Prepare the Environment

To deploy your HDP instance, you must prepare your deployment environment:

Enable NTP on Your Cluster

The clocks of all the nodes in your cluster must be synchronized. If your system does not have access to the Internet, you should set up a master node as an NTP xserver to achieve this synchronization.

Use the following instructions to enable NTP for your cluster:

Configure NTP clients by executing the following command on each node in your cluster:
- For RHEL/CentOS/Oracle Linux 6:
  yum install ntp
- For RHEL/CentOS/Oracle Linux 7:
1. Configure the NTP clients:
  yum install ntp
2. Enable the service:
  systemctl enable ntpd
3. Start NTPD:
  systemctl start ntpd
- For SLES:
  zypper install ntp
- For Ubuntu and Debian:
  apt-get install ntp
Enable the service by executing the following command on each node in your cluster:
- For RHEL/CentOS/Oracle Linux:
  chkconfig ntpd on
- For SLES, Ubuntu, and Debian:
  chkconfig ntp on
Start the NTP. Execute the following command on all the nodes in your cluster.
- For RHEL/CentOS/Oracle Linux:
  /etc/init.d/ntpd start
- For SLES:
  /etc/init.d/ntp start
- For Ubuntu and Debian:
  /etc/init.d/ntp start
If you want to use an existing NTP server as the X server in your environment, complete the following steps:
1. Configure the firewall on the local NTP server to enable UDP input traffic on Port 123 and replace 192.168.1.0/24 with the IP addresses in the cluster, as shown in the following example using RHEL hosts:
  # iptables -A RH-Firewall-1-INPUT -s 192.168.1.0/24 -m state --state NEW -p udp --dport 123 -j ACCEPT
2. Save and restart iptables. Execute the following command on all the nodes in your cluster:
  # service iptables save
  # service iptables restart
3. Finally, configure clients to use the local NTP server. Edit the /etc/ntp.conf file and add the following line:
  server $LOCAL_SERVER_IP OR HOSTNAME

Disable SELinux

The Security-Enhanced (SE) Linux feature should be disabled during the installation process.

Check the state of SELinux. On all the host machines, execute the following command:
getenforce
If the command returns "disabled" or "permissive" as the response, no further actions are required. If the result is enabled, proceed to Step 2.
Disable SELinux either temporarily for each session or permanently.
- Disable SELinux temporarily by executing the following command:
  setenforce 0
- Disable SELinux permanently in the /etc/sysconfig/selinux file by changing the value of the SELINUX field to permissive or disabled. Restart your system.

Disable IPTables

Because certain ports must be open and available during installation, you should temporarily disable iptables. If the security protocols at your installation do not allow you to disable iptables, you can proceed with them on if all of the relevant ports are open and available; otherwise, cluster installation fails. See "Configuring Ports" in the HDP Reference Guide for more information.

On all RHEL/CentOS 6 host machines, execute the following commands to disable iptables:
chkconfig iptables off
service iptables stop
Restart iptables after your setup is complete.
On RHEL/CENTOS 7 host machines, execute the following commands to disable firewalld:
systemctl stop firewalld
systemctl mask firewalld
Restart firewalld after your setup is complete.
On Ubuntu and Debian host machines, execute the following command to disable iptables:
service ufw stop
Restart iptables after your setup is complete.

	Important
	If you leave iptables enabled and do not set up the necessary ports, the cluster installation fails.