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Hadoop字数统计MapReduce教程已弃用

[英]Hadoop Word Count MapReduce Tutorial Deprecated

原文 2013-12-26 23:18:06 1 1 java/ hadoop

I have done some work using Python Hadoop Streaming and I think it will be more helpful if I learn Java and begin to learn writing Mapreduce in Java and also have a better understanding of the hadoop code base. 我已经使用Python Hadoop Streaming完成了一些工作，并且我认为如果我学习Java并开始学习用Java编写Mapreduce并更好地了解hadoop代码库，它将对您有所帮助。

I wanted to run the wordcount example and step through every line to learn it. 我想运行wordcount示例并逐步学习每一行。 However, I set up Eclipse and Maven, and finally I let all the red errors go away however, after all of that, in front of me is just paragraphs of deprecated code. 但是，我设置了Eclipse和Maven，最后让所有红色错误消失了，毕竟，在我眼前只是不推荐使用的代码段。

(1). （1）。 Am I just wasting my time to learn something that will not be valid soon? 我是不是在浪费时间学习即将失效的东西？

(2). （2）。 Is it possible to use Eclipse to step through a complete Map Reduce so you can have a good idea of what is going on after every step? 是否可以使用Eclipse逐步完成完整的Map Reduce，以便您对每个步骤之后的工作情况有个很好的了解？ I am not a Java programmer but I am 100% in and want to learn it well. 我不是Java程序员，但我有100％的经验，并且想很好地学习它。 Can anyone point me to the right direction to learn it? 谁能指出我正确的学习方向？ DEBUG? DEBUG？ JUNIT? JUNIT？

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1 个解决方案

firstly, learn Java and MapReduce will lead to a deeper understanding of how MapReduce work. 首先，学习Java和MapReduce将使人们对MapReduce的工作方式有更深入的了解。 The version of Hadoop you used maybe a high version, old MapReduce APIs are deprecated, new APIs are encouraged. 您使用的Hadoop版本可能是高版本，不建议使用旧的MapReduce API，建议使用新的API。

if you want to discover how MR works, you can use remote debug, open the DEBUG level log, use related JUnit test classes, dive into the source code. 如果您想了解MR的工作原理，可以使用远程调试，打开DEBUG级别日志，使用相关的JUnit测试类，并深入研究源代码。

Have fine to learn how MR works. 很好地了解MR的工作原理。