Most voted questions in Big Data Hadoop

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Hadoop: Can not start namenode: Unable to load native-hadoop library for your platform

The entries in your .bashrc file looks ...READ MORE

Dec 5, 2018 in Big Data Hadoop by Omkar
• 69,210 points
2,303 views
0 votes
1 answer

How to move Word and PDF documents to Hadoop HDFS?

Try with below commands: hadoop fs -copyFromLocal <localsrc> ...READ MORE

Dec 5, 2018 in Big Data Hadoop by Frankie
• 9,830 points
805 views
0 votes
1 answer

Differentiate: hadoop fs -text vs hadoop fs -cat vs hadoop fs -get

The main difference between -cat and -text ...READ MORE

Dec 5, 2018 in Big Data Hadoop by Frankie
• 9,830 points
3,983 views
0 votes
1 answer

Hadoop mapreduce error: apache.hadoop.mapred.FileAlreadyExistsException: Output directory

Seems like the output file already exists. ...READ MORE

Dec 5, 2018 in Big Data Hadoop by Omkar
• 69,210 points
2,196 views
0 votes
1 answer

Hadoop Hive: Correlating expression cannot contain unqualified column references

Try the following command and see if ...READ MORE

Dec 5, 2018 in Big Data Hadoop by Omkar
• 69,210 points
4,129 views
0 votes
1 answer

Cant find slave on ResourceManager Web UI

Seems like it is running on default ...READ MORE

Dec 5, 2018 in Big Data Hadoop by Omkar
• 69,210 points
1,275 views
0 votes
1 answer

Why Hadoop is not implemented using MPI?

 One of the big features of Hadoop/map-reduce ...READ MORE

Dec 4, 2018 in Big Data Hadoop by Frankie
• 9,830 points
574 views
0 votes
1 answer

How to get absolute path of files in a directory in Hadoop?

You can use HDFS API like the ...READ MORE

Dec 4, 2018 in Big Data Hadoop by Frankie
• 9,830 points
4,202 views
0 votes
1 answer

Unable to set JAVA_HOME path.

Check if bin/start-all.sh doesn't override JAVA_HOME put echo ...READ MORE

Dec 1, 2018 in Big Data Hadoop by Omkar
• 69,210 points
1,269 views
0 votes
1 answer

Hive:Unable to insert values to an array column using "insert".

make a dummy table which has at least one row. INSERT ...READ MORE

Dec 1, 2018 in Big Data Hadoop by Omkar
• 69,210 points
7,804 views
0 votes
1 answer

Hadoop Mapper is failed because of the following error - “Container killed by the ApplicationMaster”

I suggest you include below property files ...READ MORE

Dec 1, 2018 in Big Data Hadoop by Omkar
• 69,210 points
4,738 views
0 votes
1 answer

Unable to move Hadoop Hive tables from Source to Destination.

First, check the permissions of HDFS Directory ...READ MORE

Dec 1, 2018 in Big Data Hadoop by Omkar
• 69,210 points
5,879 views
0 votes
1 answer

How to Upgrade Apache Hadoop from 2.4.1 to 2.6.0

If the downtime is not an issue, ...READ MORE

Nov 30, 2018 in Big Data Hadoop by Frankie
• 9,830 points
1,235 views
0 votes
1 answer

Is Data locality concept applicable for Reducers also?

No, Data-Locality concept applies to MAPPERS only. Reducers ...READ MORE

Nov 30, 2018 in Big Data Hadoop by Frankie
• 9,830 points
1,156 views
0 votes
2 answers

Hadoop error: Input path does not exist

I was able to fix the issue. ...READ MORE

Jan 13, 2019 in Big Data Hadoop by Ponezhil Ramu
13,448 views
0 votes
1 answer

Hadoop: Error: Could not find or load main class com.sun.tools.javac.Main

It looks like the path is not ...READ MORE

Nov 30, 2018 in Big Data Hadoop by Omkar
• 69,210 points
4,933 views
0 votes
1 answer

How to replace characters in string in hive?

You can do it using regexp_replace. This is ...READ MORE

Nov 30, 2018 in Big Data Hadoop by Omkar
• 69,210 points
16,698 views
0 votes
1 answer

Hadoop Job Tracker problem. I cannot connect to http://localhost:50030/

I think you are using new version ...READ MORE

Nov 30, 2018 in Big Data Hadoop by Omkar
• 69,210 points
3,515 views
0 votes
1 answer

How to find the number of blocks a hdfs file is divided into?

Yes. you can use the hadoop fsck command to do ...READ MORE

Nov 30, 2018 in Big Data Hadoop by Omkar
• 69,210 points
5,455 views
0 votes
1 answer

How to delete a file from Hadoop hdfs using java?

Try this: FileSystem fs = FileSystem.get(getConf()); fs.delete(new ...READ MORE

Nov 28, 2018 in Big Data Hadoop by Omkar
• 69,210 points
5,313 views
0 votes
2 answers

How to get column names from Hive table?

To get all the columns of a ...READ MORE

Jun 4, 2019 in Big Data Hadoop by anonymous

edited Jun 4, 2019 by Omkar 18,949 views
0 votes
1 answer

Hive: How to know the path of a created table?

You can use the DESCRIBE command to ...READ MORE

Nov 28, 2018 in Big Data Hadoop by Omkar
• 69,210 points
2,744 views
0 votes
1 answer

Free Hadoop Cluster Experiments

I doubt if there is something which ...READ MORE

Nov 27, 2018 in Big Data Hadoop by Frankie
• 9,830 points
1,368 views
0 votes
1 answer

How to include third party library in Python MapReduce?

Problem has been solved by zipimport. Then I zip chardet to ...READ MORE

Nov 27, 2018 in Big Data Hadoop by Frankie
• 9,830 points
520 views
0 votes
0 answers

Is the Hadoop scalability linear or proportional to number of nodes?

Is it common to see this sentence: ...READ MORE

Nov 27, 2018 in Big Data Hadoop by Jins
• 140 points
973 views
0 votes
1 answer

How to find the running namenodes and secondary name nodes in hadoop?

Name nodes: hdfs getconf -namenodes Secondary name nodes: hdfs getconf ...READ MORE

Nov 26, 2018 in Big Data Hadoop by Omkar
• 69,210 points
2,349 views
0 votes
1 answer

Hadoop: namenode -format error "java.io.IOException"

Run the command as sudo or add the ...READ MORE

Nov 26, 2018 in Big Data Hadoop by Omkar
• 69,210 points
3,070 views
0 votes
1 answer

How to use mountable HDFS on Centos?

Hey. You can use the following commands ...READ MORE

Nov 26, 2018 in Big Data Hadoop by Omkar
• 69,210 points
1,800 views
0 votes
1 answer

Not able to run mapreduce job. Attempt failes error

The most common reason for this is ...READ MORE

Nov 22, 2018 in Big Data Hadoop by Omkar
• 69,210 points
949 views
0 votes
1 answer

What is the command to count number of lines in a file in hdfs?

hadoop fs -cat /example2/doc1 | wc -l READ MORE

Nov 22, 2018 in Big Data Hadoop by Omkar
• 69,210 points
3,259 views
0 votes
1 answer

Hadoop hdfs "permission denied" error when I try to make new directory

This is because you dont have enough ...READ MORE

Nov 22, 2018 in Big Data Hadoop by Omkar
• 69,210 points
14,788 views
0 votes
1 answer

Apache Spark gives "Failed to load native-hadoop with error"

Seems like hadoop path is missing in java.library.path. ...READ MORE

Nov 22, 2018 in Big Data Hadoop by Omkar
• 69,210 points
2,441 views
0 votes
1 answer

What is the usage of Configured class in Hadoop programs?

Configured is a default implementation of the Configurable interface - ...READ MORE

Nov 22, 2018 in Big Data Hadoop by Frankie
• 9,830 points
1,060 views
0 votes
1 answer

Which is the easiest way for text analytics with hadoop?

Apache pig provides CSVExcelStorage class for loading ...READ MORE

Nov 22, 2018 in Big Data Hadoop by Frankie
• 9,830 points
657 views
0 votes
1 answer

Error while connecting to Hive using Java JDBC

Use ​org.apache.hive.jdbc.HiveDriver as your driver ...READ MORE

Nov 22, 2018 in Big Data Hadoop by Omkar
• 69,210 points
1,561 views
0 votes
1 answer

How to check the size of a file in Hadoop HDFS?

You can use the  hadoop fs -ls command to ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Omkar
• 69,210 points
12,649 views
0 votes
1 answer

How to upgrade from Hadoop 1.2 to Hadoop 2.2?

Here's the solution that worked for me: <dependency> ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Omkar
• 69,210 points
406 views
0 votes
1 answer

How to convert Spark data into CSV?

You can use this: df.write .option("header", "true") ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Omkar
• 69,210 points
3,947 views
0 votes
1 answer

What is the hdfs command to check free space available?

You can see the free available space ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Omkar
• 69,210 points
3,201 views
0 votes
1 answer

What is SerDe in Hadoop Hive?

The SerDe interface allows you to instruct ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Akshay
5,420 views
0 votes
1 answer

What is the meaning of Write Ahead Log in Hadoop?

Write Ahead Log (WAL) is a file ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Sunil
1,698 views
0 votes
1 answer

Hadoop: What does RDD mean?

RDD is the acronym for Resilient Distribution ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Deepak
907 views
0 votes
1 answer

What is the difference between Apache ZooKeeper and Apache Oozie?

The main difference between these two is ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Anoop
3,961 views
0 votes
1 answer

Hadoop: How to get the column name along with the output in Hive?

You can get the column names by ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Omkar
• 69,210 points
4,589 views
0 votes
1 answer

Hadoop: Java code to get Hive table properties.

You can try this: org.apache.hadoop.hive.metastore.api.Table table=..........; org.apache.hadoop.hive.metastore.api.StorageDescriptor sd=table.getSd(); String loc=sd.getLocation(); String ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Omkar
• 69,210 points
695 views
0 votes
1 answer

Hadoop Java: org.apache.hadoop.conf.Configuration does not exist error

To solve this error, add hadoop-common to ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Omkar
• 69,210 points
6,957 views
0 votes
1 answer

In Hadoop MapReduce, how can i set an Object as the Value for Map output?

Try this and see if it works: public ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Omkar
• 69,210 points
749 views
0 votes
1 answer

Hadoop HDFS: Exception in createBlockOutputStream

It's a connection error. Have you turned ...READ MORE

Nov 21, 2018 in Big Data Hadoop by Omkar
• 69,210 points
4,609 views
0 votes
1 answer

Hadoop: "Caused by: java.lang.ClassNotFoundException" error

Have you placed the jar files in ...READ MORE

Nov 19, 2018 in Big Data Hadoop by Omkar
• 69,210 points
6,532 views
0 votes
1 answer

Hadoop hdfs: How to count number of lines?

You can count the number of lines ...READ MORE

Nov 19, 2018 in Big Data Hadoop by Omkar
• 69,210 points
916 views