Chapter 2. Prerequisites
Meeting all prerequisites is essential for Ambari to know the cluster is in a healthy operating mode and can successfully manage the upgrade process. To perform an IOP migration using Ambari, your cluster must meet the following prerequisites.
- IOP Version
All hosts must have IOP version 4.2.0 or 4.2.5 installed.
- Disk Space
Be sure to have adequate space on
/usr/hdpfor the target HDP version. Each complete install of an HDP version will occupy about 2.5 GB of disk space.- Ambari Agent Heartbeats
All Ambari Agents must be communicating and heartbeating to the Ambari Server. Any hosts that are not heartbeating must be in Maintenance Mode.
- Host Maintenance Mode
The following two scenarios are checked:
Any hosts in Maintenance Mode must not be hosting any Service Master Components.
Any host in Maintenance Mode that is not hosting Master Components is allowed but you will receive a warning. You can proceed with your upgrade but these hosts will not be upgraded and before you can finalize the upgrade, you must delete the hosts from the cluster.
- Service Maintenance Mode
No Services can be in Maintenance Mode.
- Services Started
All Services must be started.
- Service Checks
All Service Checks must pass. Run Service Actions > Run Service Check on all services and remediate any issues, if necessary, before performing the IOP to HDP upgrade.
- Ranger Policy Export/Import DB Requirements
HDP-2.6 and higher versions include Ranger policy import/export. The minimum database requirements for this feature are as follows:
MariaDB: 10.1.16+
MySQL: 5.6.x+
Oracle: 11gR2+
PostgreSQL: 8.4+
MS SQL: 2008 R2+
- Big SQL
To upgrade Big SQL, you must have a user with the following attributes:
passwordless sudo access on all nodes of the cluster, including the Ambari server itself.
The ability to connect passwordlessly through ssh from the Ambari server to all Big SQL nodes. This user can be root. If the user is not root, the user name must be passed to the upgrade script with the -a option. The upgrade script must be run with root user privilege. This can be achieved by using the sudo command. If you have configured Ambari for non-root access (see Configuring Ambari for non-root access ), use the -a option with the user name created for that purpose.
Big SQL installation requires about 2 GB of free disk space on the /usr partition. The upgrade process requires about 4 GB of free disk space on the root partition. This space is used temporarily by the upgrade process. It is released when the upgrade is complete.
You must disable Big SQL high availability before performing an upgrade.
Ambari configuration groups are not supported for the Big SQL service. The upgrade script produces a warning message if you use configuration groups. If you override the warning, you must validate that the configuration of all nodes in all configuration groups is updated as part of the upgrade. It is recommended that you remove all configuration groups before performing an upgrade.
You must disable Yarn and Slider support for Big SQL before performing an upgrade.