def _getMetricCollectionTimeSliceForAutostackMetric(cls, period):
""" Determine metric data collection time range, truncated at the time
indicated by the current time window.
:param period: Metric period in seconds; must be multiple of 60
:type period: integer
:returns: time range for collecting metrics for the current time window.
:rtype: htm.it.app.runtime.aggregator_utils.TimeRange
"""
now = datetime.utcnow().replace(second=0, microsecond=0)
endTime = now - timedelta(
seconds=cloudwatch_utils.getMetricCollectionBackoffSeconds(period))
startTime = endTime - timedelta(seconds=period)
return TimeRange(start=startTime, end=endTime)
def testNormalizeMetricCollectionTimeRangeWithFixedStartAndDefaultEnd(self):
fakeUtcnow = datetime(2015, 11, 1, 12, 0, 0)
fixedStartTime = datetime(2015, 11, 1, 9, 0, 0)
period = 300
datetimePatch = patch("datetime.datetime",
new=Mock(wraps=datetime,
utcnow=Mock(side_effect=[fakeUtcnow])))
with datetimePatch as datetimeMock:
rangeStart, rangeEnd = (
cloudwatch_utils.normalizeMetricCollectionTimeRange(
startTime=fixedStartTime,
endTime=None,
period=period)
)
# Fixed start should be honored
self.assertEqual(rangeStart, fixedStartTime)
# Default end should be at an integral number of periods, not to exceed
# the empirically-determine backoff from now and also limited by
# CLOUDWATCH_MAX_DATA_RECORDS
self.assertEqual(datetimeMock.utcnow.call_count, 1)
rangeEndLimit = (
fakeUtcnow -
timedelta(seconds=cloudwatch_utils.getMetricCollectionBackoffSeconds(
period))
)
expectedRangeEnd = min(
(fixedStartTime +
timedelta(seconds=(rangeEndLimit - fixedStartTime).total_seconds() //
period * period)),
(fixedStartTime +
timedelta(seconds=cloudwatch_utils.CLOUDWATCH_MAX_DATA_RECORDS * period))
)
self.assertEqual(rangeEnd, expectedRangeEnd)
