Question-6: Is there any dependency between the requirement of free memory and disk space with the number of nodes in the HDP cluster?

Answer: Yes, certainly it has. It depends how many nodes you have in your cluster and based on that you need memory and disk. In general for 1 node 1GB memory and 10GB disk space needed. Similarly for 100 node , 4GB memory and 100GB disk space. You need to check specific version to get the full detail.

Question-7: What is the ulimit and how it related to Ambari?

Answer: ulimit are the utility on Linux system to check, what all resources limits. For example we need to check number of open file descriptor supported you need to run below commands.

Check Soft limit using

ulimit  -Sn

Check hard limit using

ulimit -Hn

Question-8: How can i increase the open file limit descriptor values?

Answer: you can do using the command

ulimit -n 10000

In above command it will set the limit to 10000

Question-9: What is the FQDN?

Answer: You wanted to know the Fully Qualified name of the your linux host on which you would like to install the Ambari, so you could use the below command.

hostname -f

Question-10: Should we install Ambari on more than one host?

Answer: Yes, you should install the Apache Ambari at least on 3 nodes, if you are planning in production environment. Where one node will be master and another two node as slaves. So Ambari itself has its own cluster to manage the HDP cluster.