[KYLIN-3238] Fix NPE when CubeInstance.getLatestReadySegment() returns null

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Fix Version/s: v3.1.0
• Assignee: Zhong Yanghong
• Reporter: Zhong Yanghong
• Created: 05/Feb/18 07:45
• Updated: 31/Jul/20 12:02
• Resolved: 22/Jun/20 03:04

Description

Currently we suppose if a cube is in READY status, there should exist READY segments. Then when this kind of cube is selected as a candidate for a query, neither getLatestReadySegment in CubeInstance will return null, nor cube.getSegments().get(0) will throw IndexOutOfBoundsException.

However, currently we allow to delete segments by REST API when cube is in READY status, which I think it's not reasonable. To deal with this issue, I propose not to allow segment deletion by REST API when its cube is in READY status.