解决办法: 看map和reduce的输入是不是对应,看看map和reduce设置的参数和下面的是否一致…

在Job中添加相应的输入类型,例如: job.setMapOutputKeyClass(Text.class); job.setMapOutputValueClass(IntWritable.class);…

hadoop 编译的程序的报错 执行了命令: hadoop fs -put HTTP_20130313143750.dat /date.dochadoop jar MyDataCount.jar com.liuyang.hadoop.maven.mr.dc.DataCount /date.doc /dateOut 要实现统计报文数据的功能 解决方案: (1)更改这个属性 // 设置Mapper相关属性       job.setMapperClass(DCManager.class);     …

错误: Caused by: java.lang.ClassCastException: class java.lang.Double cannot be cast to class org.apache.hadoop.io.WritableComparable (java.lang.Double is in module java.base of loader 'bootstrap'; org.apache.hadoop.io.WritableComparable is in unnamed…

在 windows 上运行 MapReduce 时报如下异常 Exception in thread "main" java.lang.UnsatisfiedLinkError: org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z at org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Native Method) at or…

hive表在创建时候指定存储格式 STORED AS ORC tblproperties ('orc.compress'='SNAPPY'); 当insert数据到表时抛出异常 Caused by: java.lang.ClassCastException: org.apache.hadoop.io.Text cannot be cast to org.apache.hadoop.hive.ql.io.orc.OrcSerde$OrcSerdeRow at org.apache.hadoop.h…

1.window操作系统的eclipse运行wordcount程序出现如下所示的错误: Exception in thread "main" java.lang.UnsatisfiedLinkError: org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z at org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Native…

错误原因: 你当前开发环境中{Hadoop_HOME}\bin\hadoop.dll 文件和你当前的hadoop版本不匹配.  解决方案: 网络下载相应版本的hadoop.dll,并将该文件放入c:\windows\system32下,同时替换hadoop目录bin下的hadoop.dll 例如: 下载https://codeload.github.com/srccodes/hadoop-common-2.2.0-bin/zip/master下载hadoop-common-2.2.0-bin-m…

在项目中添加src中添加NativeIO类 /** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF lice…

写MR Job的时候遇到一个坑爹的异常: LongWritable cannot be cast to org.apache.hadoop.io.IntWritable 当写Map的时候,key的默认输入就是LongWritable. 因为LongWritable指代Block中的数据偏移量. 所以把它强行转换成Text当然就Error了.. public static class TempMapper extends Mapper<LongWritable, Text, IntWritable…