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Prerequisites

To deploy Unravel, first ensure that your environment meets these requirements.

Important

You must use an independent host for the Unravel server.

This host must:

  • Be managed by Ambari.

  • Have Hadoop clients pre-installed.

  • Have no other Hadoop service or third-party applications installed.

  • Accessible to only Hadoop and Unravel Admins.

Platform

Each version of Unravel has specific platform requirements. Check Unravel's HDP compatibility matrix to confirm that your cluster meets the requirements for the version of Unravel that you're installing. Your cluster must be deployed using Ambari.

Sizing

Use Ambari Web UI to allocate a new node in your cluster. This node will be the host machine for Unravel. Provision it as described below.

Software

On the Unravel host, confirm the following configuration:

  • All default clients are running:

    hdp-new-node.png
  • If the Unravel host is running Red Hat Enterprise Linux (RHEL) 6.x, set its bootstrap.system_call_filter to false in elasticsearch.yml:

    boostrap.system_call_filter: false
  • libaio.x86_64 is installed.

  • If you're installing Unravel version 4.5.0.0, set SELINUX to permissive or disabled in /etc/sysconfig/selinux.

    If you're installing Unravel version 4.5.0.1+, SELINUX can be set to enabled.

  • PATH includes the path to the HDFS+Hive+YARN+Spark client/gateway, Hadoop commands, and Hive commands.

  • Zookeeper is not installed.

Permissions

This is a list of permissions you'll need to grant to the Unravel username after you install the Unravel Server RPM. We'll walk you through setting these up later.

The only permission you need to set up right now on the Unravel host is root access or "sudo root" permission in order to install the Unravel Server RPM.

  • If you're using Kerberos, you'll need to create a principal and keytab for Unravel daemons to use to access certain HDFS resources.

  • Unravel needs access to the YARN resource manager's REST API (so that the principal can determine which resource manager is active).

  • Unravel needs access to the JDBC access to the Hive metastore. Read-only access is sufficient.

  • If you plan to use Unravel's move or kill auto actions, the Unravel username needs to be added to YARN's yarn.admin.acl property.

  • Unravel needs read-only access to the Application Timeline Server (ATS).

Network