MergeRollupTaskGenerator incorrectly calculates earliest start time of in_progress segments

[sajjad-moradi]

For realtime table, MergeRollup task is intended to not process segments with start time later than the earliest start time of all in progress segments, but the code is not calculating it correctly. The if condition in the following part of the code is alway false because totalDocs and startTimeMs are both -1 for consuming segments. This leads to incorrectly calculate earliestStartTime to Long.MAX_VALUE:

pinot/pinot-plugins/pinot-minion-tasks/pinot-minion-builtin-tasks/src/main/java/org/apache/pinot/plugin/minion/tasks/mergerollup/MergeRollupTaskGenerator.java

Lines 568 to 575 in 9c8ab8f

	long earliestStartTimeMsOfInProgressSegments = Long.MAX_VALUE;
	for (SegmentZKMetadata segmentZKMetadata : allSegments) {
	if (!segmentZKMetadata.getStatus().isCompleted()
	&& segmentZKMetadata.getTotalDocs() > 0
	&& segmentZKMetadata.getStartTimeMs() < earliestStartTimeMsOfInProgressSegments) {
	earliestStartTimeMsOfInProgressSegments = segmentZKMetadata.getStartTimeMs();
	}
	}

[kate-yq]

I'll work on this. Thx.