[SPARK-42206] Omit "Task Executor Metrics" field in JsonProtocol output if values are all zero

• Type: Improvement
• Status: In Progress
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.0.0
• Component/s: Spark Core
• Assignee: Josh Rosen
• Reporter: Josh Rosen
• Created: 27/Jan/23 00:40
• Updated: 27/Jan/23 08:52

Description

SPARK-26329 added "Task Executor Metrics" to JsonProtocol SparkListenerTaskEnd JSON. With the default `spark.executor.metrics.pollingInterval = 0` configuration these metric values are only updated when heartbeats occur. If a task launches and finishes between executor heartbeats then all of these metric values will be zero. For jobs with large numbers of short tasks, this contributes to significant event log bloat.

JsonProtocol already knows how to handle the absence of the "Task Executor Metrics" field, so I think it's safe for us to omit this field when all values are zero.

Issue Links

• links to: [Github] Pull Request #39770 (JoshRosen)
• links to: [Github] Pull Request #39770 (JoshRosen)