nicktelford commented on code in PR #16041: URL: https://github.com/apache/kafka/pull/16041#discussion_r1613568734
########## streams/src/test/java/org/apache/kafka/streams/state/internals/MeteredKeyValueStoreTest.java: ########## @@ -490,6 +490,31 @@ public void shouldTimeIteratorDuration() { assertThat((double) iteratorDurationMaxMetric.metricValue(), equalTo(3.0 * TimeUnit.MILLISECONDS.toNanos(1))); } + @Test + public void shouldTrackOldestOpenIteratorTimestamp() { + when(inner.all()).thenReturn(KeyValueIterators.emptyIterator()); + init(); + + final KafkaMetric oldestIteratorTimestampMetric = metric("oldest-iterator-open-since-ms"); + assertThat(oldestIteratorTimestampMetric, not(nullValue())); + + assertThat(oldestIteratorTimestampMetric.metricValue(), nullValue()); + + try (final KeyValueIterator<String, String> first = metered.all()) { + final long oldestTimestamp = mockTime.milliseconds(); + assertThat((Long) oldestIteratorTimestampMetric.metricValue(), equalTo(oldestTimestamp)); + mockTime.sleep(100); + + // open a second iterator before closing the first to test that we still produce the first iterator's timestamp + try (final KeyValueIterator<String, String> second = metered.all()) { + assertThat((Long) oldestIteratorTimestampMetric.metricValue(), equalTo(oldestTimestamp)); + mockTime.sleep(100); + } Review Comment: I've updated the tests with your first suggestion. I didn't go further as I feel that this case is already adequately tested. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org