Can Ambari server and agent run on same host ?

[#1]

Hello,

I am a newbie to horton and ambari. I am trying to make a 2 node hadoop cluster with physical server.

I am thinking of using Ambari to do provisioning. However since i only have 2 nodes, can i use Ambari server and ambari-agent on same node?

Right now if i do that, ambari-agent fails to startup and gives java unknown host exception . when i used FQDN

Thanks

[#2]

@Majid Ali Syed Amjad Ali Sayed

I noticed on the screenshot you attached that started manually the agent on krplhadoop02 (see attached file)krplhadoop-ambari-agent.jpg

The agent will be installed by the during the Ambari server installation ! Please clean up that host and relaunch the Ambari install

My biggest worry was the passwordless login configuration between the servers in the cluster ,so I had this procedure for you

The assumption here is that you are running the Ambari installation as root

1.Delete the directory .ssh in roots home directory on krplhadoop.kaimrc

[root@krplhadoop.kaimrc]#ssh-keygen

Accept the defaults

[root@krplhadoop.kaimrc]# ls authorized_keys id_rsa id_rsa.pub known_hosts

The first one contains the private key, the second one contains the public key for user root.

2. Now run the command

[root@krplhadoop.kaimrc]#cat /root/.ssh/id_rsa.pub >> /root/.ssh/authorized_keys

this will add the contents of the root’s file id_rsa.pub to a file authorized_keys.

Therefore, if a user will connect to this machine by SSH and will specify the correct private key, this machine will look up into authorized_keys and will know that this is root.

3. Copy this file authorized_keys as root to krplhadoop2.kaimrc in /root/.ssh directory Also check the permissions on the .ssh directory, id.rsa,authorized_keys and id_rsa.pub keys

4. Configure Database for ambari assuming you are using MySQL and don't forget to yum install mysql-connector-java and the appropriate permissions 644

5. Pre-load the Ambari database schema into your MySQL database then and pre-load the Ambari database schema into your MySQL database

6. [root@krplhadoop.kaimrc]# yum install ambari-server

7. [root@krplhadoop.kaimrc]#ambari-server setup /* output Ambari Server 'setup' completed successfully.*/

8. [root@krplhadoop.kaimrc]# Start the server #ambari-server start

[#3]

@Majid Ali Syed Amjad Ali Sayed

Are you still stuck ? If you could you attach your ambari log here.

[#4]

@Majid Ali Syed Amjad Ali Sayed

I have 2 node cluster running in my environment.

If you have not fixed this then do this "Assuming that you are just doing this in your lab"

[root@phdns01 ~]# ambari-server reset

Using python /usr/bin/python2

Resetting ambari-server

**** WARNING **** You are about to reset and clear the Ambari Server database. This will remove all cluster host and configuration information from the database. You will be required to re-configure the Ambari server and re-run the cluster wizard.

Are you SURE you want to perform the reset [yes/no] (no)? yes

Confirm server reset [yes/no](no)? yes

Resetting the Server database...

Connecting to local database...done.

WARNING: Non critical error in DDL, use --verbose for more information

Ambari Server 'reset' completed with warnings.

Once it's done then you can try to reinstall the cluster.

Your /etc/hosts looks fine.

[#5]

you should install ambari-server and ambari-agent on the first node wich you want to install hdfs service for example .

the other nodes install ambari-agent only .

dont forget to change (ambari-agent.ini ) hostname

and the hosts file with (ip and hostname of all machines.