[FLINK-23510] add a new metric to show the max usage of inputExclusiveBuffer for each inputChannel

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: Runtime / Metrics
• Assignee: Unassigned
• Reporter: zoucao
• Created: 27/Jul/21 07:01
• Updated: 27/Jul/21 07:01

Description

Now, the 'inPoolUsage' and 'inputExclusiveBuffersUsage' describe the overall situation of a task's network usage. Sometimes, when the back pressure was present, I found the value of 'inPoolUsage' or 'inputExclusiveBuffersUsage' were very low, beacuse they were averaged by the input channel whose buffer usage is low. I propose to add a new metric for each task to record the maximum buffer usage of all input channels belonged to this task.