[AMBARI-22665] Livy2 Does Not Start On HDP 2.6.0 to 2.6.3

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.6.1
• Fix Version/s: 2.6.2
• Assignee: Jonathan Hurley
• Reporter: Jonathan Hurley
• Created: 18/Dec/17 17:22
• Updated: 18/Jan/18 18:26
• Resolved: 22/Dec/17 14:51

Description

Livy2 was added as a component in HDP 2.6, starting with HDP 2.6.0.0. However, there was no stack-select or conf-select support for some reason. stack-select and conf-select was built into HDP 2.6.4.0.

Ambari added livy2 as a known conf-select to the HDP 2.6 stack. On deployments of HDP 2.6.4+, this is correct and the server can properly start.

However, when using Ambari to deploy Livy2 on HDP 2.6.0 - 2.6.3, we see the following:

2017-12-18 14:53:52,711 - Checking to see which directories will be created for livy2 on version 2.6.0.0-334
2017-12-18 14:53:52,711 - call[('ambari-python-wrap', '/usr/bin/conf-select', 'dry-run-create', '--package', 'livy2', '--stack-version', '2.6.0.0-334', '--conf-version', '0')] {'logoutput': False, 'sudo': True, 'quiet': False, 'stderr': -1}
2017-12-18 14:53:52,734 - call returned (1, 'livy2 not installed or incorrect package name', '')
2017-12-18 14:53:52,735 - Creating /etc/livy2/2.6.0.0-334/0 if it does not exist
2017-12-18 14:53:52,736 - call[('ambari-python-wrap', '/usr/bin/conf-select', 'create-conf-dir', '--package', 'livy2', '--stack-version', '2.6.0.0-334', '--conf-version', '0')] {'logoutput': False, 'sudo': True, 'quiet': False, 'stderr': -1}
2017-12-18 14:53:52,765 - call returned (1, 'livy2 not installed or incorrect package name', '')
2017-12-18 14:53:52,766 - checked_call[('ambari-python-wrap', '/usr/bin/conf-select', 'set-conf-dir', '--package', 'livy2', '--stack-version', '2.6.0.0-334', '--conf-version', '0')] {'logoutput': False, 'sudo': True, 'quiet': False}
2017-12-18 14:53:52,795 - Could not select the directory for package livy2. Error: Execution of 'ambari-python-wrap /usr/bin/conf-select set-conf-dir --package livy2 --stack-version 2.6.0.0-334 --conf-version 0' returned 1. livy2 not installed or incorrect package name
2017-12-18 14:53:52,796 - /etc/livy2/conf is a directory - it must be converted into a symlink

Essentially, Ambari is trying to setup the configuration pointers, but it is ignoring the dry-run result code. At the end of the day, we end up with Livy2 not starting b/c we're manipulated the configuration pointers, but conf-select failed to properly create a versioned configuration directory.

The solution is to check the dry-run result code and do nothing if conf-select doesn't support the package.