[Bug]: [Dataflow] [Java] MetricReport StringSet causes ClassCastException

[lukemin89]

What happened?

Issue: ClassCastException. Seems like Object set field in com.google.api.services.dataflow.model.MetricUpdate is List type, but trying to cast as Set causes the issue.
Version: 2.58.1
Language: Java

It causes MetricResults.allMetrics() fails, preventing us from scanning the metric results.

[2024-10-02, 02:36:50 KST] {pod.py:778} INFO - Container logs: Caused by: java.lang.ClassCastException: class java.util.ArrayList cannot be cast to class java.util.Set (java.util.ArrayList and java.util.Set are in module java.base of loader 'bootstrap')
[2024-10-02, 02:36:50 KST] {pod.py:778} INFO - Container logs: 	at org.apache.beam.runners.dataflow.DataflowMetrics$DataflowMetricResultExtractor.getStringSetValue(DataflowMetrics.java:194)
[2024-10-02, 02:36:50 KST] {pod.py:778} INFO - Container logs: 	at org.apache.beam.runners.dataflow.DataflowMetrics$DataflowMetricResultExtractor.addMetricResult(DataflowMetrics.java:168)
[2024-10-02, 02:36:50 KST] {pod.py:778} INFO - Container logs: 	at org.apache.beam.runners.dataflow.DataflowMetrics$DataflowMetricQueryResultsFactory.build(DataflowMetrics.java:382)
[2024-10-02, 02:36:50 KST] {pod.py:778} INFO - Container logs: 	at org.apache.beam.runners.dataflow.DataflowMetrics.populateMetricQueryResults(DataflowMetrics.java:96)
[2024-10-02, 02:36:50 KST] {pod.py:778} INFO - Container logs: 	at org.apache.beam.runners.dataflow.DataflowMetrics.queryMetrics(DataflowMetrics.java:114)
[2024-10-02, 02:36:50 KST] {pod.py:778} INFO - Container logs: 	at org.apache.beam.sdk.metrics.MetricResults.allMetrics(MetricResults.java:61)
[2024-10-02, 02:36:50 KST] {pod.py:778} INFO - Container logs: 	at ...MetricLogger.streamMetrics(MetricLogger.java:35)

Issue Priority

Priority: 1 (data loss / total loss of function)

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[lukemin89]

I see fixed in 2.59.0

[Abacn]

yeah, it was fixed as part of #32002 that PR was reverting some code that temporarily disable stringset metrics, then during testing I saw ClassCastException and I assumed it was a bug in the original change, and didn't realize it affected 2.58.0