[MINOR] move metrics implementation to hudi-common

[jintaoguan]

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• 9921501 Azure: FAILURE

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[garyli1019]

Hi @jintaoguan , thanks for your contribution. Would you describe the initiative of this PR? I couldn't see the benefit of moving the metric to common.

[jintaoguan]

@garyli1019 Currently all metrics-related implementations are in hudi-client-common. But I want to emit some metrics for hudi-hadoop-mr which only depends on hudi-common. Moving metrics to hudi-common will allow all modules like hudi-hadoop-mr or hudi-hive-sync to access the metrics-related implementation.

[garyli1019]

@jintaoguan I see, this is not a minor change. Would you create a Jira ticket and add the description there?
I am afraid this will make common too heavy. Maybe we can make hudi-metric an independent module? @xushiyan thoughts?

[jintaoguan]

@garyli1019 We might need to think about the plan for moving the implementations of metrics. So I will just abandon this PR for now. Thank you for reviewing.