[BEAM-11435] Reuse already set timers instead of recreating them in Flink Streaming Runner

• Type: Bug
• Status: Resolved
• Priority: P1
• Resolution: Fixed
• Affects Version/s: 2.23.0, 2.24.0, 2.25.0
• Fix Version/s: 2.27.0
• Component/s: runner-flink
• Assignee: David Morávek
• Reporter: David Morávek
• Created: 10/Dec/20 11:35
• Updated: 10/Dec/20 21:03
• Resolved: 10/Dec/20 21:03

Description

When we re-set a timer, new timer goes trough following life-cycle:
1) Find previously set timer with the same id
2) Cancel any previously set timer with the same id
3) Set a new timer

We can skip 2) and 3), if the new timer is the same as previously set timer. There should be a great performance impact on GC timers, especially with RocksDB backend, where 2) and 3) are expensive operations.

Issue Links

• links to: GitHub Pull Request #13522