hadoop-plugins

问题 This is regarding an issue I am facing while querying Cassandra from Apache Spark. The normal query from Spark works fine without any issues , however when I query with a condition which is the key I get the below error. Initially I tried querying for a composite key column family and it was also giving the same issue as below. "Caused by: InvalidRequestException(why:empid cannot be restricted by more than one relation if it includes an Equal)" Column Family: CREATE TABLE emp ( empID int,

问题 I just have copied hadoop-eclipse-plugin-1.0.3.jar to the eclipse/plugins directory in order to get things going. But unfortunately it did not work for me. When I tried to connect eclipse to my Hadoop Version 1.1.1 cluster it threw this error : An internal error occurred during: "Map/Reduce location status updater". org/codehaus/jackson/map/JsonMappingException Is there any option to fix this? 回答1: Just follow these steps : 1- Go to your HADOOP_HOME/contrib folder. Copy the hadoop-eclipse

问题 When we run data intensive job over Hadoop. Hadoop executes the job. Now what i want is when the job is completed. it will give me the statistics regarding executed job i.e; time consumed, mapper quantity, reducer quantity and other useful information. The information displayed in browser like job tracker, data node during the job execution. But how can i get the statistics in my application which runs the job over Hadoop and gives me results like a report at the end of job completion. My

问题 There are notice about what how cascading/scalding optimized map-side evaluation They use so called Partial Aggregation. Is it actually better approach then Combiners? Are there any performance comparison on some common hadoop tasks(word count for example)? If so wether hadoop will support this in future? 回答1: In practice, there are more benefits from partial aggregation than from use of combiners. The cases where combiners are useful are limited. Also, combiners optimize the amount of

问题 I am a beginner in hadoop using the hadoop's beginners guide book as a tutorial. I am using a mac osx 10.9.2 and hadoop version 1.2.1 I have set all the appropriate class path, when I call echo $PATH in terminal: Here is the result I get: /Library/Frameworks/Python.framework/Versions/2.7/bin:/Users/oladotunopasina/hadoop-1.2.1/hadoop-core-1.2.1.jar:/Users/oladotunopasina/hadoop-1.2.1/bin:/usr/share/grails/bin:/usr/share/groovy/bin:/Users/oladotunopasina/.rvm/gems/ruby-2.1.1/bin:/Users

问题 I want to share large in memory static data(RAM lucene index) for my map tasks in Hadoop? Is there way for several map/reduce tasks to share same JVM? 回答1: Jobs can enable task JVMs to be reused by specifying the job configuration mapred.job.reuse.jvm.num.tasks. If the value is 1 (the default), then JVMs are not reused (i.e. 1 task per JVM). If it is -1, there is no limit to the number of tasks a JVM can run (of the same job). One can also specify some value greater than 1 using the api. 回答2:

问题 I am in scenario where I have two mapreduce jobs. I am more comfortable with python and planning to use it for writing mapreduce scripts and use hadoop streaming for the same. is there a convenient to chain both the jobs following form when hadoop streaming is used? Map1 -> Reduce1 -> Map2 -> Reduce2 I've heard a lot of methods to accomplish this in java, But i need something for Hadoop streaming. 回答1: Here is a great blog post on how to use Cascading and Streaming. http://www.xcombinator.com

问题 Facing duplicate entry problem while inserting to the table. I have been used Hadoop mapper for reading record from file.It success fully reads record from file.But while writing the record to mysql data base by Hadoop reducer, following error occured. java.io.IOException: Duplicate entry '505975648' for key 'PRIMARY' But Mysql table is remains empty.Unable to write the record to mysql table from Hadoop DBWritable reducer. Following is error log: WARNING: com.mysql.jdbc.exceptions.jdbc4

问题 I'm trying to make storage plugin for Hadoop (hdfs) and Apache Drill. Actually I'm confused and I don't know what to set as port for hdfs:// connection, and what to set for location. This is my plugin: { "type": "file", "enabled": true, "connection": "hdfs://localhost:54310", "workspaces": { "root": { "location": "/", "writable": false, "defaultInputFormat": null }, "tmp": { "location": "/tmp", "writable": true, "defaultInputFormat": null } }, "formats": { "psv": { "type": "text", "extensions

问题 I'm trying to set hadoop up on Ubuntu to develop a project. I'm using Ubuntu 12, hadoop 0.18, java6 and Eclipse. Ubuntu OS is running on a virtual machine (VMware). I installed hadoop by following this guide: http://www.michael-noll.com/tutorials/running-hadoop-on-ubuntu-linux-single-node-cluster/ and everything works fine. Then I saw Hadoop provides a plugin for Eclipse. So, by following this guide: http://v-lad.org/Tutorials/Hadoop/13.5%20-%20copy%20hadoop%20plugin.html (even if it's for