HDFS command line interface in Hadoop - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to list files in the HDFS root directory.

Hadoop

hdfs dfs -ls [1]

Drag options to blanks, or click blank then click option'

A/tmp

B/data

C/

D/user

Attempts:

3 left

💡 Hint

Common Mistakes

Using a subdirectory like /user instead of root.

Forgetting the leading slash.

The root directory in HDFS is represented by '/'. Using hdfs dfs -ls / lists files and directories at the root.

2fill in blank

medium

Complete the code to copy a local file named 'data.txt' to the HDFS directory '/user/hadoop/'.

Hadoop

hdfs dfs -[1] data.txt /user/hadoop/

Drag options to blanks, or click blank then click option'

Acat

Bput

Cget

Dls

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'get' instead of 'put'.

Using 'cat' which only displays file content.

The put command uploads a local file to HDFS. So hdfs dfs -put data.txt /user/hadoop/ copies the file to HDFS.

3fill in blank

hard

Fix the error in the command to remove the directory '/user/hadoop/temp' and all its contents.

Hadoop

hdfs dfs -rm [1] /user/hadoop/temp

Drag options to blanks, or click blank then click option'

A-r

B-f

C-d

D-R

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-r' (lowercase) instead of '-R'.

Forgetting the recursive flag and getting an error.

The -rm command needs the -R option (recursive) to delete directories with contents. So hdfs dfs -rm -R /user/hadoop/temp works.

4fill in blank

hard

Fill both blanks to display the first 10 lines of the HDFS file '/user/hadoop/log.txt'.

Hadoop

hdfs dfs -[1] /user/hadoop/log.txt | head -[2]

Drag options to blanks, or click blank then click option'

Acat

Btail

C10

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'tail' instead of 'cat' which shows last lines.

Using 'head -5' which shows only 5 lines.

The cat command outputs the file content. Piping it to head -10 shows the first 10 lines.

5fill in blank

hard

Fill all three blanks to create a directory '/user/hadoop/newdir' and then move the file 'data.csv' into it.

Hadoop

hdfs dfs -[1] /user/hadoop/newdir
hdfs dfs -[2] [3] /user/hadoop/newdir/

Drag options to blanks, or click blank then click option'

Amkdir

Bmv

Cdata.csv

Dcp

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'cp' instead of 'mv' which copies instead of moving.

Forgetting to create the directory before moving the file.

First, create the directory with mkdir. Then move the file using mv. The source file is 'data.csv'.