[SPARK-32518] CoarseGrainedSchedulerBackend.maxNumConcurrentTasks should consider all kinds of resources

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0
• Fix Version/s: 3.0.1, 3.1.0
• Component/s: Spark Core
• Assignee: wuyi
• Reporter: wuyi
• Created: 03/Aug/20 05:53
• Updated: 18/Aug/20 06:51
• Resolved: 06/Aug/20 05:40

Description

Currently, CoarseGrainedSchedulerBackend.maxNumConcurrentTasks only considers the CPU for the max concurrent tasks. This can cause the application to hang when a barrier stage requires extra custom resources but the cluster doesn't have enough corresponding resources. Because, without the checking for other custom resources in maxNumConcurrentTasks, the barrier stage can be submitted to the TaskSchedulerImpl. But the TaskSchedulerImpl can not launch tasks for the barrier stage due to the insufficient task slots calculated by calculateAvailableSlots(which does check all kinds of resources). 

Issue Links

• links to: [Github] Pull Request #29332 (Ngone51)
• links to: [Github] Pull Request #29332 (Ngone51)
• links to: [Github] Pull Request #29395 (Ngone51)