MapReduce

How do I learn to use Java commons-collections?

由 久未见 提交于 2019-12-22 06:08:06
问题 Weird title, I know, let me explain. I am a developer most familiar with C# and Javascript. I am completely sunk into those semi-functional worlds to the point that most of my code is about mapping/reducing/filtering collections. In C# that means I use LINQ just about everywhere, in Javascript it's Underscore.js and jQuery. I have currently been assigned to an ongoing Java project and am feeling rather stifled. I simply do not think in terms of "create an array, shuffle stuff from one to

How to reset textinputformat.record.delimiter to its default value within hive cli / beeline?

由 冷暖自知 提交于 2019-12-22 05:57:17
问题 Setting textinputformat.record.delimiter to a non-default value, is useful for loading multi-row text, as shown in the demo below. However, I'm failing to set this parameter back to its default value without exiting the cli and reopen it. None of the following options worked (nor some other trials) set textinputformat.record.delimiter='\n'; set textinputformat.record.delimiter='\r'; set textinputformat.record.delimiter='\r\n'; set textinputformat.record.delimiter=' '; reset; Any thought?

Sqoop - Binding to YARN queues

由 此生再无相见时 提交于 2019-12-22 05:29:07
问题 So with mapreduce v2 you can use binding to certain YARN queues to manage resources and prioritization. Basically by using "hadoop jar /xyz.jar -D mapreduce.job.queuename=QUEUE1 /input /output" which works perfectly. How can integrate Yarn queue binding with Sqoop when you run a sqoop query? ie. sqoop import \ --connect 'jdbc://server' \ --target-dir \ and what ? 回答1: Use the same method for Sqoop as well i.e sqoop import -Dmapreduce.job.queuename=NameOfTheQueue\ --connect 'jdbc://server' \ -

并行计算和MapReduce

由 五迷三道 提交于 2019-12-22 05:18:20
2019-12-01 21:17:38 参考：https://www.iteye.com/blog/xuyuanshuaaa-1172511 现在MapReduce/Hadoop以及相关的数据处理技术非常热，因此我想在这里将MapReduce的优势汇总一下，将MapReduce与传统基于HPC集群的并行计算模型做一个简要比较，也算是对前一阵子所学的MapReduce知识做一个总结和梳理。 　　随着互联网数据量的不断增长，对处理数据能力的要求也变得越来越高。当计算量超出单机的处理能力极限时，采取并行计算是一种自然而然的解决之道。在MapReduce出现之前，已经有像MPI这样非常成熟的并行计算框架了，那么为什么Google还需要MapReduce，MapReduce相较于传统的并行计算框架有什么优势，这是本文关注的问题。 　　文章之初先给出一个传统并行计算框架与MapReduce的对比表格，然后一项项对其进行剖析。　 MapReduce和HPC集群并行计算优劣对比 ▲ 　　在传统的并行计算中，计算资源通常展示为一台逻辑上统一的计算机。对于一个由多个刀片、SAN构成的HPC集群来说，展现给程序员的仍旧是一台计算机，只不过这台计算拥有为数众多的CPU，以及容量巨大的主存与磁盘。在物理上，计算资源与存储资源是两个相对分离的部分，数据从数据节点通过数据总线或者高速网络传输到达计算节点

How do I get last modified date from a Hadoop Sequence File?

由 房东的猫 提交于 2019-12-22 04:19:16
问题 I am using a mapper that converts BinaryFiles (jpegs) to a Hadoop Sequence File (HSF): public void map(Object key, Text value, Context context) throws IOException, InterruptedException { String uri = value.toString().replace(" ", "%20"); Configuration conf = new Configuration(); FSDataInputStream in = null; try { FileSystem fs = FileSystem.get(URI.create(uri), conf); in = fs.open(new Path(uri)); java.io.ByteArrayOutputStream bout = new ByteArrayOutputStream(); byte buffer[] = new byte[1024 *

Hive ParseException - cannot recognize input near 'end' 'string'

由 ≯℡__Kan透↙ 提交于 2019-12-22 04:04:05
问题 I am getting the following error when trying to create a Hive table from an existing DynamoDB table: NoViableAltException(88@[]) at org.apache.hadoop.hive.ql.parse.HiveParser_IdentifiersParser.identifier(HiveParser_IdentifiersParser.java:9123) at org.apache.hadoop.hive.ql.parse.HiveParser.identifier(HiveParser.java:30750) ...more stack trace... FAILED: ParseException line 1:77 cannot recognize input near 'end' 'string' ',' in column specification The query looks like this (simplified to

对话行癫：解密阿里云顶层设计和底层逻辑

由 倾然丶 夕夏残阳落幕 提交于 2019-12-22 03:34:25
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 几十个问题，万字长文，阿里云新任总裁行癫履新后首次出面与钛媒体独家深入讨论了一下阿里云对云计算未来的判断，深度解读未来阿里云生态战略，揭秘阿里技术委员会和阿里中台思想的原生思考。转载自钛媒体，作者：刘湘明 。标题为 《钛媒体独家对话行癫：最详解密阿里云顶层设计和底层逻辑》 。分享给大家。 阿里云智能总裁张建锋 钛媒体注 ：张建锋（花名行癫）的阿里生涯，一直在踩着技术与业务的交界线前进，某种意义上可以看作阿里战略重点转移的缩影——在担任集团CTO和阿里云总裁之前，他先后管过淘宝网技术架构部、B2C开发部及淘宝网产品技术开发部，还分管过聚划算事业部、本地生活事业部、1688事业部及天猫事业部。2015年还担任过阿里中国零售事业群总裁。 2018年11月，还在担任阿里巴巴集团首席技术官，同时也在负责达摩院的张建锋，被任命为阿里云智能事业群总裁。 云计算的市场发展很快，根据调研机构Canalys给出的数据，2018年全球云计算市场规模突破800亿美元，达到804亿美元，同比增长46.5%。市场的高速发展，也带来云生态环境的快速变化，技术、客户需求、伙伴关系都伴随着规模的扩张和应用的深入在不停地演变。 张建锋过往的这些经历，对于他在这个快速变化的云生态环境里，理解技术与业务的关系，切换合作伙伴视角去思考问题

Hadoop 7、MapReduce执行环境配置

由 拥有回忆 提交于 2019-12-22 01:43:11
MR执行环境有两种：本地测试环境，服务器环境 本地测试环境(windows，用于测试) 1、下载Winddows版的Hadoop程序，解压后在Hadoop目录的bin目录放置一个winutils.exe可执行文件（下载地址： http://pan.baidu.com/s/1mhrsQyG ） 2、在windows下配置hadoop的环境变量 HADOOP_HOME E:\big-data\hadoop-2.5.2\hadoop-2.5.2 Path %HADOOP_HOME%\bin;%HADOOP_HOME%\sbin; 3、拷贝debug工具(winutils.ext)到HADOOP_HOME/bin 3、修改hadoop的源码 　　将Hadoop org.apachehadoop.io.nativeio.NativeIO.java 和 org.apachehadoop.mapred.YARNRunner.java拷备到项目的src目录下（包路径也不能变） 　　 　　注意：修改项目JDK，确保项目的lib需要真实安装的jdk的lib，而不是工具自带的JDK 5、MR调用的代码需要改变： 　　a、src不能有服务器的hadoop配置文件 　　b、在调用是使用： Configuration config = new Configuration(); config.set("fs

Creating custom InputFormat and RecordReader for Binary Files in Hadoop MapReduce

由 混江龙づ霸主 提交于 2019-12-22 01:36:14
问题 I'm writing a M/R job that processes large time-series-data files written in binary format that looks something like this (new lines here for readability, actual data is continuous, obviously): TIMESTAMP_1---------------------TIMESTAMP_1 TIMESTAMP_2**********TIMESTAMP_2 TIMESTAMP_3%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%TIMESTAMP_3 .. etc Where timestamp is simply a 8 byte struct, identifiable as such by the first 2 bytes. The actual data is bounded between duplicate value timestamps, as displayed

Hadoop WordCount Example- Run On Hadoop(Eclipse) option is not prompting Select Hadoop server to run on window

由 天涯浪子 提交于 2019-12-21 23:19:00
问题 I am trying to run word count example on Eclipse . Generally when we click on "run on hadoop" option in eclipse we get a new window asking to select server location. But, now it is directly running the program without asking me to choose an existing server from list below. I think because of this I am getting the following exception: 13/04/21 08:46:31 ERROR security.UserGroupInformation: PriviledgedActionException as:hduser1 cause:org.apache.hadoop.mapred.InvalidInputException: Input path
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