Details
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Bug
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Status: Resolved
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Low
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Resolution: Not A Problem
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3.0.26, 3.11.12, 4.0.1, 4.1-alpha1, 4.1
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None
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Low
Description
We noticed an increase in read latency after upgrading to 3.x, specifically for requests with CL>ONE. It turns out the read latency metric is being doubly updated for digest calculations. This code (https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/db/partitions/UnfilteredPartitionIterators.java#L243) makes an improper copy of an iterator that's wrapped by MetricRecording, whose onClose() records the latency of the execution.