[AURON #2189] Periodically publish native metrics for long-running Fl…

[qingfei1994]

…ink tasks

Which issue does this PR close?

Closes #2189

Rationale for this change

Native DataFusion metrics were only published to MetricNode when the native runtime finalized. Spark batch tasks hit that path; long-running Flink tasks (Kafka source) do not, so Flink counters never moved after #2186 wired add to Flink.

What changes are included in this PR?

• Periodic native metric publish on a tokio interval, sending positive deltas so incremental MetricNode.add does not double-count.
• Config auron.metrics.update.interval.ms (default 1000; 0 = finalize-only).
• FlinkMetricNode.fromPlan so Kafka (including fused Project[Filter[KafkaScan]]) and Calc share a plan-shaped metric tree for getChild(i).

Are there any user-facing changes?

Operators can set auron.metrics.update.interval.ms (default 1000ms). Spark SQL metrics may update during the job as a side effect of the same ticker.

How was this patch tested?

• cargo test -p auron metrics
• Maven: FlinkMetricNodeFromPlanTest, AuronKafkaSourceFunctionMergeTest, FlinkMetricNodeTest, AuronAdaptorTest

Was this patch authored or co-authored using generative AI tooling?

• Yes
• No

If yes, include: Generated-by: Cursor Grok 4.6

ASF guidance: https://www.apache.org/legal/generative-tooling.html

[Tartarus0zm]

hi @richox could you please help review this PR when you get a chance? Thanks!

[richox]

Thanks for implementing scheduled metric reporting in Auron.

Since this feature is currently only needed for Flink and not for Spark, I suggest adding a configuration item (e.g., auron.metrics.ticker.enabled) that is disabled by default and only enabled for Flink. This keeps the behavior opt-in and avoids unnecessary overhead for other engines.

Could you update the PR accordingly?

[qingfei1994]

@richox I use a new configuration "auron.metrics.update.enabled", which is disabled by default and only when "flink.auron.metrics.update.enabled" = true and "flink.auron.metrics.update.interval.ms">0 will triggering the report metrics feature.