[AMBARI-24981] JournalNode may fail to start due to unreadable config file

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.8.0
• Component/s: ambari-agent
• Labels: pull-request-available
• Assignee: Attila Doroszlai
• Reporter: Attila Doroszlai
• Created: 01/Dec/18 16:53
• Updated: 26/Feb/19 17:54
• Resolved: 05/Feb/19 14:53

Description

During startup, JournalNode reads config files that belong to YARN, not HDFS (eg. yarn-site.xml), if they are present in the Hadoop config dir.

Ambari's File() provider creates files at the final location, then sets metadata (ownership and permissions). This makes the file visible to other processes with possibly the wrong metadata.

If agent-side parallel execution is enabled, JournalNode may be started concurrently with some YARN component. JournalNode may encounter a config file that it cannot read, because the file's permissions and owner are still 640 and root, respectively, which causes it to shutdown:

ERROR conf.Configuration (Configuration.java:loadResource(2999)) - error parsing conf yarn-site.xml
java.io.FileNotFoundException: /etc/hadoop/conf/yarn-site.xml (Permission denied)

Issue Links

• links to: GitHub Pull Request #2679