Most answered questions in Big Data Hadoop

0 votes
13 answers

What is the difference between Hadoop/HDFS & HBase?

HDFS is a distributed file system whereas ...READ MORE

Apr 26, 2019 in Big Data Hadoop by Arihar
• 160 points
16,831 views
0 votes
12 answers

What is Zookeeper? What is the purpose of Zookeeper in Hadoop Ecosystem?

Hey, Apache Zookeeper says that it is a ...READ MORE

Apr 29, 2019 in Big Data Hadoop by Gitika
• 29,010 points
9,453 views
0 votes
11 answers

How to check size of HDFS directory?

It is the same syntax. Use the ...READ MORE

Jun 6, 2019 in Big Data Hadoop by Sowmya
17,102 views
0 votes
11 answers

What is the command to start Job history server in Hadoop 2.x & how to get its UI?

mr-jobhistory-daemon. sh start historyserver READ MORE

Jul 23, 2019 in Big Data Hadoop by Lokesh Singh
7,902 views
0 votes
11 answers

What is the default Namenode port of HDFS. Is it 8020 or 9000 or 50070?

8020/9000 hadoop namenode metadata port number. or ...READ MORE

Dec 31, 2018 in Big Data Hadoop by SM
22,695 views
+10 votes
11 answers

Hadoop “Unable to load native-hadoop library for your platform” warning

modify the glibc version.CentOS provides safe softwares ...READ MORE

Sep 10, 2018 in Big Data Hadoop by bug_seeker
• 15,390 points
23,756 views
+1 vote
11 answers

hadoop fs -put command?

put syntax: put <localSrc> <dest> copy syntax: copyFr ...READ MORE

Dec 7, 2018 in Big Data Hadoop by Aditya
29,655 views
0 votes
10 answers

Difference between single node & pseudo-distributed mode in Hadoop?

Single node is used for debugging the ...READ MORE

Dec 7, 2018 in Big Data Hadoop by Mahisha
6,822 views
+2 votes
10 answers

Is there any difference between “hdfs dfs” and “hadoop fs” shell commands?

Yes, there's a difference between hadoop fs and ...READ MORE

Dec 7, 2018 in Big Data Hadoop by Kunal
14,680 views
0 votes
10 answers

What is the difference between Mongodb and Hadoop?

Apart from the similarity that they are ...READ MORE

Dec 6, 2018 in Big Data Hadoop by Deeraj
4,600 views
0 votes
9 answers

Is there any way to check which Hadoop daemons are running?

use jps command, It will show all the running ...READ MORE

Dec 27, 2018 in Big Data Hadoop by Rakesh
• 160 points
15,355 views
0 votes
7 answers

How to run a jar file in hadoop?

I used this command to run my ...READ MORE

Dec 10, 2018 in Big Data Hadoop by Dasinto
9,363 views
0 votes
5 answers

Hadoop hdfs: list all files in a directory and its subdirectories

Hi, You can try this command: hadoop fs -ls ...READ MORE

Aug 1, 2019 in Big Data Hadoop by Dinish
4,959 views
+2 votes
5 answers

Not able to start hadoop dfs

You can re-install openssh-client and openssh-server: $ sudo ...READ MORE

Oct 25, 2018 in Big Data Hadoop by Jino
560 views
+2 votes
5 answers

How to transpose/pivot data in hive?

Below is also a way for Pivot SELECT ...READ MORE

Oct 12, 2018 in Big Data Hadoop by Rahul
9,536 views
+3 votes
5 answers

Hadoop DistributedCache is deprecated - what is the preferred API?

I had the same problem. And not ...READ MORE

Oct 12, 2018 in Big Data Hadoop by Rohan
516 views
0 votes
5 answers

What is the HDFS command to list all the files in HDFS according to the timestamp?

You can try filter using value in ...READ MORE

Dec 7, 2018 in Big Data Hadoop by Lenny
19,645 views
+2 votes
4 answers

Datanode process not running in Hadoop

Run the following commands: Stop-all.sh start-dfs.sh start-yarn.sh mr-jobhistory-daemon.sh ...READ MORE

Oct 25, 2018 in Big Data Hadoop by Anand
1,971 views
0 votes
3 answers

Sqoop: java.lang.RuntimeException: Could not load db driver class: com.mysql.jdbc.Driver

I add mysql driver for sqoop and it ...READ MORE

Mar 1 in Big Data Hadoop by Manh Quang
• 180 points
998 views
0 votes
3 answers

How to change the delimiter in Sqoop?

--fields-terminated-by <char> READ MORE

Jun 25, 2019 in Big Data Hadoop by anonymous
3,453 views
0 votes
3 answers

Spark Scala: How to list all folders in directory

val spark = SparkSession.builder().appName("Demo").getOrCreate() val path = new ...READ MORE

Dec 4, 2018 in Big Data Hadoop by Mark
4,895 views
0 votes
3 answers

Hadoop Spark: How to iterate hdfs directories?

import org.apache.hadoop.fs.{FileSystem,Path} FileSystem.get( sc.hadoopConfiguration ).listStatus( new Path("hdfs:///tmp")).foreach( ...READ MORE

Dec 4, 2018 in Big Data Hadoop by Komal
5,318 views
+1 vote
3 answers

HIVE: java.net.URISyntaxException

Change in hfs-site.xml this properties <name>hive.exec.scratchdir</name> <value>/tmp/hive-${user.name}</value> <name>hive.exec.local.scratchdir</name> <value>/tmp/${user.name}</value> <name>hive.downloaded.resources.dir</name> <value>/tmp/${user.name}_resources</value> <name>hive.scratch.dir.permission</name> ...READ MORE

Dec 4, 2018 in Big Data Hadoop by Roshan
535 views
0 votes
3 answers

How to specify KeyValueTextInputFormat Separator in Hadoop-.20 api?

conf.set("key.value.separator.in.input.line", ","); Job job = new J ...READ MORE

Dec 4, 2018 in Big Data Hadoop by Rio
370 views
+4 votes
3 answers

Unable to find file error- while Streaming Hadoop

Is python installed running on the slaves that ...READ MORE

Oct 16, 2018 in Big Data Hadoop by Vinith
654 views
+1 vote
3 answers

when i tried to run the hdfs namenode -format command...its failed to run..can anyone help me with this???

Hi Suriyaprakash, I guess the path for hadoop ...READ MORE

Jul 23, 2018 in Big Data Hadoop by avi_man_utd
1,928 views
0 votes
3 answers

How to connect Spark to a remote Hive server?

JDBC is not required here. Create a hive ...READ MORE

Mar 8, 2019 in Big Data Hadoop by Vijay Dixon
• 190 points
2,604 views
0 votes
3 answers

Cloudera Hadoop - Daemons not running

Please run below mentioned command. It will ...READ MORE

Aug 7, 2018 in Big Data Hadoop by Priyaj
• 57,530 points
858 views
0 votes
3 answers

Can we run Spark without using Hadoop?

No, you can run spark without hadoop. ...READ MORE

May 7, 2019 in Big Data Hadoop by pradeep
317 views
0 votes
3 answers

What are differences between NameNode and Secondary NameNode?

File metadata information is stored by Namenode ...READ MORE

Apr 7, 2019 in Big Data Hadoop by anonymous
3,512 views
0 votes
3 answers

What is Hive? Is Hive a database?

Hive is a data Warehouse infrastructure/system built ...READ MORE

Jul 1, 2019 in Big Data Hadoop by Ved Gupta
11,412 views
0 votes
2 answers

How to set properties for secondary namenode in Hadoop?

Secondary NameNode in HDFS Secondary NameNode in Hadoop ...READ MORE

Mar 31 in Big Data Hadoop by anonymous
55 views
+1 vote
2 answers

How to find previous records from a data set in Pig??

Hi, You can use ToDate() and SubtractDuration() function ...READ MORE

Jan 23 in Big Data Hadoop by MD
• 21,340 points
102 views
+1 vote
2 answers

Unable to create external table on HIVE

Hi @Ozer, This error occurred because there is ...READ MORE

Nov 6, 2019 in Big Data Hadoop by Richa
709 views
+1 vote
2 answers

How to find the database daily refresh time / sync up time

I use this code to get the ...READ MORE

Sep 17, 2019 in Big Data Hadoop by Raman
113 views
0 votes
2 answers

How to use scoop in a Java Program

There is a trick which worked out ...READ MORE

Sep 4, 2019 in Big Data Hadoop by ravikiran
• 4,600 points
239 views
+1 vote
2 answers

Error: com/eng/mr/WordCountDriver : Unsupported major.minor version 52.0

The reason why you get this error ...READ MORE

Aug 6, 2019 in Big Data Hadoop by Venkita
• 240 points
82 views
+1 vote
2 answers

Hadoop: Error: Exception in thread “main” java.lang.UnsupportedClassVersionError: a

The reason for this error is because ...READ MORE

Aug 6, 2019 in Big Data Hadoop by Venkita
• 240 points
270 views
+1 vote
2 answers

Hadoop Administration

Make the following changes to your configuration ...READ MORE

Aug 5, 2019 in Big Data Hadoop by Simran
91 views
0 votes
2 answers

Namenode is not getting started

Hi, You can do one thing, first delete all ...READ MORE

Aug 5, 2019 in Big Data Hadoop by Namisha
125 views
0 votes
2 answers

Error in running hdfs commands

Hey, You can check this command also  hadoop fs ...READ MORE

Aug 5, 2019 in Big Data Hadoop by Rashi
107 views
0 votes
2 answers

Exception in thread "main" java.lang.UnsupportedClassVersionError

Hi, keep in mind do not forget to ...READ MORE

Aug 5, 2019 in Big Data Hadoop by Rashi
165 views
0 votes
2 answers

How to set up Map and Reduce Tasks?

Hi, The number of map tasks for a ...READ MORE

Aug 5, 2019 in Big Data Hadoop by Rashi
222 views
0 votes
2 answers

What is the relationship between Hadoop and Database?

Hadoop software framework work is very well ...READ MORE

Aug 6, 2019 in Big Data Hadoop by Dinesh
148 views
0 votes
2 answers

E0901: Namenode [localhost:8020] not allowed, not in Oozies whitelist

You can add this below property in oozie-site.xml: <property> <name>oozie.service.HadoopAccessorService.jobTracker.whitelist</name> <value>myaddress:8020</value> </property> Hope ...READ MORE

Aug 6, 2019 in Big Data Hadoop by Shiva
252 views
0 votes
2 answers

What is ElasticSearch Hadoop?

it as a connector that allows data to flow bi-directionaly so ...READ MORE

Aug 6, 2019 in Big Data Hadoop by Dinish
259 views
0 votes
2 answers

Explain to me the difference between Name Node and Secondary Name Node

Secondary namenode is just a helper for ...READ MORE

Aug 6, 2019 in Big Data Hadoop by Dhiman
203 views
0 votes
2 answers

if HDFS threshold has been reached. What is the our approach to resolve this issue?

This was a fundamental issue in HDFS ...READ MORE

Jun 24, 2019 in Big Data Hadoop by Gitika
• 29,010 points
151 views
0 votes
2 answers

Error While Running Oozie Project

You need to add your current user ...READ MORE

Aug 6, 2019 in Big Data Hadoop by Dhimanshu
83 views
0 votes
2 answers

Why we require SSH during hadoop installation?

Hey, SSH setup is required to do different ...READ MORE

Jun 11, 2019 in Big Data Hadoop by Gitika
• 29,010 points

edited Jun 11, 2019 by Gitika 492 views