePigStats - ERROR 2997: Unable to recreate exception from backed error: Error: Found interface org.apache.hadoop.mapreduce.Counter, but class was expected
[main] ERROR org.apache.pig.tools.pigstats.PigStatsUtil - 1 map reduce job(s) failed!
[main] INFO  org.apache.pig.tools.pigstats.SimplePigStats - Script Statistics: 

HadoopVersion   PigVersion  UserId  StartedAt   FinishedAt  Features
2.0.0-cdh4.3.0  0.11.0-cdh4.3.0 hadoop1 2013-07-26 12:33:48 2013-07-26 12:34:23 UNKNOWN

Failed!

Failed Jobs:
JobId   Alias   Feature Message Outputs
job_201307261031_0050   twitter MAP_ONLY    Message: Job failed!    hdfs://master.hadoop:8020/tmp/temp971280905/tmp1376631504,

Input(s):
Failed to read data from "hdfs://master.hadoop:8020/user/hadoop1/statuses.log.2013-04-01-00"

Output(s):
Failed to produce result in "hdfs://master.hadoop:8020/tmp/temp971280905/tmp1376631504"

Counters:
Total records written : 0
Total bytes written : 0
Spillable Memory Manager spill count : 0
Total bags proactively spilled: 0
Total records proactively spilled: 0

Job DAG:
job_201307261031_0050


[main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - Failed!
[main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 2997: Unable to recreate exception from backed error: Error: Found interface org.apache.hadoop.mapreduce.Counter, but class was expected
Details at logfile: /home/hadoop1/twitter_test/pig_1374834826168.log

文件存在且可访问：

$ hdfs dfs -ls /user/hadoop1/statuses.log.2013-04-01-00
Found 1 items
-rw-r--r--   3 hadoop1 supergroup  656085089 2013-07-26 11:53 /user/hadoop1/statuses.log.2013-04-01-00

这似乎是 Cloudera 4.6.0 附带的 pig 版本的普遍问题：问题似乎是说

[main] ERROR org.apache.pig.tools.pigstats.SimplePigStats - ERROR 2997: Unable to recreate exception from backed error: Error: Found interface org.apache.hadoop.mapreduce.Counter, but class was expected

在运行另一个用于加载数据的用户定义函数时，我遇到了类似的错误：

[main] ERROR org.apache.pig.tools.pigstats.SimplePigStats - ERROR 2997: Unable to recreate exception from backed error: Error: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected

当我强制 pig 进入本地模式（''-x local''）时，我得到更明显的错误

Caused by: java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected

所以我猜想，Hadoop pig 使用的版本似乎与 Cloudera 附带的版本不兼容。

【参考方案1】：

这确实是一个版本控制问题：一些库还不兼容新的 MapReduce API，例如问题#56、#247 和#308。 对于 ElephantBird，问题是 solved in a recent version。在上述代码中使用 ElephantBird 4.1 并添加 Hadoop 兼容模块

register 'lib/elephant-bird-core-4.1.jar';
register 'lib/elephant-bird-pig-4.1.jar';
register 'lib/elephant-bird-hadoop-compat-4.1.jar';
register 'lib/google-collections-1.0.jar';
register 'lib/json-simple-1.1.jar';

解决了问题！ :-)