[FLINK-15629] Remove LegacyScheduler class and the consequently unused codes after this removal

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.11.0
• Fix Version/s: 1.11.0
• Component/s: Runtime / Coordination
• Labels: pull-request-available
• Release Note: Flink no longer supports the legacy scheduler. Hence, setting `jobmanager.scheduler: legacy` will no longer work and fail with an `IllegalArgumentException`. The only valid option for `jobmanager.scheduler` is the default value `ng`.
• Assignee: Zhu Zhu
• Reporter: Zhu Zhu
• Created: 17/Jan/20 08:56
• Updated: 16/Oct/20 10:33
• Resolved: 16/May/20 13:23

Description

This task is to remove the LegacyScheduler class and the consequently unused codes after this removal.
Note that the scheduling/failover logics in ExecutionGraph would be removed in a separate task.

Issue Links

• blocks: FLINK-15813 Set default value of jobmanager.execution.failover-strategy to region
• is duplicated by: FLINK-17738 Remove legacy scheduler option
• links to: GitHub Pull Request #10883