question Re: Host file in Support Questions

Host file

MERCEDES0123 — Tue, 13 Jun 2017 13:15:10 GMT

Hi gurus,

Is there a way to identify which is the address to set in the host file? I am trying with 127.0.0.1 and I am getting errors, all the time. I would like to set an address and be able to configure the node in cloudera manager.

Thanks a lot,

Regards,

Re: Host file

csguna — Tue, 13 Jun 2017 13:39:02 GMT

were you able to fix it ? if not i can help you that

Re: Host file

MERCEDES0123 — Tue, 13 Jun 2017 13:40:50 GMT

No, i could not.

I don´t know which is the address that I have to set in the host file.

If you could help me it would be great.

Thanks,

Regards

Re: Host file

csguna — Tue, 13 Jun 2017 13:42:18 GMT

Gotcha . its just matter of two files that you need to tweak.

are you plaining to perform single node or multi node cluster ?

Re: Host file

MERCEDES0123 — Tue, 13 Jun 2017 13:45:03 GMT

it will be a 2 node cluster.

Re: Host file

csguna — Tue, 13 Jun 2017 13:58:00 GMT

I assume you are using vm .

so edit the file accordingly , to perform the SSH configuration follow the link

On both the nodes .

/etc/hosts

192.168.200.201    master
192.168.200.202    slave

On the master node

/etc/sysconfig/network

master

on the slave node

/etc/sysconfig/network

slave

Below is the best link to walk through the rest of the configuration ,mate

https://www.tutorialspoint.com/hadoop/hadoop_multi_node_cluster.htm

Re: Host file

MERCEDES0123 — Tue, 13 Jun 2017 13:59:50 GMT

thanks. what if i am using a single node cluster?

Thanks a lot!

Regards,

Re: Host file

csguna — Tue, 13 Jun 2017 14:11:32 GMT

if you are plaining for Single node cluster ,

then just the hostname would be of your choice .

/etc/hosts
192.168.200.201   Hello

/etc/sysconfig/network

Hello

You have to configure Yum repository , MR2 yarn setup - the below is good link from Cloudera for Single node cluster setup .

https://www.cloudera.com/documentation/enterprise/5-4-x/topics/cdh_qs_yarn_pseudo.html

Re: Host file

mercedes012345 — Tue, 13 Jun 2017 15:58:27 GMT

Great, i will try it. Then with this information, which is the IP that I should look for specifying the hosts? Is this the same that I specified in the hosts file?

Thanks a lot,

Regards,

Re: Host file

mbigelow — Tue, 13 Jun 2017 19:43:28 GMT

@mercedes012345 The hosts file is a mapping between IPs and hostnames. Each lines corresponds to a single entry. The first column if for the IP address, the second column is for the fully qualified domain name, and the last column is for the hostname (columns can be separated by spaces or tabs).

You can have as many entires as needed. I honestly haven't done an install that didn't use DNS first, but unless my memory is failing all hosts need to be resolve each other. So if you are only using hosts files for name resolution you need to include all hosts in the cluster.

@csguna provided some examples. I would flesh it out by include all three columns

/etc/host
192.168.1.1  master.example.com  master
192.168.1.2  worker.example.com  worker

The hostname in the network file should be in the format of HOSTNAME=master.example.com

Re: Host file

mbigelow — Tue, 13 Jun 2017 19:44:49 GMT

Oh, if you are searching within CM for hosts to install the agent on, include all IPs for each hosts, which would be the ones you entered into the hosts for all hosts.

Re: Host file

csguna — Wed, 14 Jun 2017 01:34:21 GMT

if it is Vm as you wish since it is a static IP

Re: Host file

csguna — Wed, 14 Jun 2017 01:38:25 GMT

@mbigelow it come be a dumb question please bear with me .

is it mandatory to use fully qualified domain name ? because we dont not mention them in any of the hadoop configuration files. when it comes to networking not really my area. could you clarify

Re: Host file

mbigelow — Thu, 15 Jun 2017 03:58:56 GMT

@csguna no it isn't a requirement. They just all need to resolved the same on all hosts. For me it is about keeping it within enterprise standards and like I said I usually use DNS, which usually contains multiple zones. As a user of it, it find it cleaner to have and . use the FQDN versus just the hostname when it comes to the URLs (although alias can be used as well).

Re: Host file

mercedes012345 — Thu, 15 Jun 2017 07:35:51 GMT

Thanks,

Just a question, file /etc/sysconfig/network does not exist, should I create from scratch?

Re: Host file

csguna — Thu, 15 Jun 2017 08:46:44 GMT

@mbigelowThanks for the information , will follow the same and adher the standards.

Re: Host file

csguna — Thu, 15 Jun 2017 08:51:42 GMT

which operating system are you using ?

if you are using ubuntu

it should be

/etc/network/,

 /etc/network/interfaces

if you are using Centos do an ls command - below directory

/etc/sysconfig/

you should see one as network .

Re: Host file

MERCEDES0123 — Thu, 15 Jun 2017 09:00:20 GMT

I am using Ubuntu 14.04. I have a a folder with name /etc/network but no file inside. Should I directly create it? How should I name it?

Thanks a lot,

Kind regards,

Re: Host file

csguna — Thu, 15 Jun 2017 12:40:28 GMT

if you want to change the hostname then do either one of the following

sudo nano /etc/hostname

sudo vi  /etc/hostname

then restart the machine

to check your hostname after restart - open the terminal and type

hostname

To configure IP address do the following

sudo nano /etc/hosts

Re: Host file

MERCEDES0123 — Thu, 15 Jun 2017 13:23:19 GMT

I have already done this and after checked those file, I can see that the host has changed.

However, I can´t still access to cloudera manager web...is there something else I should do?

Thanks a lot,

Kind regards,