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…

代码缺少这一行:job.setInputFormatClass(KeyValueTextInputFormat.class);…

spark 2.1.1 spark在写数据到hive外部表(底层数据在hbase中)时会报错 Caused by: java.lang.ClassCastException: org.apache.hadoop.hive.hbase.HiveHBaseTableOutputFormat cannot be cast to org.apache.hadoop.hive.ql.io.HiveOutputFormat at org.apache.spark.sql.hive.SparkHiveWrit…

报错 java.lang.Exception: java.lang.ClassCastException: org.apache.hadoop.mapreduce.lib.input.FileSplit cannot be cast to org.apache.hadoop.mapred.FileSplit    at org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:462)    at org.a…

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…

Error: java: 无法访问org.apache.hadoop.mapred.JobConf   找不到org.apache.hadoop.mapred.JobConf的类文件 出现此异常,是缺少相关的依赖包,检查以下四个依赖包是否添加: hadoop-mapreduce-client-core-2.7.2.jar hadoop-common-2.7.2.jar hadoop-mapreduce-client-common-2.7.2.jar hadoop-mapreduce-client…

方法:去掉参数SET hive.auto.convert.join=true; 从配置文件$KYLIN_HOME/conf/kylin_hive_conf.xml删掉 或 kylin-gui的cube的“参数覆盖”页上删掉. 其实关于hive.auto.convert.join kylin用的是  SET hive.auto.convert.join.noconditionaltask=true;…

有一个txt文件,内容格公式是这样的: 深圳订做T恤 5729944 深圳厂家t恤批发 5729945 深圳定做文化衫 5729944 文化衫厂家 5729944 订做文化衫 5729944 深圳t恤厂家 5729945 前面是搜索关键词,后面的是所属的分类ID,以tab分隔,想统计分类情况.于是用以下的MapReduce程序跑了下: import java.io.IOException; import java.util.*; import org.apache.hadoop.fs.Path;…

用java运行Hadoop例程报错:org.apache.hadoop.fs.LocalFileSystem cannot be cast to org.apache.所写代码如下: package com.pcitc.hadoop; import java.io.IOException; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileSystem; import org.apache.h…

执行HBase时常会遇到个错误,我就有这种经历. ERROR: org.apache.hadoop.hbase.MasterNotRunningException: Retried 7 times 检查日志:org.apache.hadoop.ipc.RPC$VersionMismatch: Protocol org.apache.hadoop.hdfs.protocol.ClientProtocol version mismatch. (client = 42, server = 41) 假设…

今天在测试mapreduce的程序时,就是简单的去重,对照课本上的程序和自己的程序,唯一不同的就是“org.apache.hadoop.mapreduce.Reducer.Context context”,我写的程序如下: package com.pro.bq; import java.io.IOException; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.…

What Is Apache Hadoop? Getting Started Download Hadoop Who Uses Hadoop? News 15 October, 2013: release 2.2.0 available 25 August, 2013: release 2.1.0-beta available 27 December, 2011: release 1.0.0 available March 2011 - Apache Hadoop takes top prize…

报错过程: 进入sqoop2之后, 输入命令:show connector,报错 报错现象: Exception has occurred during processing command Exception: java.lang.NoSuchMethodError Message: org.apache.hadoop.security.authentication.client.Authenticator.setConnectionConfigurator(Lorg/apache/hadoo…

Exception in thread "main" java.lang.RuntimeException: org.apache.hadoop.hive.ql.metadata.HiveException: java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient    at org.apache.hadoop.hive…

[root@node1 ~]# hive which: no hbase in (/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/opt/app/jdk1.7.0_79/bin:/opt/app/zookeeper-3.4.9/bin:/opt/app/hadoop-2.7.3/bin:/opt/app/hadoop-2.7.3/sbin:/opt/app/hive-2.1.1/bin:/root/bin) SLF4J:…

Using Spark's default log4j profile: org/apache/spark/log4j-defaults.properties Exception in thread "main" java.io.IOException: java.lang.reflect.InvocationTargetException at org.apache.hadoop.hbase.client.ConnectionFactory.createConnection(Conn…

错误日志如下: [hadoop@master hive1.0.0]$ bin/hive Logging initialized using configuration in file:/opt/modules/hive1.0.0/conf/hive-log4j.properties SLF4J: Class path contains multiple SLF4J bindings. SLF4J: Found binding in [jar:file:/opt/modules/hadoop-2.…

错误日志如下: -- ::, DEBUG [org.apache.hadoop.metrics2.lib.MutableMetricsFactory] - field org.apache.hadoop.metrics2.lib.MutableRate org.apache.hadoop.security.UserGroupInformation$UgiMetrics.loginSuccess with annotation @org.apache.hadoop.metrics2.annotat…

Task with the most failures(): ----- Task ID: task_1555476136794_8201_m_000000 URL: http://hadoop1:8088/taskdetails.jsp?jobid=job_1555476136794_8201&tipid=task_1555476136794_8201_m_000000 ----- Diagnostic Messages for this Task: Error: java.lang.Runt…

前一篇的问题解决了,是 hbase 下面lib 包的jar问题,之前写MR的时候加错了包,替换掉了原来的包后出现另一问题:@ubuntu:/home/hadoop/hbase-0.94.6-cdh4.5.0/bin$ ./start-hbase.sh starting master, logging to /home/hadoop/hbase-0.94.6-cdh4.5.0/logs/hbase-master-ubuntu.outlocalhost: starting regionserver,…

https://my.oschina.net/itblog/blog/275294 摘要: 本文通过一个例子,详细介绍Hadoop 的 MapReduce过程. 分析MapReduce执行过程 MapReduce运行的时候,会通过Mapper运行的任务读取HDFS中的数据文件,然后调用自己的方法,处理数据,最后输出.Reducer任务会接收Mapper任务输出的数据,作为自己的输入数据,调用自己的方法,最后输出到HDFS的文件中.整个流程如图: Mapper任务的执行过程详解 每个Mapper任…

1.MapReduce理论简单介绍 1.1 MapReduce编程模型 MapReduce採用"分而治之"的思想,把对大规模数据集的操作,分发给一个主节点管理下的各个分节点共同完毕,然后通过整合各个节点的中间结果,得到终于结果.简单地说,MapReduce就是"任务的分解与结果的汇总". 在Hadoop中,用于运行MapReduce任务的机器角色有两个:一个是JobTracker:还有一个是TaskTracker,JobTracker是用于调度工作的,TaskTra…

MapReduce任务有三种运行方式: 1.windows(linux)本地调试运行,需要本地hadoop环境支持 2.本地编译成jar包,手动发送到hadoop集群上用hadoop jar或者yarn jar方式运行. 3.本地编译环境在IDE里直接提交到集群上运行,实际上这种方式就是第二种方式的变种. 本例说的就是第三种方式 1)核心的部分就是Confirguration的配置 2)本地需要编译成jar包 3)运行参数在本地配置,包括输入输出参数4)出现windows下的环境配置问题,参照h…

如果之前没有安装jdk和zookeeper,安装了的请直接跳过 # https://www.oracle.com/technetwork/java/javase/downloads/java-archive-javase8-2177648.html # ==================================================================安装 jdk mkdir -p /usr/java tar -zxvf ~/jdk-8u111-linux-x64…

1创建工程 点击project--Maven--next 2通过maven导入项目依赖jar包 (1)设置maven自动导入依赖jar包 勾选 Import Maven projects automatically,点击apply (2)配置pom.xml文件 pom.xml配置文件如下: <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.…

org.apache.hadoop.hbase.client.HTablePool$PooledHTable cannot be cast to org.apac 代码: //1.create HTablePool HTablePool hp=new HTablePool(con, 1000); //2.get HTable from HTablepool HTable ht=(HTable)hp.getTable(tName); 原因:现在应用的api版本号中pool.getTable返回的类…

org.apache.hadoop.hbase.client.HTablePool$PooledHTable cannot be cast to org.apac 代码: //1.create HTablePool HTablePool hp=new HTablePool(con, 1000); //2.get HTable from HTablepool HTable ht=(HTable)hp.getTable(tName); 原因:如今应用的api版本中pool.getTable返回的类型…

[uhadoop@10-13-109-236 subdir26]$ $HADOOP_HOME/bin/hadoop fs -cat /data/flumeEvents/FlumeData.1559805156238WARNING: An illegal reflective access operation has occurredWARNING: Illegal reflective access by org.apache.hadoop.security.authentication.uti…

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…

es for apache hadoop(elasticsearch-hadoop.jar)允许hadoop作业(mapreduce.hive.pig.cascading.spark)与es交互. At the core, elasticsearch-hadoop integrates two distributed systems: Hadoop, a distributed computing platform and Elasticsearch, a real-time search an…