[AMBARI-25164] Rack "Config Refresh" behaviour is different in Ambari 2.6 and 2.7.3

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.3
• Fix Version/s: 2.8.0, 2.7.4
• Component/s: ambari-web
• Labels: pull-request-available
• Assignee: Andrii Tkach
• Reporter: Andrii Tkach
• Created: 21/Feb/19 09:57
• Updated: 27/Oct/22 06:33
• Resolved: 21/Feb/19 11:35

Description

In the new ambari-2.7.3 version, there is no way (via web ui) to generally refresh configs on a host . There is a way to refresh HDFS_CLIENT config on the Namenode host, but refreshing HDFS_CLIENT config does not refresh the topology_mappings.data file.

In Ambari 2.6.2: (During the "Refresh Configs")
When we refresh "Refresh Configs" then it refreshes all client configs which also includes HDFS and MapReduce2 config refresh. During the "Restart MapReduce2 Client" step it actually performs the "/etc/hadoop/conf/topology_mappings.data" file refresh with correct rack info which is updated via ambari ui.
Example :

2019-02-09 21:31:05,642 - File['/usr/hdp/2.6.5.0-292/hadoop/conf/configuration.xsl'] {'owner': 'hdfs', 'group': 'hadoop'}
2019-02-09 21:31:05,647 - File['/etc/hadoop/conf/topology_mappings.data'] {'owner': 'hdfs', 'content': Template('topology_mappings.data.j2'), 'only_if': 'test -d /etc/hadoop/conf', 'group': 'hadoop', 'mode': 0644}
2019-02-09 21:31:05,655 - File['/etc/hadoop/conf/topology_script.py'] {'content': StaticFile('P@.py'), 'only_if': 'test -d /etc/hadoop/conf', 'mode': 0755}

In Ambari 2.7.3: (During the "Refresh Configs")
Even after refreshing HDFS Client (AND) MapReduce Clients individually using "Refresh Configs" iwe do not see above kind of message. Also no changes happens inside the "/etc/hadoop/conf/topology_mappings.data" is not updated until we restart daemon components like DataNode. So the behavior of client config refresh seems to be slightly changed from ambari side.

Issue Links

• links to: GitHub PR#3412
• links to: GitHub Pull Request #2828