[AMBARI-24768] Load Upgrade Checks Dynamically From Stacks

• Type: Task
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 2.8.0
• Fix Version/s: 2.8.0
• Labels: pull-request-available
• Epic Link: Ambari 2.8 Stack Upgrades
• Assignee: Jonathan Hurley
• Reporter: Jonathan Hurley
• Created: 12/Oct/18 14:21
• Updated: 16/Oct/18 15:51
• Resolved: 16/Oct/18 15:51

Description

Stack-provided upgrade checks need to be loaded from a provided JAR when Ambari Server starts up. Currently, upgrade checks are loaded synchronously, scanning the entire classpath for classes matching UpgradeCheck in the package org.apache.ambari.server.checks. This can be extremely slow and cause Ambari Server to fail to start within a reasonable amount of time. The proposed changes for this issue are as follows:

• Move to an asynchronous model for scanning the classpath for instances of UpgradeCheck
• Allow stacks to provide their own plugin directory & JAR for loading SPI implementations of UpgradeCheck

Issue Links

• links to: GitHub Pull Request #2451