[YARN-10014] Refactor boolean flag based approach in SchedConfCLI#run

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Oleg Bonar
• Reporter: Prabhu Joseph
• Created: 06/Dec/19 06:31
• Updated: 03/Jan/20 09:17

Description

Boolean-flag based approach in org.apache.hadoop.yarn.client.cli.SchedConfCLI#run:
Everything is controlled with boolean flags here.
The flag hasOption is set to true in each of the if-clauses just to make the condition below the hasOption-conditions happy. The flag is set to true even for parameter that don't have an option (like 'getConf') at all, this is very misleading and hard to understand for the first read.

Need below refactoring:
a. Eliminates the hasOption boolean flag
b. Where an option is misused, fail-fast: Have a method that contains this code and call it for every option, in-place:

if (!hasOption) {
 System.err.println("Invalid Command Usage: ");
 printUsage();
 return -1;
 }

c. Remove the boolean flags: format and getConf as well. These are unnecessary.

cc snemeth

Issue Links

• is related to: YARN-9781 SchedConfCli to get current stored scheduler configuration
• links to: GitHub Pull Request #1746