[FLINK-22438] add numRecordsOut metric for Async IO

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.11.3, 1.12.2, 1.13.0
• Fix Version/s: 1.14.0, 1.13.1, 1.12.4
• Component/s: Runtime / Metrics, Runtime / Task
• Labels: pull-request-available
• Assignee: Zhengqi Zhang
• Reporter: Zhengqi Zhang
• Created: 23/Apr/21 17:07
• Updated: 28/May/21 11:06
• Resolved: 29/Apr/21 09:29

Description

In Flink WebUI,there is no numRecordsOut metric,and the class AsyncWaitOperator did't have this metric in fact.Other operators have this metric, which makes it difficult to monitor Async IO operator and can cause confusion for users.

I think we can directly  use the wrapping output class CountingOutput to update numRecordsOut metric.CountingOutput is used in super class of AsyncWaitOperator(AbstractStreamOperator).

Here is my commit,And I have run a test, it work.

my  commit

Issue Links

• is caused by: FLINK-14044 Reducing synchronization in AsyncWaitOperator
• links to: GitHub Pull Request #15791