def __ensure_provisioning_reads(table_name):
""" Ensure that provisioning is correct
:type table_name: str
:param table_name: Name of the DynamoDB table
:returns: (bool, int) -- update_needed, updated_read_units
"""
update_needed = False
updated_read_units = statistics.get_provisioned_read_units(table_name)
consumed_read_units_percent = \
statistics.get_consumed_read_units_percent(table_name)
if (consumed_read_units_percent == 0 and not
get_table_option(table_name, 'allow_scaling_down_reads_on_0_percent')):
logger.info(
'{0} - Scaling down reads is not done when usage is at 0%'.format(
table_name))
elif (consumed_read_units_percent >=
get_table_option(table_name, 'reads_upper_threshold')):
if get_table_option(table_name, 'increase_reads_unit') == 'percent':
updated_provisioning = calculators.increase_reads_in_percent(
table_name,
updated_read_units,
get_table_option(table_name, 'increase_reads_with'))
else:
updated_provisioning = calculators.increase_reads_in_units(
table_name,
updated_read_units,
get_table_option(table_name, 'increase_reads_with'))
update_needed = True
updated_read_units = updated_provisioning
elif (consumed_read_units_percent <=
get_table_option(table_name, 'reads_lower_threshold')):
if get_table_option(table_name, 'decrease_reads_unit') == 'percent':
updated_provisioning = calculators.decrease_reads_in_percent(
table_name,
updated_read_units,
get_table_option(table_name, 'decrease_reads_with'))
else:
updated_provisioning = calculators.decrease_reads_in_units(
table_name,
updated_read_units,
get_table_option(table_name, 'decrease_reads_with'))
update_needed = True
updated_read_units = updated_provisioning
return update_needed, int(updated_read_units)
def test_decrease_reads_in_percent_more_than_100_percent(self):
""" Handle decreases of more that 100% """
result = calculators.decrease_reads_in_percent(20, 120, 1, 'test')
self.assertEqual(result, 1)
def test_decrease_reads_in_percent_hit_min_value(self):
""" Check that min values are honoured """
result = calculators.decrease_reads_in_percent(20, 50, 15, 'test')
self.assertEqual(result, 15)
def test_decrease_reads_in_percent(self):
""" Ensure that a regular decrease works """
result = calculators.decrease_reads_in_percent(200, 90, 1, 'test')
self.assertEqual(result, 20)
def test_decrease_reads_in_percent(self):
""" Ensure that a regular decrease works """
result = calculators.decrease_reads_in_percent(200, 90, 1, 'test')
self.assertEqual(result, 20)
def test_decrease_reads_in_percent_more_than_100_percent(self):
""" Handle decreases of more that 100% """
result = calculators.decrease_reads_in_percent(20, 120, 1, 'test')
self.assertEqual(result, 1)
def test_decrease_reads_in_percent_hit_min_value(self):
""" Check that min values are honoured """
result = calculators.decrease_reads_in_percent(20, 50, 15, 'test')
self.assertEqual(result, 15)
def __ensure_provisioning_reads(table_name, key_name):
""" Ensure that provisioning is correct
:type table_name: str
:param table_name: Name of the DynamoDB table
:type key_name: str
:param key_name: Configuration option key name
:returns: (bool, int) -- update_needed, updated_read_units
"""
update_needed = False
updated_read_units = statistics.get_provisioned_read_units(table_name)
consumed_read_units_percent = \
statistics.get_consumed_read_units_percent(table_name)
if (consumed_read_units_percent == 0 and not
get_table_option(key_name, 'allow_scaling_down_reads_on_0_percent')):
logger.info(
'{0} - Scaling down reads is not done when usage is at 0%'.format(
table_name))
elif (consumed_read_units_percent >=
get_table_option(key_name, 'reads_upper_threshold')):
if get_table_option(key_name, 'increase_reads_unit') == 'percent':
updated_provisioning = calculators.increase_reads_in_percent(
table_name,
updated_read_units,
get_table_option(key_name, 'increase_reads_with'),
key_name)
else:
updated_provisioning = calculators.increase_reads_in_units(
table_name,
updated_read_units,
get_table_option(key_name, 'increase_reads_with'),
key_name)
update_needed = True
updated_read_units = updated_provisioning
elif (consumed_read_units_percent <=
get_table_option(key_name, 'reads_lower_threshold')):
if get_table_option(key_name, 'decrease_reads_unit') == 'percent':
updated_provisioning = calculators.decrease_reads_in_percent(
table_name,
updated_read_units,
get_table_option(key_name, 'decrease_reads_with'),
key_name)
else:
updated_provisioning = calculators.decrease_reads_in_units(
table_name,
updated_read_units,
get_table_option(key_name, 'decrease_reads_with'),
key_name)
update_needed = True
updated_read_units = updated_provisioning
return update_needed, int(updated_read_units)
