I am newer to Hadoop, and want to know what is the differences between Hadoop-common, Hadoop-core and Hadoop-client?
By the way,for a given class, how do I know which... moreI am newer to Hadoop, and want to know what is the differences between Hadoop-common, Hadoop-core and Hadoop-client?
By the way,for a given class, how do I know which artifact contains it in Maven ? For example, which one contains the org.apache.hadoop.io.Text?
I'm currently configuring hadoop on a server running CentOs. When I run start-dfs.sh or stop-dfs.sh, I get the following error:WARN util.NativeCodeLoader: Unable to load... moreI'm currently configuring hadoop on a server running CentOs. When I run start-dfs.sh or stop-dfs.sh, I get the following error:WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicableI'm running Hadoop 2.2.0.Doing a search online brought up this link: http://balanceandbreath.blogspot.ca/2013/01/utilnativecodeloader-unable-to-load.htmlHowever, the contents of /native/ directory on hadoop 2.x appear to be different so I am not sure what to do.I've also added these two environment variables in hadoop-env.sh:export HADOOP_OPTS="$HADOOP_OPTS -Djava.library.path=/usr/local/hadoop/lib/"export HADOOP_COMMON_LIB_NATIVE_DIR="/usr/local/hadoop/lib/native/"Any ideas? less
How to copy file from HDFS to the local file system . There is no physical location of a file under the file , not even directory . how can i moved them to my local for further... moreHow to copy file from HDFS to the local file system . There is no physical location of a file under the file , not even directory . how can i moved them to my local for further validations.i am tried through winscp
In many real-life situations where you apply MapReduce, the final algorithms end up being several MapReduce steps.
i.e. Map1 , Reduce1 , Map2 , Reduce2 , and so on.
So you have... moreIn many real-life situations where you apply MapReduce, the final algorithms end up being several MapReduce steps.
i.e. Map1 , Reduce1 , Map2 , Reduce2 , and so on.
So you have the output from the last reduce that is needed as the input for the next map.
The intermediate data is something you (in general) do not want to keep once the pipeline has been successfully completed. Also because this intermediate data is in general some data structure (like a 'map' or a 'set') you don't want to put too much effort in writing and reading these key-value pairs.
What is the recommended way of doing that in Hadoop?
Is there a (simple) example that shows how to handle this intermediate data in the correct way, including the cleanup afterward? less
I am trying to implement one sample word count program using Hadoop. I have downloaded and installed Hadoop 2.0.0. I want to do this sample program using Eclipse because i think... moreI am trying to implement one sample word count program using Hadoop. I have downloaded and installed Hadoop 2.0.0. I want to do this sample program using Eclipse because i think later in my real project I have to use Eclipse only.
I am not able to find Hadoop related jar files like hadoop-core.jar and other required jar files. I searched in all the folders of 2.0 hadoop but couldn't find those files. Those same files are available in 1.0 version of Hadoop but not in 2.0 version. I would like to know where can I get these files?
I am not able to find much information about 2.0 version.
please help less
I am getting the following error while starting namenode for latest hadoop-2.2 release. I didn't find winutils exe file in hadoop bin folder. I tried below commands
$ bin/hdfs... moreI am getting the following error while starting namenode for latest hadoop-2.2 release. I didn't find winutils exe file in hadoop bin folder. I tried below commands
$ bin/hdfs namenode -format
$ sbin/yarn-daemon.sh start resourcemanager
ERROR util.Shell (Shell.java:getWinUtilsPath(303)) - Failed to locate the winutils binary in the hadoop binary path
java.io.IOException: Could not locate executable null\bin\winutils.exe in the Hadoop binaries.
at org.apache.hadoop.util.Shell.getQualifiedBinPath(Shell.java:278)
at org.apache.hadoop.util.Shell.getWinUtilsPath(Shell.java:300)
at org.apache.hadoop.util.Shell.<clinit>(Shell.java:293)
at org.apache.hadoop.util.StringUtils.<clinit>(StringUtils.java:76)
at org.apache.hadoop.yarn.server.resourcemanager.ResourceManager.main(ResourceManager.java:863) less
I am trying to run a simple NaiveBayesClassifer using hadoop, getting this error
Exception in thread "main" java.io.IOException: No FileSystem for scheme: file
at... moreI am trying to run a simple NaiveBayesClassifer using hadoop, getting this error
Exception in thread "main" java.io.IOException: No FileSystem for scheme: file
at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:1375)
at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:66)
at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:1390)
at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:196)
at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:95)
at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:180)
at org.apache.hadoop.fs.Path.getFileSystem(Path.java:175)
at org.apache.mahout.classifier.naivebayes.NaiveBayesModel.materialize(NaiveBayesModel.java:100)
Code :
Configuration configuration = new Configuration();
NaiveBayesModel model = NaiveBayesModel.materialize(new Path(modelPath), configuration);// error in this line..
modelPath is pointing to NaiveBayes.bin file, and configuration object is printing... less
Is there a way to work in Pycharm in local system (mac) which connect and execute the code via jupyter installed on Hadoop edge nodes ?
We have a requirement from data scientist... moreIs there a way to work in Pycharm in local system (mac) which connect and execute the code via jupyter installed on Hadoop edge nodes ?
We have a requirement from data scientist who would like to read data from HDFS using spark and plot some graphs or run some models in pycharm (mac) snippet by snippet.
Really interested to know if this model is possible or how generally data scientist work in big data eco system from local machine to read data from HDFS to run some models ?
What are the benefits of using either Hadoop or HBase or Hive ?
From my understanding, HBase avoids using map-reduce and has a column oriented storage on top of... moreWhat are the benefits of using either Hadoop or HBase or Hive ?
From my understanding, HBase avoids using map-reduce and has a column oriented storage on top of HDFS. Hive is a sql-like interface for Hadoop and HBase.
I would also like to know how Hive compares with Pig.
Are they supposed to be equal?
but, why the "hadoop fs" commands show the hdfs files while the "hdfs dfs" commands show the local files?
here is the hadoop version... moreAre they supposed to be equal?
but, why the "hadoop fs" commands show the hdfs files while the "hdfs dfs" commands show the local files?
here is the hadoop version information:
Hadoop 2.0.0-mr1-cdh4.2.1 Subversion git://ubuntu-slave07.jenkins.cloudera.com/var/lib/jenkins/workspace/CDH4.2.1-Packaging-MR1/build/cdh4/mr1/2.0.0-mr1-cdh4.2.1/source -r Compiled by jenkins on Mon Apr 22 10:48:26 PDT 2013
I'm currently configuring hadoop on a server running CentOs. When I run start-dfs.sh or stop-dfs.sh, I get the following error:WARN util.NativeCodeLoader: Unable to load... moreI'm currently configuring hadoop on a server running CentOs. When I run start-dfs.sh or stop-dfs.sh, I get the following error:WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicableI'm running Hadoop 2.2.0.Doing a search online brought up this link: http://balanceandbreath.blogspot.ca/2013/01/utilnativecodeloader-unable-to-load.htmlHowever, the contents of /native/ directory on hadoop 2.x appear to be different so I am not sure what to do.I've also added these two environment variables in hadoop-env.sh:export HADOOP_OPTS="$HADOOP_OPTS -Djava.library.path=/usr/local/hadoop/lib/"export HADOOP_COMMON_LIB_NATIVE_DIR="/usr/local/hadoop/lib/native/"Any ideas? less
I tried installing Hadoop following this http://hadoop.apache.org/common/docs/stable/single_node_setup.html document. When I tried executing this
bin/hadoop jar... moreI tried installing Hadoop following this http://hadoop.apache.org/common/docs/stable/single_node_setup.html document. When I tried executing this
bin/hadoop jar hadoop-examples-*.jar grep input output 'dfs+'
I am getting the following Exception
java.lang.OutOfMemoryError: Java heap space
Please suggest a solution so that i can try out the example. The entire Exception is listed below. I am new to Hadoop I might have done something dumb . Any suggestion will be highly appreciated.
anuj@anuj-VPCEA13EN:~/hadoop$ bin/hadoop jar hadoop-examples-*.jar grep input output 'dfs+'
11/12/11 17:38:22 INFO util.NativeCodeLoader: Loaded the native-hadoop library
11/12/11 17:38:22 INFO mapred.FileInputFormat: Total input paths to process : 7
11/12/11 17:38:22 INFO mapred.JobClient: Running job: job_local_0001
11/12/11 17:38:22 INFO util.ProcessTree: setsid exited with exit code 0
11/12/11 17:38:22 INFO mapred.Task: Using ResourceCalculatorPlugin :... less
Is there a way to locate a specific file in hadoop?
I know, that I can use this: hadoop fs -find /some_directory
But, is there a command like this: hadoop locate some_file_name?
I am a relatively new user to Hadoop (using version 2.4.1). I installed hadoop on my first node without a hitch, but I can't seem to get the Resource Manager to start on my second... moreI am a relatively new user to Hadoop (using version 2.4.1). I installed hadoop on my first node without a hitch, but I can't seem to get the Resource Manager to start on my second node.I cleared up some "shared library" problems by adding this to yarn-env.sh and hadoop-env.sh:export HADOOP_HOME="/usr/local/hadoop"export HADOOP_OPTS="-Djava.library.path=$HADOOP_HOME/lib"I also added this to hadoop-env.sh:export HADOOP_COMMON_LIB_NATIVE_DIR=${HADOOP_PREFIX}/lib/nativebased on the advice of this post at horton works http://hortonworks.com/community/forums/topic/hdfs-tmp-dir-issue/That cleared up all of my error messages; when I run /sbin/start-yarn.sh I get this:starting yarn daemonsstarting resourcemanager, logging to /usr/local/hadoop/logs/yarn-hduser-resourcemanager-HdNode.outlocalhost: starting nodemanager, logging to /usr/local/hadoop/logs/yarn-hduser-nodemanager-HdNode.outThe only problem is, JPS says that the Resource Manager isn't running.What's going on here? less
I have a query about how to filter relevant records from a large data set of financial transactions. We use Oracle 11g database and one of the requirements is to produce various... moreI have a query about how to filter relevant records from a large data set of financial transactions. We use Oracle 11g database and one of the requirements is to produce various end-of-day reports with all sorts of criteria.
The relevant tables look roughly like this:
trade_metadata 18m rows, 10 GB
trade_economics 18m rows, 15 GB
business_event 18m rows, 11 GB
trade_business_event_link 18m rows, 3 GB
One of our reports is now taking ages to run ( > 5 hours). The underlying proc has been optimized time and again but new criteria keep getting added so we start struggling again. The proc is pretty standard - join all the tables and apply a host of where clauses (20 at the last count).
I was wondering if I have a problem large enough to consider big data solutions to get rid of this optimize-the-query game every few months. In any case, the volumes are only going up. I have read up a bit about Hadoop + HBase, Cassandra, Apache Pig etc. but being very new to this... less
