Apache Ambari Release Notes
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New Features

The Ambari 2.5.1 release is a maintenance release that includes no new features.

Ambari 2.5 contains the following features and improvements:

Table 1.1. Core Ambari



Add/Remove Journal Nodes


Easily add additional JournalNodes, or remove and move existing JournalNodes for installations where NameNode HA is enabled.

Service Auto-Start


Configure specific components to start automatically if the host they are on reboots, or if the process exits abnormally.

Configuration Change Communication


A new pop-up has been added to more clearly communicate the impact on configuration for common administrative operations such as changing individual configurations, adding components, remove components, moving master services, and enabling HA.

HDFS TopN User & Operation Visualization


Quickly understand the most frequent operations being performed on the NameNode, and more importantly who’s performing those operations.

Download All Client Configurations


Download client configurations for all components installed in the cluster with a single-click.



The default SNMP Alert Notification now sends SNMP traps using an Ambari-specific MIB.

DB Inconsistency Self-Healing


Common database inconsitencies are now automatically fixed when issues are detected on Ambari Server startup.

Log Search TP Update


Updates to the Log Search component to improve security, stability, and performance. This capability is currently Tech Preview.

Ignore Host Pre-Check when Adding a Host


Added the ability to disable host pre-checks when adding hosts after the cluster has been installed.

Post User-creation Script Hook


Create user home directories in HDFS when users are created in the Ambari DB, or sync'd with LDAP. This feature is disabled by default and can easily be enabled after installation of the Ambari Server.

Password Credential Store Management


For those components that support storing passwords in credential stores, such as Ranger, Hive, and Oozie, passwords are now stored in credential stores by default for fresh installs.

Port Preserving HS2 Rolling Upgrade


During the Rolling Upgrade, the Hive Server 2 port will not be changed. Hive downtime is still incurred during the upgrade.

Ambari SPNEGO Support


Ambari now supports API authentication using SPNEGO.

SmartSense Mandatory Installation


For new installs, SmartSense will be installed by default. Entering your Hortonworks SmartSense ID is still required to activate SmartSense. No bundles will be captured and sent until the a valid SmartSense ID is entered.

Grafana Dashboard for Ambari


New Grafana dashboards for visualizing the performance metrics of the Ambari Server itself are now available.

ZK ACL and SASL Configuration


ZooKeeper ACL's are now optimally configured for tighter security control and SASL is configured for fresh cluster installs.

Simplified Log Rotation Configuration


It's now easy to configure the number and size of backup files for each component using Log4j. For customers that are upgrading from previous versions of Ambari, there is a post-upgrade step required to fully enable this capability.

AMS Collector High Availability


The Ambari Metrics System now supports multiple Metrics Collector instances, providing High Availability and better scalability. This capability is currently Tech Preview.

More Information

SmartSense User Guide