How to uninstall or remove Hadoop from Ubuntu ?

Question

I'm not sure my title is the best descriptor of my issue. Consider this minimum working example:

$arr = @()

$object = New-Object -TypeName PSObject
$object | Add-Member –MemberType NoteProperty –Name Name –Value "Fred"
$object | Add-Member –MemberType NoteProperty –Name Rank –Value "2"

$arr += $object

$object = New-Object -TypeName PSObject
$object | Add-Member –MemberType NoteProperty –Name Name –Value "Joe"
$object | Add-Member –MemberType NoteProperty –Name Rank –Value "1"

$arr += $object

$object = New-Object -TypeName PSObject
$object | Add-Member –MemberType NoteProperty –Name Name –Value "Ann"
$object | Add-Member –MemberType NoteProperty –Name Rank –Value "4"

$arr += $object

$arr

($arr | foreach { if($_.Rank -gt 1) { $_ } }).GetType() | FT
($arr | foreach { if($_.Rank -le 1) { $_ } }).GetType() | FT

The output of this is

Name Rank
---- ----
Fred 2   
Joe  1   
Ann  4   



IsPublic IsSerial Name     BaseType    
-------- -------- ----     --------    
True     True     Object[] System.Array



IsPublic IsSerial Name           BaseType     
-------- -------- ----           --------     
True     False    PSCustomObject System.Object

My problem exists when trying to do additional processing on the resultant array of the foreach commands. As you can imagine, the input data for $arr would be different each time and the number of matching results would be different. Depending on the number of matching results the data type is different. What I would like is for both of these to return an array of objects but in the case where there is only one match it returns just the object. If I try to use a calculated index to get information from the array I will get vastly different results depending on if it is an object or an array of objects.

Hoping someone has a solution for me! Thanks!

Solution 1

Actually I just delete the folder hadoop which given permission(shown below) to my HDFS user.

$ sudo rm -r -f /usr/local/hadoop/

Previously I extracted hadoop-2.4.0 and given permission for my HDFS user(hadoopuser - HDFS user),

$ sudo chown -R hadoopuser:hadoop hadoop

After that I removed user(hadoopuser) and group(hadoop)

root@ARUL-PC:~# deluser hadoopuser
Removing user `hadoopuser' ...
Warning: group `hadoop' has no more members.
Done.
root@ARUL-PC:~# deluser --group hadoop
Removing group `hadoop' ...
Done.

Now hadoop-2.4.0 not present in my system.

Note : In my system, configured hadoop folder is /usr/local/hadoop/.

Solution 2

You can uninstall hadoop using:

sudo apt-get purge hadoop-2.4.*

This will remove all packages and configurations related to hadoop from your system.

Comments

[NIMISHAN]

how to check that I removed Hadoop ?

[uhhh_big_mike_boiii]

But hadoop installs so may other things this is not really a complete uninstall is it?

[Tibblez]

Thank you! This simply and perfectly solves my problem.

[Serzhan Akhmetov]

link does not work