Most viewed questions in Big Data Hadoop

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How can you transfer data from hive to HDFS ?

Hey, Data in Hive tables reside on HDFS, ...READ MORE

May 16, 2019 in Big Data Hadoop by Gitika
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2,798 views
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1 answer

Why HBase is column oriented database?

Hey, Yes, Hbase is known to be a ...READ MORE

May 20, 2019 in Big Data Hadoop by Gitika
• 65,770 points
2,797 views
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Moving files in Hadoop using the Java API?

I would recommend you to use FileSystem.rename(). ...READ MORE

Apr 15, 2018 in Big Data Hadoop by Shubham
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2,790 views
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Hadoop: ERROR1070: Could not resolve count using imports: [, java.lang., org.apache.pig.builtin., org.apache.pig.impl.builtin.]

Hi, I can see the error arose because the count ...READ MORE

Aug 7, 2019 in Big Data Hadoop by Gitika
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2,785 views
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How to connect Sqoop to mysql Database?

Hi. You can connect Sqoop to MySql ...READ MORE

May 15, 2019 in Big Data Hadoop by Tina
2,775 views
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How to check the name of the hadoop server?

Hi@akhtar, If you're running a pseudo-distributed setup, you ...READ MORE

Oct 13, 2020 in Big Data Hadoop by MD
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2,764 views
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Error running hadoop mapreduce in Python using Hadoop Streaming

Hi As you write mapper and reducer program  ...READ MORE

Jan 21, 2020 in Big Data Hadoop by anonymous
2,763 views
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1 answer

What is the difference between a zero reducer and identity reducer in Hadoop Mapreduce?

A Zero reducer as the name suggests ...READ MORE

Apr 10, 2018 in Big Data Hadoop by kurt_cobain
• 9,350 points
2,760 views
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Understanding Hadoop Master Node, Slave Node and Data Node.

The NameNode and the JobTracker are single ...READ MORE

Sep 6, 2018 in Big Data Hadoop by Frankie
• 9,830 points
2,758 views
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Can a table be renamed in hive?

Hey, Yes, you can rename a table in ...READ MORE

Jun 26, 2019 in Big Data Hadoop by Gitika
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2,757 views
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What is the difference between local file system commands touch and touchz?

Actually they both do the same except touchz is ...READ MORE

Aug 14, 2018 in Big Data Hadoop by Frankie
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2,753 views
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How to change default block size in Hadoop Cluster?

Hi@akhtar, You can change the default block size ...READ MORE

Oct 3, 2020 in Big Data Hadoop by MD
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2,747 views
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Sqoop error while trying to connect to MySql

Please use the below command to solve ...READ MORE

May 22, 2019 in Big Data Hadoop by Bhagavath
2,744 views
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Hadoop: How to keep duplicates in Hive using collect_set()?

SELECT hash_id, COLLECT_LIST(num_of_cats) AS ...READ MORE

Nov 2, 2018 in Big Data Hadoop by Omkar
• 69,220 points
2,743 views
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What are the different types of tombstone markers in HBase for deletion?

1)Family Delete Marker- This markers marks all ...READ MORE

Dec 17, 2018 in Big Data Hadoop by Frankie
• 9,830 points
2,737 views
0 votes
1 answer

How to open MySql console in Ubuntu?

sudo service mysqld restart mysql -u <username> root ...READ MORE

Dec 14, 2018 in Big Data Hadoop by Omkar
• 69,220 points
2,737 views
+2 votes
1 answer

windows 10 C:\Users\mk>hadoop -version output:- Error: Could not find or load main class P.

Hey, I guess the error you are facing ...READ MORE

May 10, 2019 in Big Data Hadoop by Gitika
• 65,770 points
2,732 views
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How to format the output being written by MapReduce in Hadoop?

Here is a simple code demonstrate the ...READ MORE

Sep 5, 2018 in Big Data Hadoop by Frankie
• 9,830 points
2,731 views
0 votes
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How to create a Hive Database and store it in HDFS?

You will have to exclusively mention the ...READ MORE

May 20, 2019 in Big Data Hadoop by Jishnu
2,729 views
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HIve sql multiple conditions in where cluase

Hi, My table has created_date, changed_date in datetime ...READ MORE

Feb 12, 2020 in Big Data Hadoop by syam
• 120 points

edited Feb 12, 2020 by Gitika 2,726 views
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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
• 69,220 points
2,721 views
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1 answer

What is the standard way to create files in your hdfs file-system?

Well, it's so easy. Just enter the below ...READ MORE

Sep 23, 2018 in Big Data Hadoop by Frankie
• 9,830 points
2,715 views
+1 vote
1 answer

Streaming facebook data using Flume framework!!!

Hi You can find the facebook 'API' from ...READ MORE

Jan 21, 2020 in Big Data Hadoop by anonymous
2,708 views
0 votes
1 answer

Not able to start Job History Server in Hadoop 2.8.1

You have to start JobHistoryServer process specifically ...READ MORE

Mar 30, 2018 in Big Data Hadoop by Ashish
• 2,650 points
2,708 views
0 votes
1 answer

Sqoop ERROR 1290 (HY000): The MySQL server is running with the --secure-file-priv option

If your dataset is in the FTP ...READ MORE

Jul 10, 2019 in Big Data Hadoop by Kunal
2,697 views
0 votes
1 answer

User:hdfs not allowed to do 'DECRYPT_EEK' on 'key'.

Hi@Shilpa, I don't think you have given permission ...READ MORE

Nov 20, 2020 in Big Data Hadoop by MD
• 95,460 points
2,694 views
0 votes
1 answer

Explain to me the correct way to get a Hadoop FileSystem object so that I can use it for reading from HDFS as well as writing to HDFS.

FileSystem needs only one configuration key to successfully ...READ MORE

Jun 7, 2019 in Big Data Hadoop by ravikiran
• 4,620 points
2,693 views
0 votes
1 answer

How to read more than one files in Apache Spark?

Try this: val text = sc.wholeTextFiles("student/*") text.collect() ...READ MORE

Dec 11, 2018 in Big Data Hadoop by Omkar
• 69,220 points
2,689 views
0 votes
1 answer

Permission denied at hdfs

You can spolve this by adding below ...READ MORE

Sep 27, 2018 in Big Data Hadoop by digger
• 26,740 points
2,689 views
0 votes
1 answer

main" java.io.IOException: Mkdirs failed to create /user/hadoop/name.

Hi@akhtar,  I think you missed to add below property ...READ MORE

Apr 17, 2020 in Big Data Hadoop by MD
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2,688 views
0 votes
1 answer

How to fetch more data from database while using Sqoop import?

Hey. You guessed it right. The max ...READ MORE

May 15, 2019 in Big Data Hadoop by Gani
2,688 views
0 votes
1 answer

Parquet & Avro File hadling with HIVE

For avro you can follow the format ...READ MORE

Jul 25, 2019 in Big Data Hadoop by Tarun
2,675 views
0 votes
1 answer

which of the following are hadoop built in counters?

MapReduce in Hadoop maintains some built-in counters ...READ MORE

Dec 20, 2021 in Big Data Hadoop by Kavya
• 700 points
2,674 views
0 votes
1 answer

Hadoop giving java.io.IOException, in mkdir Java code.

I am not sure about the issue. ...READ MORE

May 3, 2018 in Big Data Hadoop by Shubham
• 13,490 points
2,673 views
0 votes
1 answer

Understanding LongWritable

Hadoop needs to be able to serialise ...READ MORE

Oct 29, 2018 in Big Data Hadoop by Frankie
• 9,830 points
2,666 views
–1 vote
1 answer

Namenode not running

Never mind. I forgot to run hadoop namenode ...READ MORE

Dec 27, 2018 in Big Data Hadoop by digger
• 26,740 points
2,665 views
0 votes
1 answer

How to install and configure a multi-node Hadoop cluster?

I would recommend you to install Cent ...READ MORE

Mar 22, 2018 in Big Data Hadoop by Shubham
• 13,490 points
2,661 views
0 votes
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Exception in thread "main" java.lang.NoClassDefFoundError

As far I can make out from ...READ MORE

Aug 9, 2019 in Big Data Hadoop by Arpit
2,660 views
0 votes
1 answer

Junit test for Map Reduce Hadoop

Hi. This is the code I used ...READ MORE

Dec 17, 2018 in Big Data Hadoop by Omkar
• 69,220 points
2,658 views
0 votes
1 answer

Is there any way to pull data from Mainframe to Hadoop?

First of all, COBOL is a programming ...READ MORE

May 21, 2018 in Big Data Hadoop by nitinrawat895
• 11,380 points
2,657 views
0 votes
1 answer

Block Scanner HDFS

Block scanner runs periodically on every DataNode ...READ MORE

Jul 31, 2018 in Big Data Hadoop by kurt_cobain
• 9,350 points
2,654 views
0 votes
1 answer

Passing keys and values to the reducers during a standard sort and shuffle phase of MapReduce

Let me explain you the whole scenario Reducer ...READ MORE

Jul 27, 2018 in Big Data Hadoop by nitinrawat895
• 11,380 points
2,651 views
0 votes
1 answer

Hive queries from mapreduce gives Null Pointer Exception.

I think you have upgraded CDH. This ...READ MORE

Jun 4, 2019 in Big Data Hadoop by Rihan
2,650 views
0 votes
1 answer

How to find the used cache in HDFS

hdfs dfsadmin -report This command tells fs ...READ MORE

May 4, 2018 in Big Data Hadoop by Shubham
• 13,490 points
2,648 views
0 votes
1 answer

Setting Impala host and port in Hue

To set the Impala server details, you ...READ MORE

May 24, 2019 in Big Data Hadoop by Kunal
2,643 views
0 votes
1 answer

INFO hdfs.DFSClient: Could not obtain block blk_-from any node: java.io.IOException: No live nodes contain current block

Hi@akhtar, I think your Datanodes are not in ...READ MORE

Apr 17, 2020 in Big Data Hadoop by MD
• 95,460 points
2,641 views
+1 vote
1 answer

I installed Spark but while executing command, I am getting ‘hadoop’ command not found error?

For accessing Hadoop commands & HDFS, you ...READ MORE

Mar 21, 2018 in Big Data Hadoop by Shubham
• 13,490 points
2,639 views
0 votes
1 answer

Explain to me the difference between HBase and HDFS.

Hadoop generally consists of three major components: HDFS It ...READ MORE

Apr 12, 2019 in Big Data Hadoop by ravikiran
• 4,620 points
2,630 views
0 votes
1 answer

Determining how many mappers will run?

Here what happens is, each file would ...READ MORE

Aug 9, 2018 in Big Data Hadoop by nitinrawat895
• 11,380 points
2,629 views
0 votes
1 answer

failed to start the Namenode format in hadoop generation 2

Hi, You can check this out: 1. Delete all ...READ MORE

Jul 2, 2019 in Big Data Hadoop by Ria

edited Jul 2, 2019 by Gitika 2,628 views