def publish_gsi_notification(
table_key, gsi_key, message, message_types, subject=None):
""" Publish a notification for a specific GSI
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_key: str
:param gsi_key: Table configuration option key name
:type message: str
:param message: Message to send via SNS
:type message_types: list
:param message_types: List with types: scale-up, scale-down, error-message
:type subject: str
:param subject: Subject to use for e-mail notifications
:returns: None
"""
topic = get_gsi_option(table_key, gsi_key, 'sns_topic_arn')
if not topic:
return
for message_type in message_types:
if (message_type in
get_gsi_option(table_key, gsi_key, 'sns_message_types')):
__publish(topic, message, subject)
return
def publish_gsi_notification(
table_key, gsi_key, message, message_types, subject=None):
""" Publish a notification for a specific GSI
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_key: str
:param gsi_key: Table configuration option key name
:type message: str
:param message: Message to send via SNS
:type message_types: list
:param message_types:
List with types:
- scale-up
- scale-down
- high-throughput-alarm
- low-throughput-alarm
:type subject: str
:param subject: Subject to use for e-mail notifications
:returns: None
"""
topic = get_gsi_option(table_key, gsi_key, 'sns_topic_arn')
if not topic:
return
for message_type in message_types:
if (message_type in
get_gsi_option(table_key, gsi_key, 'sns_message_types')):
__publish(topic, message, subject)
return
def increase_reads_in_units(
current_provisioning, units, table_name, table_key, gsi_name, gsi_key):
""" Increase the current_provisioning with units units
:type current_provisioning: int
:param current_provisioning: The current provisioning
:type units: int
:param units: How many units should we increase with
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Name of the key
:returns: int -- New provisioning value
"""
updated_provisioning = 0
if int(units) > int(current_provisioning):
updated_provisioning = 2 * int(current_provisioning)
else:
updated_provisioning = int(current_provisioning) + int(units)
if get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'):
max_provisioned_reads = int(get_gsi_option(
table_key, gsi_key, 'max_provisioned_reads'))
else:
max_provisioned_reads = 0
if (max_provisioned_reads > 0 and
updated_provisioning > max_provisioned_reads):
logger.info(
'{0} - GSI: {1} - '
'Reached provisioned reads max limit: {2:d}'.format(
table_name,
gsi_name,
max_provisioned_reads))
return max_provisioned_reads
logger.debug(
'{0} - GSI: {1} - '
'Read provisioning will be increased to {2:d} units'.format(
table_name,
gsi_name,
updated_provisioning))
return updated_provisioning
def increase_writes_in_percent(
current_provisioning, percent, table_name, table_key,
gsi_name, gsi_key):
""" Increase the current_provisioning with percent %
:type current_provisioning: int
:param current_provisioning: The current provisioning
:type percent: int
:param percent: How many percent should we increase with
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Name of the key
:returns: int -- New provisioning value
"""
increase = int(math.ceil(float(current_provisioning)*(float(percent)/100)))
updated_provisioning = current_provisioning + increase
if get_gsi_option(table_key, gsi_key, 'max_provisioned_writes'):
max_provisioned_writes = int(get_gsi_option(
table_key, gsi_key, 'max_provisioned_writes'))
else:
max_provisioned_writes = 0
if (max_provisioned_writes > 0 and
updated_provisioning > max_provisioned_writes):
logger.info(
'{0} - GSI: {1} - '
'Reached provisioned writes max limit: {2:d}'.format(
table_name,
gsi_name,
max_provisioned_writes))
return max_provisioned_writes
logger.debug(
'{0} - GSI: {1}'
'Write provisioning will be increased to {2:d} units'.format(
table_name,
gsi_name,
updated_provisioning))
return updated_provisioning
def increase_reads_in_percent(
current_provisioning, percent, table_name, table_key,
gsi_name, gsi_key):
""" Increase the current_provisioning with percent %
:type current_provisioning: int
:param current_provisioning: The current provisioning
:type percent: int
:param percent: How many percent should we increase with
:returns: int -- New provisioning value
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Name of the key
"""
increase = int(float(current_provisioning)*(float(percent)/100))
updated_provisioning = current_provisioning + increase
if get_gsi_option(table_key, gsi_key, 'max_provisioned_reads') > 0:
if (updated_provisioning > get_gsi_option(
table_key, gsi_key, 'max_provisioned_reads')):
logger.info(
'{0} - GSI: {1} - '
'Reached provisioned reads max limit: {2:d}'.format(
table_name,
gsi_name,
int(get_gsi_option(
table_key, gsi_key, 'max_provisioned_reads'))))
return get_gsi_option(
table_key, gsi_key, 'max_provisioned_reads')
logger.debug(
'{0} - GSI: {1} - '
'Read provisioning will be increased to {2:d} units'.format(
table_name,
gsi_name,
updated_provisioning))
return updated_provisioning
def __update_throughput(table_name, table_key, gsi_name, gsi_key, read_units,
write_units):
""" Update throughput on the GSI
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:type read_units: int
:param read_units: New read unit provisioning
:type write_units: int
:param write_units: New write unit provisioning
"""
try:
current_ru = dynamodb.get_provisioned_gsi_read_units(
table_name, gsi_name)
current_wu = dynamodb.get_provisioned_gsi_write_units(
table_name, gsi_name)
except JSONResponseError:
raise
# Check table status
try:
gsi_status = dynamodb.get_gsi_status(table_name, gsi_name)
except JSONResponseError:
raise
logger.debug('{0} - GSI: {1} - GSI status is {2}'.format(
table_name, gsi_name, gsi_status))
if gsi_status != 'ACTIVE':
logger.warning(
'{0} - GSI: {1} - Not performing throughput changes when GSI '
'status is {2}'.format(table_name, gsi_name, gsi_status))
return
# If this setting is True, we will only scale down when
# BOTH reads AND writes are low
if get_gsi_option(table_key, gsi_key, 'always_decrease_rw_together'):
read_units, write_units = __calculate_always_decrease_rw_values(
table_name, gsi_name, read_units, current_ru, write_units,
current_wu)
if read_units == current_ru and write_units == current_wu:
logger.info('{0} - GSI: {1} - No changes to perform'.format(
table_name, gsi_name))
return
dynamodb.update_gsi_provisioning(table_name, table_key, gsi_name, gsi_key,
int(read_units), int(write_units))
def get_min_provisioned_reads(
current_provisioning, table_name, table_key, gsi_name, gsi_key):
""" Returns the minimum provisioned reads
If the min_provisioned_reads value is less than current_provisioning * 2,
then we return current_provisioning * 2, as DynamoDB cannot be scaled up
with more than 100%.
:type current_provisioning: int
:param current_provisioning: The current provisioning
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Name of the key
:returns: int -- Minimum provisioned reads
"""
min_provisioned_reads = 1
if get_gsi_option(table_key, gsi_key, 'min_provisioned_reads'):
min_provisioned_reads = int(get_gsi_option(
table_key, gsi_key, 'min_provisioned_reads'))
if min_provisioned_reads > int(current_provisioning * 2):
min_provisioned_reads = int(current_provisioning * 2)
logger.debug(
'{0} - GSI: {1} - '
'Cannot reach min_provisioned_reads as max scale up '
'is 100% of current provisioning'.format(
table_name, gsi_name))
logger.debug(
'{0} - GSI: {1} - '
'Setting min provisioned reads to {2}'.format(
table_name, gsi_name, min_provisioned_reads))
return min_provisioned_reads
def publish_gsi_notification(table_key, gsi_key, message, message_types, subject=None):
""" Publish a notification for a specific GSI
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_key: str
:param gsi_key: Table configuration option key name
:type message: str
:param message: Message to send via SNS
:type message_types: list
:param message_types: List with types: scale-up, scale-down, error-message
:type subject: str
:param subject: Subject to use for e-mail notifications
:returns: None
"""
topic = get_gsi_option(table_key, gsi_key, "sns_topic_arn")
if not topic:
return
for message_type in message_types:
if message_type in get_gsi_option(table_key, gsi_key, "sns_message_types"):
__publish(topic, message, subject)
return
def __update_throughput(table_name, table_key, gsi_name, gsi_key, read_units, write_units):
""" Update throughput on the GSI
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:type read_units: int
:param read_units: New read unit provisioning
:type write_units: int
:param write_units: New write unit provisioning
"""
try:
current_ru = dynamodb.get_provisioned_gsi_read_units(table_name, gsi_name)
current_wu = dynamodb.get_provisioned_gsi_write_units(table_name, gsi_name)
except JSONResponseError:
raise
# Check table status
try:
gsi_status = dynamodb.get_gsi_status(table_name, gsi_name)
except JSONResponseError:
raise
logger.debug("{0} - GSI: {1} - GSI status is {2}".format(table_name, gsi_name, gsi_status))
if gsi_status != "ACTIVE":
logger.warning(
"{0} - GSI: {1} - Not performing throughput changes when GSI "
"status is {2}".format(table_name, gsi_name, gsi_status)
)
return
# If this setting is True, we will only scale down when
# BOTH reads AND writes are low
if get_gsi_option(table_key, gsi_key, "always_decrease_rw_together"):
read_units, write_units = __calculate_always_decrease_rw_values(
table_name, gsi_name, read_units, current_ru, write_units, current_wu
)
if read_units == current_ru and write_units == current_wu:
logger.info("{0} - GSI: {1} - No changes to perform".format(table_name, gsi_name))
return
dynamodb.update_gsi_provisioning(table_name, table_key, gsi_name, gsi_key, int(read_units), int(write_units))
def __ensure_provisioning_reads(table_name, table_key, gsi_name, gsi_key):
""" Ensure that provisioning is correct
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:returns: (bool, int) -- update_needed, updated_read_units
"""
update_needed = False
updated_read_units = gsi_stats.get_provisioned_read_units(
table_name, gsi_name)
consumed_read_units_percent = gsi_stats.get_consumed_read_units_percent(
table_name, gsi_name)
if (consumed_read_units_percent == 0 and not
get_gsi_option(
table_key,
gsi_key,
'allow_scaling_down_reads_on_0_percent')):
logger.info(
'{0} - GSI: {1} - '
'Scaling down reads is not done when usage is at 0%'.format(
table_name, gsi_name))
elif (consumed_read_units_percent >=
get_gsi_option(table_key, gsi_key, 'reads_upper_threshold')):
if (get_gsi_option(table_key, gsi_key, 'increase_reads_unit') ==
'percent'):
updated_provisioning = calculators.increase_reads_in_percent(
updated_read_units,
get_gsi_option(table_key, gsi_key, 'increase_reads_with'),
table_name,
table_key,
gsi_name,
gsi_key,)
else:
updated_provisioning = calculators.increase_reads_in_units(
updated_read_units,
get_gsi_option(table_key, gsi_key, 'increase_reads_with'),
table_name,
table_key,
gsi_name,
gsi_key)
if updated_read_units != updated_provisioning:
update_needed = True
updated_read_units = updated_provisioning
elif (consumed_read_units_percent <=
get_gsi_option(table_key, gsi_key, 'reads_lower_threshold')):
if (get_gsi_option(table_key, gsi_key, 'decrease_reads_unit') ==
'percent'):
updated_provisioning = calculators.decrease_reads_in_percent(
updated_read_units,
get_gsi_option(table_key, gsi_key, 'decrease_reads_with'),
table_name,
table_key,
gsi_name,
gsi_key)
else:
updated_provisioning = calculators.decrease_reads_in_units(
updated_read_units,
get_gsi_option(table_key, gsi_key, 'decrease_reads_with'),
table_name,
table_key,
gsi_name,
gsi_key)
if updated_read_units != updated_provisioning:
update_needed = True
updated_read_units = updated_provisioning
if get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'):
if (int(updated_read_units) > int(
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'))):
update_needed = True
updated_read_units = int(
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'))
logger.info(
'Will not increase writes over gsi-max-provisioned-reads '
'limit ({0} writes)'.format(updated_read_units))
return update_needed, int(updated_read_units)
def __update_throughput(
table_name, table_key, gsi_name, gsi_key, read_units, write_units):
""" Update throughput on the GSI
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:type read_units: int
:param read_units: New read unit provisioning
:type write_units: int
:param write_units: New write unit provisioning
"""
current_ru = gsi_stats.get_provisioned_read_units(
table_name, gsi_name)
current_wu = gsi_stats.get_provisioned_write_units(
table_name, gsi_name)
# Check that we are in the right time frame
if get_gsi_option(table_key, gsi_key, 'maintenance_windows'):
if (not __is_maintenance_window(table_name, gsi_name, get_gsi_option(
table_key, gsi_key, 'maintenance_windows'))):
logger.warning(
'{0} - GSI: {1} - '
'Current time is outside maintenance window'.format(
table_name,
gsi_name))
return
else:
logger.info(
'{0} - GSI: {1} - '
'Current time is within maintenance window'.format(
table_name,
gsi_name))
# Check table status
gsi_status = dynamodb.get_gsi_status(table_name, gsi_name)
logger.debug('{0} - GSI: {1} - GSI status is {2}'.format(
table_name, gsi_name, gsi_status))
if gsi_status != 'ACTIVE':
logger.warning(
'{0} - GSI: {1} - Not performing throughput changes when GSI '
'status is {2}'.format(table_name, gsi_name, gsi_status))
return
# If this setting is True, we will only scale down when
# BOTH reads AND writes are low
if get_gsi_option(table_key, gsi_key, 'always_decrease_rw_together'):
if read_units < current_ru and write_units < current_wu:
logger.debug(
'{0} - GSI: {1} - '
'Both reads and writes will be decreased'.format(
table_name,
gsi_name))
elif read_units < current_ru:
logger.info(
'{0} - GSI: {1} - '
'Will not decrease reads nor writes, waiting for '
'both to become low before decrease'.format(
table_name, gsi_name))
return
elif write_units < current_wu:
logger.info(
'{0} - GSI: {1} - '
'Will not decrease reads nor writes, waiting for '
'both to become low before decrease'.format(
table_name, gsi_name))
return
if not get_global_option('dry_run'):
dynamodb.update_gsi_provisioning(
table_name,
gsi_name,
int(read_units),
int(write_units))
logger.info(
'{0} - GSI: {1} - '
'Provisioning updated to {2} reads and {3} writes'.format(
table_name,
gsi_name,
read_units,
write_units))
def __update_throughput(
table_name, table_key, gsi_name, gsi_key, read_units, write_units):
""" Update throughput on the GSI
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:type read_units: int
:param read_units: New read unit provisioning
:type write_units: int
:param write_units: New write unit provisioning
"""
try:
current_ru = dynamodb.get_provisioned_gsi_read_units(
table_name, gsi_name)
current_wu = dynamodb.get_provisioned_gsi_write_units(
table_name, gsi_name)
except JSONResponseError:
raise
# Check that we are in the right time frame
if get_gsi_option(table_key, gsi_key, 'maintenance_windows'):
if (not __is_maintenance_window(table_name, gsi_name, get_gsi_option(
table_key, gsi_key, 'maintenance_windows'))):
logger.warning(
'{0} - GSI: {1} - '
'Current time is outside maintenance window'.format(
table_name,
gsi_name))
return
else:
logger.info(
'{0} - GSI: {1} - '
'Current time is within maintenance window'.format(
table_name,
gsi_name))
# Check table status
try:
gsi_status = dynamodb.get_gsi_status(table_name, gsi_name)
except JSONResponseError:
raise
logger.debug('{0} - GSI: {1} - GSI status is {2}'.format(
table_name, gsi_name, gsi_status))
if gsi_status != 'ACTIVE':
logger.warning(
'{0} - GSI: {1} - Not performing throughput changes when GSI '
'status is {2}'.format(table_name, gsi_name, gsi_status))
return
# If this setting is True, we will only scale down when
# BOTH reads AND writes are low
if get_gsi_option(table_key, gsi_key, 'always_decrease_rw_together'):
read_units, write_units = __calculate_always_decrease_rw_values(
table_name,
gsi_name,
read_units,
current_ru,
write_units,
current_wu)
if read_units == current_ru and write_units == current_wu:
logger.info('{0} - GSI: {1} - No changes to perform'.format(
table_name, gsi_name))
return
if not get_global_option('dry_run'):
dynamodb.update_gsi_provisioning(
table_name,
table_key,
gsi_name,
gsi_key,
int(read_units),
int(write_units))
logger.info(
'{0} - GSI: {1} - '
'Provisioning updated to {2} reads and {3} writes'.format(
table_name,
gsi_name,
read_units,
write_units))
def __ensure_provisioning_writes(table_name, table_key, gsi_name, gsi_key):
""" Ensure that provisioning of writes is correct
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:returns: (bool, int) -- update_needed, updated_write_units
"""
if not get_gsi_option(table_key, gsi_key, 'enable_writes_autoscaling'):
logger.info(
'{0} - GSI: {1} - '
'Autoscaling of writes has been disabled'.format(
table_name, gsi_name))
return False, dynamodb.get_provisioned_gsi_write_units(
table_name, gsi_name)
update_needed = False
try:
updated_write_units = dynamodb.get_provisioned_gsi_write_units(
table_name, gsi_name)
consumed_write_units_percent = \
gsi_stats.get_consumed_write_units_percent(table_name, gsi_name)
throttled_write_count = \
gsi_stats.get_throttled_write_event_count(table_name, gsi_name)
writes_upper_threshold = \
get_gsi_option(table_key, gsi_key, 'writes_upper_threshold')
writes_lower_threshold = \
get_gsi_option(table_key, gsi_key, 'writes_lower_threshold')
throttled_writes_upper_threshold = \
get_gsi_option(
table_key, gsi_key, 'throttled_writes_upper_threshold')
increase_writes_unit = \
get_gsi_option(table_key, gsi_key, 'increase_writes_unit')
increase_writes_with = \
get_gsi_option(table_key, gsi_key, 'increase_writes_with')
decrease_writes_unit = \
get_gsi_option(table_key, gsi_key, 'decrease_writes_unit')
decrease_writes_with = \
get_gsi_option(table_key, gsi_key, 'decrease_writes_with')
max_provisioned_writes = \
get_gsi_option(table_key, gsi_key, 'max_provisioned_writes')
except JSONResponseError:
raise
except BotoServerError:
raise
# Check if we should update write provisioning
if (consumed_write_units_percent == 0 and not get_gsi_option(
table_key, gsi_key, 'allow_scaling_down_writes_on_0_percent')):
logger.info(
'{0} - GSI: {1} - '
'Scaling down writes is not done when usage is at 0%'.format(
table_name, gsi_name))
elif consumed_write_units_percent >= writes_upper_threshold:
if increase_writes_unit == 'percent':
updated_provisioning = calculators.increase_writes_in_percent(
updated_write_units,
increase_writes_with,
table_name,
table_key,
gsi_name,
gsi_key)
else:
updated_provisioning = calculators.increase_writes_in_units(
updated_write_units,
increase_writes_with,
table_name,
table_key,
gsi_name,
gsi_key)
if updated_write_units != updated_provisioning:
update_needed = True
updated_write_units = updated_provisioning
elif throttled_write_count > throttled_writes_upper_threshold:
if throttled_writes_upper_threshold > 0:
if increase_writes_unit == 'percent':
updated_provisioning = calculators.increase_writes_in_percent(
updated_write_units,
increase_writes_with,
table_name,
table_key,
gsi_name,
gsi_key)
else:
updated_provisioning = calculators.increase_writes_in_units(
updated_write_units,
increase_writes_with,
table_name,
table_key,
gsi_name,
gsi_key)
if updated_write_units != updated_provisioning:
update_needed = True
updated_write_units = updated_provisioning
elif consumed_write_units_percent <= writes_lower_threshold:
if decrease_writes_unit == 'percent':
updated_provisioning = calculators.decrease_writes_in_percent(
updated_write_units,
decrease_writes_with,
table_name,
table_key,
gsi_name,
gsi_key)
else:
updated_provisioning = calculators.decrease_writes_in_units(
updated_write_units,
decrease_writes_with,
table_name,
table_key,
gsi_name,
gsi_key)
if updated_write_units != updated_provisioning:
update_needed = True
updated_write_units = updated_provisioning
if max_provisioned_writes:
if int(updated_write_units) > int(max_provisioned_writes):
update_needed = True
updated_write_units = int(max_provisioned_writes)
logger.info(
'{0} - GSI: {1} - '
'Will not increase writes over gsi-max-provisioned-writes '
'limit ({2} writes)'.format(
table_name,
gsi_name,
updated_write_units))
return update_needed, int(updated_write_units)
def __ensure_provisioning_writes(
table_name, table_key, gsi_name, gsi_key, num_consec_write_checks):
""" Ensure that provisioning of writes is correct
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:type num_consec_write_checks: int
:param num_consec_write_checks: How many consecutive checks have we had
:returns: (bool, int, int)
update_needed, updated_write_units, num_consec_write_checks
"""
if not get_gsi_option(table_key, gsi_key, 'enable_writes_autoscaling'):
logger.info(
'{0} - GSI: {1} - '
'Autoscaling of writes has been disabled'.format(
table_name, gsi_name))
return False, dynamodb.get_provisioned_gsi_write_units(
table_name, gsi_name), 0
update_needed = False
try:
lookback_window_start = get_gsi_option(
table_key, gsi_key, 'lookback_window_start')
current_write_units = dynamodb.get_provisioned_gsi_write_units(
table_name, gsi_name)
consumed_write_units_percent = \
gsi_stats.get_consumed_write_units_percent(
table_name, gsi_name, lookback_window_start)
throttled_write_count = \
gsi_stats.get_throttled_write_event_count(
table_name, gsi_name, lookback_window_start)
throttled_by_provisioned_write_percent = \
gsi_stats.get_throttled_by_provisioned_write_event_percent(
table_name, gsi_name, lookback_window_start)
throttled_by_consumed_write_percent = \
gsi_stats.get_throttled_by_consumed_write_percent(
table_name, gsi_name, lookback_window_start)
writes_upper_threshold = \
get_gsi_option(table_key, gsi_key, 'writes_upper_threshold')
writes_lower_threshold = \
get_gsi_option(table_key, gsi_key, 'writes_lower_threshold')
throttled_writes_upper_threshold = \
get_gsi_option(
table_key, gsi_key, 'throttled_writes_upper_threshold')
increase_writes_unit = \
get_gsi_option(table_key, gsi_key, 'increase_writes_unit')
increase_writes_with = \
get_gsi_option(table_key, gsi_key, 'increase_writes_with')
decrease_writes_unit = \
get_gsi_option(table_key, gsi_key, 'decrease_writes_unit')
decrease_writes_with = \
get_gsi_option(table_key, gsi_key, 'decrease_writes_with')
min_provisioned_writes = \
get_gsi_option(table_key, gsi_key, 'min_provisioned_writes')
max_provisioned_writes = \
get_gsi_option(table_key, gsi_key, 'max_provisioned_writes')
num_write_checks_before_scale_down = \
get_gsi_option(
table_key, gsi_key, 'num_write_checks_before_scale_down')
num_write_checks_reset_percent = \
get_gsi_option(table_key, gsi_key, 'num_write_checks_reset_percent')
increase_throttled_by_provisioned_writes_unit = \
get_gsi_option(
table_key,
gsi_key,
'increase_throttled_by_provisioned_writes_unit')
increase_throttled_by_provisioned_writes_scale = \
get_gsi_option(
table_key,
gsi_key,
'increase_throttled_by_provisioned_writes_scale')
increase_throttled_by_consumed_writes_unit = \
get_gsi_option(
table_key,
gsi_key,
'increase_throttled_by_consumed_writes_unit')
increase_throttled_by_consumed_writes_scale = \
get_gsi_option(
table_key,
gsi_key,
'increase_throttled_by_consumed_writes_scale')
increase_consumed_writes_unit = \
get_gsi_option(table_key, gsi_key, 'increase_consumed_writes_unit')
increase_consumed_writes_with = \
get_gsi_option(table_key, gsi_key, 'increase_consumed_writes_with')
increase_consumed_writes_scale = \
get_gsi_option(table_key, gsi_key, 'increase_consumed_writes_scale')
except JSONResponseError:
raise
except BotoServerError:
raise
# Set the updated units to the current write unit value
updated_write_units = current_write_units
# Reset write consecutive count if num_write_checks_reset_percent is reached
if num_write_checks_reset_percent:
if consumed_write_units_percent >= num_write_checks_reset_percent:
logger.info(
'{0} - GSI: {1} - Resetting the number of consecutive '
'write checks. Reason: Consumed percent {2} is '
'greater than reset percent: {3}'.format(
table_name,
gsi_name,
consumed_write_units_percent,
num_write_checks_reset_percent))
num_consec_write_checks = 0
# Check if we should update write provisioning
if (consumed_write_units_percent == 0 and not get_gsi_option(
table_key, gsi_key, 'allow_scaling_down_writes_on_0_percent')):
logger.info(
'{0} - GSI: {1} - '
'Scaling down writes is not done when usage is at 0%'.format(
table_name, gsi_name))
# Exit if up scaling has been disabled
if not get_gsi_option(table_key, gsi_key, 'enable_writes_up_scaling'):
logger.debug(
'{0} - GSI: {1} - Up scaling event detected. No action taken as '
'scaling up writes has been disabled in the configuration'.format(
table_name, gsi_name))
else:
# If local/granular values not specified use global values
increase_consumed_writes_unit = \
increase_consumed_writes_unit or increase_writes_unit
increase_throttled_by_provisioned_writes_unit = (
increase_throttled_by_provisioned_writes_unit
or increase_writes_unit)
increase_throttled_by_consumed_writes_unit = \
increase_throttled_by_consumed_writes_unit or increase_writes_unit
increase_consumed_writes_with = \
increase_consumed_writes_with or increase_writes_with
# Initialise variables to store calculated provisioning
throttled_by_provisioned_calculated_provisioning = scale_reader(
increase_throttled_by_provisioned_writes_scale,
throttled_by_provisioned_write_percent)
throttled_by_consumed_calculated_provisioning = scale_reader(
increase_throttled_by_consumed_writes_scale,
throttled_by_consumed_write_percent)
consumed_calculated_provisioning = scale_reader(
increase_consumed_writes_scale,
consumed_write_units_percent)
throttled_count_calculated_provisioning = 0
calculated_provisioning = 0
# Increase needed due to high throttled to provisioned ratio
if throttled_by_provisioned_calculated_provisioning:
if increase_throttled_by_provisioned_writes_unit == 'percent':
throttled_by_provisioned_calculated_provisioning = \
calculators.increase_writes_in_percent(
current_write_units,
throttled_by_provisioned_calculated_provisioning,
get_gsi_option(
table_key,
gsi_key,
'max_provisioned_writes'),
consumed_write_units_percent,
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
throttled_by_provisioned_calculated_provisioning = \
calculators.increase_writes_in_units(
current_write_units,
throttled_by_provisioned_calculated_provisioning,
get_gsi_option(
table_key,
gsi_key,
'max_provisioned_writes'),
consumed_write_units_percent,
'{0} - GSI: {1}'.format(table_name, gsi_name))
# Increase needed due to high throttled to consumed ratio
if throttled_by_consumed_calculated_provisioning:
if increase_throttled_by_consumed_writes_unit == 'percent':
throttled_by_consumed_calculated_provisioning = \
calculators.increase_writes_in_percent(
current_write_units,
throttled_by_consumed_calculated_provisioning,
get_gsi_option(
table_key,
gsi_key,
'max_provisioned_writes'),
consumed_write_units_percent,
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
throttled_by_consumed_calculated_provisioning = \
calculators.increase_writes_in_units(
current_write_units,
throttled_by_consumed_calculated_provisioning,
get_gsi_option(
table_key,
gsi_key,
'max_provisioned_writes'),
consumed_write_units_percent,
'{0} - GSI: {1}'.format(table_name, gsi_name))
# Increase needed due to high CU consumption
if consumed_calculated_provisioning:
if increase_consumed_writes_unit == 'percent':
consumed_calculated_provisioning = \
calculators.increase_writes_in_percent(
current_write_units,
consumed_calculated_provisioning,
get_gsi_option(
table_key,
gsi_key,
'max_provisioned_writes'),
consumed_write_units_percent,
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
consumed_calculated_provisioning = \
calculators.increase_writes_in_units(
current_write_units,
consumed_calculated_provisioning,
get_gsi_option(
table_key,
gsi_key,
'max_provisioned_writes'),
consumed_write_units_percent,
'{0} - GSI: {1}'.format(table_name, gsi_name))
elif (writes_upper_threshold
and consumed_write_units_percent > writes_upper_threshold
and not increase_consumed_writes_scale):
if increase_consumed_writes_unit == 'percent':
consumed_calculated_provisioning = \
calculators.increase_writes_in_percent(
current_write_units,
increase_consumed_writes_with,
get_gsi_option(
table_key,
gsi_key,
'max_provisioned_writes'),
consumed_write_units_percent,
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
consumed_calculated_provisioning = \
calculators.increase_writes_in_units(
current_write_units,
increase_consumed_writes_with,
get_gsi_option(
table_key, gsi_key, 'max_provisioned_writes'),
consumed_write_units_percent,
'{0} - GSI: {1}'.format(table_name, gsi_name))
# Increase needed due to high throttling
if (throttled_writes_upper_threshold
and throttled_write_count > throttled_writes_upper_threshold):
if increase_writes_unit == 'percent':
throttled_count_calculated_provisioning = \
calculators.increase_writes_in_percent(
updated_write_units,
increase_writes_with,
get_gsi_option(
table_key, gsi_key, 'max_provisioned_writes'),
consumed_write_units_percent,
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
throttled_count_calculated_provisioning = \
calculators.increase_writes_in_units(
updated_write_units,
increase_writes_with,
get_gsi_option(
table_key, gsi_key, 'max_provisioned_writes'),
consumed_write_units_percent,
'{0} - GSI: {1}'.format(table_name, gsi_name))
# Determine which metric requires the most scaling
if (throttled_by_provisioned_calculated_provisioning
> calculated_provisioning):
calculated_provisioning = \
throttled_by_provisioned_calculated_provisioning
scale_reason = (
"due to throttled events by provisioned "
"units threshold being exceeded")
if (throttled_by_consumed_calculated_provisioning
> calculated_provisioning):
calculated_provisioning = \
throttled_by_consumed_calculated_provisioning
scale_reason = (
"due to throttled events by consumed "
"units threshold being exceeded")
if consumed_calculated_provisioning > calculated_provisioning:
calculated_provisioning = consumed_calculated_provisioning
scale_reason = "due to consumed threshold being exceeded"
if throttled_count_calculated_provisioning > calculated_provisioning:
calculated_provisioning = throttled_count_calculated_provisioning
scale_reason = "due to throttled events threshold being exceeded"
if calculated_provisioning > current_write_units:
logger.info(
'{0} - GSI: {1} - Resetting the number of consecutive '
'write checks. Reason: scale up {2}'.format(
table_name, gsi_name, scale_reason))
num_consec_write_checks = 0
update_needed = True
updated_write_units = calculated_provisioning
# Decrease needed due to low CU consumption
if (consumed_write_units_percent
<= writes_lower_threshold and not update_needed):
# Exit if down scaling has been disabled
if not get_gsi_option(table_key, gsi_key, 'enable_writes_down_scaling'):
logger.debug(
'{0} - GSI: {1} - Down scaling event detected. '
'No action taken as scaling '
'down writes has been disabled in the configuration'.format(
table_name, gsi_name))
else:
if decrease_writes_unit == 'percent':
calculated_provisioning = \
calculators.decrease_writes_in_percent(
current_write_units,
decrease_writes_with,
get_gsi_option(
table_key, gsi_key, 'min_provisioned_writes'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calculated_provisioning = calculators.decrease_writes_in_units(
current_write_units,
decrease_writes_with,
get_gsi_option(
table_key, gsi_key, 'min_provisioned_writes'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_write_units != calculated_provisioning:
num_consec_write_checks = num_consec_write_checks + 1
if (num_consec_write_checks >=
num_write_checks_before_scale_down):
update_needed = True
updated_write_units = calculated_provisioning
# Never go over the configured max provisioning
if max_provisioned_writes:
if int(updated_write_units) > int(max_provisioned_writes):
update_needed = True
updated_write_units = int(max_provisioned_writes)
logger.info(
'{0} - GSI: {1} - '
'Will not increase writes over gsi-max-provisioned-writes '
'limit ({2} writes)'.format(
table_name,
gsi_name,
updated_write_units))
# Ensure that we have met the min-provisioning
if min_provisioned_writes:
if int(min_provisioned_writes) > int(updated_write_units):
update_needed = True
updated_write_units = int(min_provisioned_writes)
logger.info(
'{0} - GSI: {1} - Increasing writes to'
'meet gsi-min-provisioned-writes '
'limit ({2} writes)'.format(
table_name,
gsi_name,
updated_write_units))
logger.info('{0} - GSI: {1} - Consecutive write checks {2}/{3}'.format(
table_name,
gsi_name,
num_consec_write_checks,
num_write_checks_before_scale_down))
return update_needed, updated_write_units, num_consec_write_checks
def __ensure_provisioning_alarm(table_name, table_key, gsi_name, gsi_key):
""" Ensure that provisioning alarm threshold is not exceeded
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
"""
lookback_window_start = get_gsi_option(table_key, gsi_key,
'lookback_window_start')
consumed_read_units_percent = gsi_stats.get_consumed_read_units_percent(
table_name, gsi_name, lookback_window_start)
consumed_write_units_percent = gsi_stats.get_consumed_write_units_percent(
table_name, gsi_name, lookback_window_start)
reads_upper_alarm_threshold = \
get_gsi_option(table_key, gsi_key, 'reads-upper-alarm-threshold')
reads_lower_alarm_threshold = \
get_gsi_option(table_key, gsi_key, 'reads-lower-alarm-threshold')
writes_upper_alarm_threshold = \
get_gsi_option(table_key, gsi_key, 'writes-upper-alarm-threshold')
writes_lower_alarm_threshold = \
get_gsi_option(table_key, gsi_key, 'writes-lower-alarm-threshold')
# Check upper alarm thresholds
upper_alert_triggered = False
upper_alert_message = []
if (reads_upper_alarm_threshold > 0
and consumed_read_units_percent >= reads_upper_alarm_threshold):
upper_alert_triggered = True
upper_alert_message.append(
'{0} - GSI: {1} - Consumed Read Capacity {2:d}% '
'was greater than or equal to the upper alarm '
'threshold {3:d}%\n'.format(table_name, gsi_name,
consumed_read_units_percent,
reads_upper_alarm_threshold))
if (writes_upper_alarm_threshold > 0
and consumed_write_units_percent >= writes_upper_alarm_threshold):
upper_alert_triggered = True
upper_alert_message.append(
'{0} - GSI: {1} - Consumed Write Capacity {2:d}% '
'was greater than or equal to the upper alarm '
'threshold {3:d}%\n'.format(table_name, gsi_name,
consumed_write_units_percent,
writes_upper_alarm_threshold))
# Check lower alarm thresholds
lower_alert_triggered = False
lower_alert_message = []
if (reads_lower_alarm_threshold > 0
and consumed_read_units_percent < reads_lower_alarm_threshold):
lower_alert_triggered = True
lower_alert_message.append(
'{0} - GSI: {1} - Consumed Read Capacity {2:d}% '
'was below the lower alarm threshold {3:d}%\n'.format(
table_name, gsi_name, consumed_read_units_percent,
reads_lower_alarm_threshold))
if (writes_lower_alarm_threshold > 0
and consumed_write_units_percent < writes_lower_alarm_threshold):
lower_alert_triggered = True
lower_alert_message.append(
'{0} - GSI: {1} - Consumed Write Capacity {2:d}% '
'was below the lower alarm threshold {3:d}%\n'.format(
table_name, gsi_name, consumed_write_units_percent,
writes_lower_alarm_threshold))
# Send alert if needed
if upper_alert_triggered:
logger.info(
'{0} - GSI: {1} - Will send high provisioning alert'.format(
table_name, gsi_name))
sns.publish_gsi_notification(
table_key,
gsi_key,
''.join(upper_alert_message), ['high-throughput-alarm'],
subject='ALARM: High Throughput for Table {0} - GSI: {1}'.format(
table_name, gsi_name))
elif lower_alert_triggered:
logger.info('{0} - GSI: {1} - Will send low provisioning alert'.format(
table_name, gsi_name))
sns.publish_gsi_notification(
table_key,
gsi_key,
''.join(lower_alert_message), ['low-throughput-alarm'],
subject='ALARM: Low Throughput for Table {0} - GSI: {1}'.format(
table_name, gsi_name))
else:
logger.debug(
'{0} - GSI: {1} - Throughput alarm thresholds not crossed'.format(
table_name, gsi_name))
def __ensure_provisioning_alarm(table_name, table_key, gsi_name, gsi_key):
""" Ensure that provisioning alarm threshold is not exceeded
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
"""
lookback_window_start = get_gsi_option(
table_key, gsi_key, 'lookback_window_start')
consumed_read_units_percent = gsi_stats.get_consumed_read_units_percent(
table_name, gsi_name, lookback_window_start)
consumed_write_units_percent = gsi_stats.get_consumed_write_units_percent(
table_name, gsi_name, lookback_window_start)
reads_upper_alarm_threshold = \
get_gsi_option(table_key, gsi_key, 'reads-upper-alarm-threshold')
reads_lower_alarm_threshold = \
get_gsi_option(table_key, gsi_key, 'reads-lower-alarm-threshold')
writes_upper_alarm_threshold = \
get_gsi_option(table_key, gsi_key, 'writes-upper-alarm-threshold')
writes_lower_alarm_threshold = \
get_gsi_option(table_key, gsi_key, 'writes-lower-alarm-threshold')
# Check upper alarm thresholds
upper_alert_triggered = False
upper_alert_message = []
if (reads_upper_alarm_threshold > 0 and
consumed_read_units_percent >= reads_upper_alarm_threshold):
upper_alert_triggered = True
upper_alert_message.append(
'{0} - GSI: {1} - Consumed Read Capacity {2:d}% '
'was greater than or equal to the upper alarm '
'threshold {3:d}%\n'.format(
table_name,
gsi_name,
consumed_read_units_percent,
reads_upper_alarm_threshold))
if (writes_upper_alarm_threshold > 0 and
consumed_write_units_percent >= writes_upper_alarm_threshold):
upper_alert_triggered = True
upper_alert_message.append(
'{0} - GSI: {1} - Consumed Write Capacity {2:d}% '
'was greater than or equal to the upper alarm '
'threshold {3:d}%\n'.format(
table_name,
gsi_name,
consumed_write_units_percent,
writes_upper_alarm_threshold))
# Check lower alarm thresholds
lower_alert_triggered = False
lower_alert_message = []
if (reads_lower_alarm_threshold > 0 and
consumed_read_units_percent < reads_lower_alarm_threshold):
lower_alert_triggered = True
lower_alert_message.append(
'{0} - GSI: {1} - Consumed Read Capacity {2:d}% '
'was below the lower alarm threshold {3:d}%\n'.format(
table_name,
gsi_name,
consumed_read_units_percent,
reads_lower_alarm_threshold))
if (writes_lower_alarm_threshold > 0 and
consumed_write_units_percent < writes_lower_alarm_threshold):
lower_alert_triggered = True
lower_alert_message.append(
'{0} - GSI: {1} - Consumed Write Capacity {2:d}% '
'was below the lower alarm threshold {3:d}%\n'.format(
table_name,
gsi_name,
consumed_write_units_percent,
writes_lower_alarm_threshold))
# Send alert if needed
if upper_alert_triggered:
logger.info(
'{0} - GSI: {1} - Will send high provisioning alert'.format(
table_name, gsi_name))
sns.publish_gsi_notification(
table_key,
gsi_key,
''.join(upper_alert_message),
['high-throughput-alarm'],
subject='ALARM: High Throughput for Table {0} - GSI: {1}'.format(
table_name, gsi_name))
elif lower_alert_triggered:
logger.info(
'{0} - GSI: {1} - Will send low provisioning alert'.format(
table_name, gsi_name))
sns.publish_gsi_notification(
table_key,
gsi_key,
''.join(lower_alert_message),
['low-throughput-alarm'],
subject='ALARM: Low Throughput for Table {0} - GSI: {1}'.format(
table_name, gsi_name))
else:
logger.debug(
'{0} - GSI: {1} - Throughput alarm thresholds not crossed'.format(
table_name, gsi_name))
def is_open(table_name=None, table_key=None, gsi_name=None, gsi_key=None):
""" Checks whether the circuit breaker is open
:param table_name: Name of the table being checked
:param table_key: Configuration key for table
:param gsi_name: Name of the GSI being checked
:param gsi_key: Configuration key for the GSI
:returns: bool -- True if the circuit is open
"""
logger.debug('Checking circuit breaker status')
# Parse the URL to make sure it is OK
pattern = re.compile(
r'^(?P<scheme>http(s)?://)'
r'((?P<username>.+):(?P<password>.+)@){0,1}'
r'(?P<url>.*)$'
)
url = timeout = None
if gsi_name:
url = get_gsi_option(table_key, gsi_key, 'circuit_breaker_url')
timeout = get_gsi_option(table_key, gsi_key, 'circuit_breaker_timeout')
elif table_name:
url = get_table_option(table_key, 'circuit_breaker_url')
timeout = get_table_option(table_key, 'circuit_breaker_timeout')
if not url:
url = get_global_option('circuit_breaker_url')
timeout = get_global_option('circuit_breaker_timeout')
match = pattern.match(url)
if not match:
logger.error('Malformatted URL: {0}'.format(url))
sys.exit(1)
use_basic_auth = False
if match.group('username') and match.group('password'):
use_basic_auth = True
# Make the actual URL to call
auth = ()
if use_basic_auth:
url = '{scheme}{url}'.format(
scheme=match.group('scheme'),
url=match.group('url'))
auth = (match.group('username'), match.group('password'))
headers = {}
if table_name:
headers["x-table-name"] = table_name
if gsi_name:
headers["x-gsi-name"] = gsi_name
# Make the actual request
try:
response = requests.get(
url,
auth=auth,
timeout=timeout / 1000.00,
headers=headers)
if int(response.status_code) == 200:
logger.info('Circuit breaker is closed')
return False
else:
logger.warning(
'Circuit breaker returned with status code {0:d}'.format(
response.status_code))
except requests.exceptions.SSLError as error:
logger.warning('Circuit breaker: {0}'.format(error))
except requests.exceptions.Timeout as error:
logger.warning('Circuit breaker: {0}'.format(error))
except requests.exceptions.ConnectionError as error:
logger.warning('Circuit breaker: {0}'.format(error))
except requests.exceptions.HTTPError as error:
logger.warning('Circuit breaker: {0}'.format(error))
except requests.exceptions.TooManyRedirects as error:
logger.warning('Circuit breaker: {0}'.format(error))
except Exception as error:
logger.error('Unhandled exception: {0}'.format(error))
logger.error(
'Please file a bug at '
'https://github.com/sebdah/dynamic-dynamodb/issues')
return True
def update_gsi_provisioning(
table_name, table_key, gsi_name, gsi_key,
reads, writes, retry_with_only_increase=False):
""" Update provisioning on a global secondary index
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: GSI configuration option key name
:type reads: int
:param reads: Number of reads to provision
:type writes: int
:param writes: Number of writes to provision
:type retry_with_only_increase: bool
:param retry_with_only_increase: Set to True to ensure only increases
"""
current_reads = int(get_provisioned_gsi_read_units(table_name, gsi_name))
current_writes = int(get_provisioned_gsi_write_units(table_name, gsi_name))
# Make sure we aren't scaling down if we turned off downscaling
if (not get_gsi_option(table_key, gsi_key, 'enable_reads_down_scaling') or
not get_gsi_option(
table_key, gsi_key, 'enable_writes_down_scaling')):
if (not get_gsi_option(
table_key, gsi_key, 'enable_reads_down_scaling') and
current_reads > reads):
reads = current_reads
if (not get_gsi_option(
table_key, gsi_key, 'enable_writes_down_scaling') and
current_writes > writes):
writes = current_writes
# Return if we do not need to scale at all
if reads == current_reads and writes == current_writes:
logger.info(
'{0} - No need to scale up reads nor writes'.format(
table_name))
return
if retry_with_only_increase:
# Ensure that we are only doing increases
if current_reads > reads:
reads = current_reads
if current_writes > writes:
writes = current_writes
# Return if we do not need to scale at all
if reads == current_reads and writes == current_writes:
logger.info(
'{0} - GSI: {1} - No need to scale up reads nor writes'.format(
table_name, gsi_name))
return
logger.info(
'{0} - GSI: {1} - Retrying to update provisioning, '
'excluding any decreases. '
'Setting new reads to {2} and new writes to {3}'.format(
table_name, gsi_name, reads, writes))
# Check that we are in the right time frame
m_windows = get_gsi_option(table_key, gsi_key, 'maintenance_windows')
if m_windows:
if not __is_gsi_maintenance_window(table_name, gsi_name, m_windows):
logger.warning(
'{0} - GSI: {1} - We are outside a maintenace window. '
'Will only perform up scaling activites'.format(
table_name,
gsi_name))
# Ensure that we are only doing increases
if current_reads > reads:
reads = current_reads
if current_writes > writes:
writes = current_writes
# Return if we do not need to scale up
if reads == current_reads and writes == current_writes:
logger.info(
'{0} - GSI: {1} - '
'No need to scale up reads nor writes'.format(
table_name,
gsi_name))
return
else:
logger.info(
'{0} - GSI: {1} - '
'Current time is within maintenance window'.format(
table_name,
gsi_name))
logger.info(
'{0} - GSI: {1} - '
'Updating provisioning to {2} reads and {3} writes'.format(
table_name, gsi_name, reads, writes))
# Return if dry-run
if get_global_option('dry_run'):
return
try:
DYNAMODB_CONNECTION.update_table(
table_name=table_name,
global_secondary_index_updates=[
{
"Update": {
"IndexName": gsi_name,
"ProvisionedThroughput": {
"ReadCapacityUnits": reads,
"WriteCapacityUnits": writes
}
}
}
])
message = []
if current_reads > reads:
message.append(
'{0} - GSI: {1} - Reads: DOWN from {2} to {3}\n'.format(
table_name, gsi_name, current_reads, reads))
elif current_reads < reads:
message.append(
'{0} - GSI: {1} - Reads: UP from {2} to {3}\n'.format(
table_name, gsi_name, current_reads, reads))
if current_writes > writes:
message.append(
'{0} - GSI: {1} - Writes: DOWN from {2} to {3}\n'.format(
table_name, gsi_name, current_writes, writes))
elif current_writes < writes:
message.append(
'{0} - GSI: {1} - Writes: UP from {2} to {3}\n'.format(
table_name, gsi_name, current_writes, writes))
# See if we should send notifications for scale-down, scale-up or both
sns_message_types = []
if current_reads > reads or current_writes > writes:
sns_message_types.append('scale-down')
if current_reads < reads or current_writes < writes:
sns_message_types.append('scale-up')
sns.publish_gsi_notification(
table_key,
gsi_key,
''.join(message),
sns_message_types,
subject='Updated provisioning for GSI {0}'.format(gsi_name))
except JSONResponseError as error:
exception = error.body['__type'].split('#')[1]
know_exceptions = ['LimitExceededException']
if exception in know_exceptions:
logger.warning('{0} - GSI: {1} - {2}: {3}'.format(
table_name, gsi_name, exception, error.body['message']))
else:
logger.error(
(
'{0} - GSI: {1} - Unhandled exception: {2}: {3}. '
'Please file a bug report at '
'https://github.com/sebdah/dynamic-dynamodb/issues'
).format(
table_name, gsi_name, exception, error.body['message']))
if (not retry_with_only_increase and
exception == 'LimitExceededException'):
logger.info(
'{0} - GSI: {1} - Will retry to update provisioning '
'with only increases'.format(table_name, gsi_name))
update_gsi_provisioning(
table_name,
table_key,
gsi_name,
gsi_key,
reads,
writes,
retry_with_only_increase=True)
def __ensure_provisioning_writes(table_name, table_key, gsi_name, gsi_key, num_consec_write_checks):
""" Ensure that provisioning of writes is correct
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:type num_consec_write_checks: int
:param num_consec_write_checks: How many consecutive checks have we had
:returns: (bool, int, int)
update_needed, updated_write_units, num_consec_write_checks
"""
if not get_gsi_option(table_key, gsi_key, "enable_writes_autoscaling"):
logger.info("{0} - GSI: {1} - " "Autoscaling of writes has been disabled".format(table_name, gsi_name))
return False, dynamodb.get_provisioned_gsi_write_units(table_name, gsi_name), 0
update_needed = False
try:
current_write_units = dynamodb.get_provisioned_gsi_write_units(table_name, gsi_name)
consumed_write_units_percent = gsi_stats.get_consumed_write_units_percent(table_name, gsi_name)
throttled_write_count = gsi_stats.get_throttled_write_event_count(table_name, gsi_name)
writes_upper_threshold = get_gsi_option(table_key, gsi_key, "writes_upper_threshold")
writes_lower_threshold = get_gsi_option(table_key, gsi_key, "writes_lower_threshold")
throttled_writes_upper_threshold = get_gsi_option(table_key, gsi_key, "throttled_writes_upper_threshold")
increase_writes_unit = get_gsi_option(table_key, gsi_key, "increase_writes_unit")
increase_writes_with = get_gsi_option(table_key, gsi_key, "increase_writes_with")
decrease_writes_unit = get_gsi_option(table_key, gsi_key, "decrease_writes_unit")
decrease_writes_with = get_gsi_option(table_key, gsi_key, "decrease_writes_with")
max_provisioned_writes = get_gsi_option(table_key, gsi_key, "max_provisioned_writes")
num_write_checks_before_scale_down = get_gsi_option(table_key, gsi_key, "num_write_checks_before_scale_down")
num_write_checks_reset_percent = get_gsi_option(table_key, gsi_key, "num_write_checks_reset_percent")
except JSONResponseError:
raise
except BotoServerError:
raise
# Set the updated units to the current write unit value
updated_write_units = current_write_units
# Reset write consecutive count if num_write_checks_reset_percent is reached
if num_write_checks_reset_percent:
if consumed_write_units_percent >= num_write_checks_reset_percent:
logger.info(
"{0} - GSI: {1} - Resetting the number of consecutive "
"write checks. Reason: Consumed percent {2} is "
"greater than reset percent: {3}".format(
table_name, gsi_name, consumed_write_units_percent, num_write_checks_reset_percent
)
)
num_consec_write_checks = 0
# Check if we should update write provisioning
if consumed_write_units_percent == 0 and not get_gsi_option(
table_key, gsi_key, "allow_scaling_down_writes_on_0_percent"
):
logger.info(
"{0} - GSI: {1} - " "Scaling down writes is not done when usage is at 0%".format(table_name, gsi_name)
)
elif consumed_write_units_percent >= writes_upper_threshold:
if increase_writes_unit == "percent":
calculated_provisioning = calculators.increase_writes_in_percent(
current_write_units,
increase_writes_with,
get_gsi_option(table_key, gsi_key, "max_provisioned_reads"),
"{0} - GSI: {1}".format(table_name, gsi_name),
)
else:
calculated_provisioning = calculators.increase_writes_in_units(
current_write_units,
increase_writes_with,
get_gsi_option(table_key, gsi_key, "max_provisioned_reads"),
"{0} - GSI: {1}".format(table_name, gsi_name),
)
if current_write_units != calculated_provisioning:
logger.info(
"{0} - GSI: {1} - Resetting the number of consecutive "
"write checks. Reason: scale up event detected".format(table_name, gsi_name)
)
num_consec_write_checks = 0
update_needed = True
updated_write_units = calculated_provisioning
elif throttled_write_count > throttled_writes_upper_threshold:
if throttled_writes_upper_threshold > 0:
if increase_writes_unit == "percent":
calculated_provisioning = calculators.increase_writes_in_percent(
current_write_units,
increase_writes_with,
get_gsi_option(table_key, gsi_key, "max_provisioned_reads"),
"{0} - GSI: {1}".format(table_name, gsi_name),
)
else:
calculated_provisioning = calculators.increase_writes_in_units(
current_write_units,
increase_writes_with,
get_gsi_option(table_key, gsi_key, "max_provisioned_reads"),
"{0} - GSI: {1}".format(table_name, gsi_name),
)
if current_write_units != calculated_provisioning:
logger.info(
"{0} - GSI: {1} - Resetting the number of consecutive "
"write checks. Reason: scale up event detected".format(table_name, gsi_name)
)
num_consec_write_checks = 0
update_needed = True
updated_write_units = calculated_provisioning
elif consumed_write_units_percent <= writes_lower_threshold:
if decrease_writes_unit == "percent":
calculated_provisioning = calculators.decrease_writes_in_percent(
current_write_units,
decrease_writes_with,
get_gsi_option(table_key, gsi_key, "min_provisioned_writes"),
"{0} - GSI: {1}".format(table_name, gsi_name),
)
else:
calculated_provisioning = calculators.decrease_writes_in_units(
current_write_units,
decrease_writes_with,
get_gsi_option(table_key, gsi_key, "min_provisioned_reads"),
"{0} - GSI: {1}".format(table_name, gsi_name),
)
if current_write_units != calculated_provisioning:
num_consec_write_checks = num_consec_write_checks + 1
if num_consec_write_checks >= num_write_checks_before_scale_down:
update_needed = True
updated_write_units = calculated_provisioning
if max_provisioned_writes:
if int(updated_write_units) > int(max_provisioned_writes):
update_needed = True
updated_write_units = int(max_provisioned_writes)
logger.info(
"{0} - GSI: {1} - "
"Will not increase writes over gsi-max-provisioned-writes "
"limit ({2} writes)".format(table_name, gsi_name, updated_write_units)
)
logger.info(
"{0} - GSI: {1} - Consecutive write checks {2}/{3}".format(
table_name, gsi_name, num_consec_write_checks, num_write_checks_before_scale_down
)
)
return update_needed, updated_write_units, num_consec_write_checks
def update_gsi_provisioning(table_name, table_key, gsi_name, gsi_key, reads, writes, retry_with_only_increase=False):
""" Update provisioning on a global secondary index
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: GSI configuration option key name
:type reads: int
:param reads: Number of reads to provision
:type writes: int
:param writes: Number of writes to provision
:type retry_with_only_increase: bool
:param retry_with_only_increase: Set to True to ensure only increases
"""
current_reads = int(get_provisioned_gsi_read_units(table_name, gsi_name))
current_writes = int(get_provisioned_gsi_write_units(table_name, gsi_name))
if retry_with_only_increase:
# Ensure that we are only doing increases
if current_reads > reads:
reads = current_reads
if current_writes > writes:
writes = current_writes
# Return if we do not need to scale at all
if reads == current_reads and writes == current_writes:
logger.info("{0} - GSI: {1} - No need to scale up reads nor writes".format(table_name, gsi_name))
return
logger.info(
"{0} - GSI: {1} - Retrying to update provisioning, excluding any decreases. "
"Setting new reads to {2} and new writes to {3}".format(table_name, gsi_name, reads, writes)
)
# Check that we are in the right time frame
m_windows = get_gsi_option(table_key, gsi_key, "maintenance_windows")
if m_windows:
if not __is_gsi_maintenance_window(table_name, gsi_name, m_windows):
logger.warning(
"{0} - GSI: {1} - We are outside a maintenace window. "
"Will only perform up scaling activites".format(table_name, gsi_name)
)
# Ensure that we are only doing increases
if current_reads > reads:
reads = current_reads
if current_writes > writes:
writes = current_writes
# Return if we do not need to scale up
if reads == current_reads and writes == current_writes:
logger.info("{0} - GSI: {1} - " "No need to scale up reads nor writes".format(table_name, gsi_name))
return
else:
logger.info("{0} - GSI: {1} - " "Current time is within maintenance window".format(table_name, gsi_name))
logger.info(
"{0} - GSI: {1} - "
"Updating provisioning to {2} reads and {3} writes".format(table_name, gsi_name, reads, writes)
)
# Return if dry-run
if get_global_option("dry_run"):
return
try:
DYNAMODB_CONNECTION.update_table(
table_name=table_name,
global_secondary_index_updates=[
{
"Update": {
"IndexName": gsi_name,
"ProvisionedThroughput": {"ReadCapacityUnits": reads, "WriteCapacityUnits": writes},
}
}
],
)
message = ("{0} - GSI: {1} - Provisioning updated to " "{2} reads and {3} writes").format(
table_name, gsi_name, reads, writes
)
# See if we should send notifications for scale-down, scale-up or both
sns_message_types = []
if current_reads > reads or current_writes > current_writes:
sns_message_types.append("scale-down")
if current_reads < reads or current_writes < current_writes:
sns_message_types.append("scale-up")
sns.publish_gsi_notification(
table_key, gsi_key, message, sns_message_types, subject="Updated provisioning for GSI {0}".format(gsi_name)
)
except JSONResponseError as error:
exception = error.body["__type"].split("#")[1]
know_exceptions = ["LimitExceededException"]
if exception in know_exceptions:
logger.warning("{0} - GSI: {1} - {2}: {3}".format(table_name, gsi_name, exception, error.body["message"]))
else:
logger.error(
(
"{0} - GSI: {1} - Unhandled exception: {2}: {3}. "
"Please file a bug report at "
"https://github.com/sebdah/dynamic-dynamodb/issues"
).format(table_name, gsi_name, exception, error.body["message"])
)
if not retry_with_only_increase and exception == "LimitExceededException":
logger.info(
"{0} - GSI: {1} - Will retry to update provisioning " "with only increases".format(table_name, gsi_name)
)
update_gsi_provisioning(
table_name, table_key, gsi_name, gsi_key, reads, writes, retry_with_only_increase=True
)
def is_open(table_name=None, table_key=None, gsi_name=None, gsi_key=None):
""" Checks whether the circuit breaker is open
:param table_name: Name of the table being checked
:param table_key: Configuration key for table
:param gsi_name: Name of the GSI being checked
:param gsi_key: Configuration key for the GSI
:returns: bool -- True if the circuit is open
"""
logger.debug('Checking circuit breaker status')
# Parse the URL to make sure it is OK
pattern = re.compile(r'^(?P<scheme>http(s)?://)'
r'((?P<username>.+):(?P<password>.+)@){0,1}'
r'(?P<url>.*)$')
url = timeout = None
if gsi_name:
url = get_gsi_option(table_key, gsi_key, 'circuit_breaker_url')
timeout = get_gsi_option(table_key, gsi_key, 'circuit_breaker_timeout')
elif table_name:
url = get_table_option(table_key, 'circuit_breaker_url')
timeout = get_table_option(table_key, 'circuit_breaker_timeout')
if not url:
url = get_global_option('circuit_breaker_url')
timeout = get_global_option('circuit_breaker_timeout')
match = pattern.match(url)
if not match:
logger.error('Malformatted URL: {0}'.format(url))
sys.exit(1)
use_basic_auth = False
if match.group('username') and match.group('password'):
use_basic_auth = True
# Make the actual URL to call
auth = ()
if use_basic_auth:
url = '{scheme}{url}'.format(scheme=match.group('scheme'),
url=match.group('url'))
auth = (match.group('username'), match.group('password'))
headers = {}
if table_name:
headers["x-table-name"] = table_name
if gsi_name:
headers["x-gsi-name"] = gsi_name
# Make the actual request
try:
response = requests.get(url,
auth=auth,
timeout=timeout / 1000.00,
headers=headers)
if int(response.status_code) == 200:
logger.info('Circuit breaker is closed')
return False
else:
logger.warning(
'Circuit breaker returned with status code {0:d}'.format(
response.status_code))
except requests.exceptions.SSLError as error:
logger.warning('Circuit breaker: {0}'.format(error))
except requests.exceptions.Timeout as error:
logger.warning('Circuit breaker: {0}'.format(error))
except requests.exceptions.ConnectionError as error:
logger.warning('Circuit breaker: {0}'.format(error))
except requests.exceptions.HTTPError as error:
logger.warning('Circuit breaker: {0}'.format(error))
except requests.exceptions.TooManyRedirects as error:
logger.warning('Circuit breaker: {0}'.format(error))
except Exception as error:
logger.error('Unhandled exception: {0}'.format(error))
logger.error('Please file a bug at '
'https://github.com/sebdah/dynamic-dynamodb/issues')
return True
def update_gsi_provisioning(table_name,
table_key,
gsi_name,
gsi_key,
reads,
writes,
retry_with_only_increase=False):
""" Update provisioning on a global secondary index
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: GSI configuration option key name
:type reads: int
:param reads: Number of reads to provision
:type writes: int
:param writes: Number of writes to provision
:type retry_with_only_increase: bool
:param retry_with_only_increase: Set to True to ensure only increases
"""
current_reads = int(get_provisioned_table_read_units(table_name))
current_writes = int(get_provisioned_table_write_units(table_name))
if retry_with_only_increase:
# Ensure that we are only doing increases
if current_reads > reads:
reads = current_reads
if current_writes > writes:
writes = current_writes
logger.info(
'{0} - Retrying to update provisioning, excluding any decreases. '
'Setting new reads to {1} and new writes to {2}'.format(
table_name, reads, writes))
# Check that we are in the right time frame
m_windows = get_gsi_option(table_key, gsi_key, 'maintenance_windows')
if m_windows:
if not __is_gsi_maintenance_window(table_name, gsi_name, m_windows):
logger.warning(
'{0} - GSI: {1} - We are outside a maintenace window. '
'Will only perform up scaling activites'.format(
table_name, gsi_name))
# Ensure that we are only doing increases
if current_reads > reads:
reads = current_reads
if current_writes > writes:
writes = current_writes
# Return if we do not need to scale up
if reads == current_reads and writes == current_writes:
logger.info('{0} - GSI: {1} - '
'No need to scale up reads nor writes'.format(
table_name, gsi_name))
return
else:
logger.info('{0} - GSI: {1} - '
'Current time is within maintenance window'.format(
table_name, gsi_name))
logger.info('{0} - GSI: {1} - '
'Updating provisioning to {2} reads and {3} writes'.format(
table_name, gsi_name, reads, writes))
# Return if dry-run
if get_global_option('dry_run'):
return
try:
DYNAMODB_CONNECTION.update_table(table_name=table_name,
global_secondary_index_updates=[{
"Update": {
"IndexName": gsi_name,
"ProvisionedThroughput": {
"ReadCapacityUnits":
reads,
"WriteCapacityUnits":
writes
}
}
}])
message = ('{0} - GSI: {1} - Provisioning updated to '
'{2} reads and {3} writes').format(table_name, gsi_name,
reads, writes)
# See if we should send notifications for scale-down, scale-up or both
sns_message_types = []
if current_reads > reads or current_writes > current_writes:
sns_message_types.append('scale-down')
if current_reads < reads or current_writes < current_writes:
sns_message_types.append('scale-up')
sns.publish_gsi_notification(
table_key,
gsi_key,
message,
sns_message_types,
subject='Updated provisioning for GSI {0}'.format(gsi_name))
except JSONResponseError as error:
exception = error.body['__type'].split('#')[1]
know_exceptions = ['LimitExceededException']
if exception in know_exceptions:
logger.warning('{0} - GSI: {1} - {2}: {3}'.format(
table_name, gsi_name, exception, error.body['message']))
else:
logger.error(
('{0} - GSI: {1} - Unhandled exception: {2}: {3}. '
'Please file a bug report at '
'https://github.com/sebdah/dynamic-dynamodb/issues').format(
table_name, gsi_name, exception, error.body['message']))
if (not retry_with_only_increase
and exception == 'LimitExceededException'):
logger.info('{0} - GSI: {1} - Will retry to update provisioning '
'with only increases'.format(table_name, gsi_name))
update_gsi_provisioning(table_name,
table_key,
gsi_name,
gsi_key,
reads,
writes,
retry_with_only_increase=True)
def __ensure_provisioning_alarm(table_name, table_key, gsi_name, gsi_key):
""" Ensure that provisioning alarm threshold is not exceeded
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
"""
consumed_read_units_percent = gsi_stats.get_consumed_read_units_percent(table_name, gsi_name)
consumed_write_units_percent = gsi_stats.get_consumed_write_units_percent(table_name, gsi_name)
reads_upper_alarm_threshold = get_gsi_option(table_key, gsi_key, "reads-upper-alarm-threshold")
reads_lower_alarm_threshold = get_gsi_option(table_key, gsi_key, "reads-lower-alarm-threshold")
writes_upper_alarm_threshold = get_gsi_option(table_key, gsi_key, "writes-upper-alarm-threshold")
writes_lower_alarm_threshold = get_gsi_option(table_key, gsi_key, "writes-lower-alarm-threshold")
# Check upper alarm thresholds
upper_alert_triggered = False
upper_alert_message = []
if reads_upper_alarm_threshold > 0 and consumed_read_units_percent >= reads_upper_alarm_threshold:
upper_alert_triggered = True
upper_alert_message.append(
"{0} - GSI: {1} - Consumed Read Capacity {2:d}% "
"was greater than or equal to the upper alarm "
"threshold {3:d}%\n".format(table_name, gsi_name, consumed_read_units_percent, reads_upper_alarm_threshold)
)
if writes_upper_alarm_threshold > 0 and consumed_write_units_percent >= writes_upper_alarm_threshold:
upper_alert_triggered = True
upper_alert_message.append(
"{0} - GSI: {1} - Consumed Write Capacity {2:d}% "
"was greater than or equal to the upper alarm "
"threshold {3:d}%\n".format(
table_name, gsi_name, consumed_write_units_percent, writes_upper_alarm_threshold
)
)
# Check lower alarm thresholds
lower_alert_triggered = False
lower_alert_message = []
if reads_lower_alarm_threshold > 0 and consumed_read_units_percent < reads_lower_alarm_threshold:
lower_alert_triggered = True
lower_alert_message.append(
"{0} - GSI: {1} - Consumed Read Capacity {2:d}% "
"was below the lower alarm threshold {3:d}%\n".format(
table_name, gsi_name, consumed_read_units_percent, reads_lower_alarm_threshold
)
)
if writes_lower_alarm_threshold > 0 and consumed_write_units_percent < writes_lower_alarm_threshold:
lower_alert_triggered = True
lower_alert_message.append(
"{0} - GSI: {1} - Consumed Write Capacity {2:d}% "
"was below the lower alarm threshold {3:d}%\n".format(
table_name, gsi_name, consumed_write_units_percent, writes_lower_alarm_threshold
)
)
# Send alert if needed
if upper_alert_triggered:
logger.info("{0} - GSI: {1} - Will send high provisioning alert".format(table_name, gsi_name))
sns.publish_gsi_notification(
table_key,
gsi_key,
"".join(upper_alert_message),
["high-throughput-alarm"],
subject="ALARM: High Throughput for Table {0} - GSI: {1}".format(table_name, gsi_name),
)
elif lower_alert_triggered:
logger.info("{0} - GSI: {1} - Will send low provisioning alert".format(table_name, gsi_name))
sns.publish_gsi_notification(
table_key,
gsi_key,
"".join(lower_alert_message),
["low-throughput-alarm"],
subject="ALARM: Low Throughput for Table {0} - GSI: {1}".format(table_name, gsi_name),
)
else:
logger.debug("{0} - GSI: {1} - Throughput alarm thresholds not crossed".format(table_name, gsi_name))
def __ensure_provisioning_reads(
table_name, table_key, gsi_name, gsi_key, num_consec_read_checks):
""" Ensure that provisioning is correct
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:type num_consec_read_checks: int
:param num_consec_read_checks: How many consecutive checks have we had
:returns: (bool, int, int)
update_needed, updated_read_units, num_consec_read_checks
"""
if not get_gsi_option(table_key, gsi_key, 'enable_reads_autoscaling'):
logger.info(
'{0} - GSI: {1} - '
'Autoscaling of reads has been disabled'.format(
table_name, gsi_name))
return False, dynamodb.get_provisioned_gsi_read_units(
table_name, gsi_name), 0
update_needed = False
try:
lookback_window_start = get_gsi_option(
table_key, gsi_key, 'lookback_window_start')
current_read_units = dynamodb.get_provisioned_gsi_read_units(
table_name, gsi_name)
consumed_read_units_percent = \
gsi_stats.get_consumed_read_units_percent(
table_name, gsi_name, lookback_window_start)
throttled_read_count = \
gsi_stats.get_throttled_read_event_count(
table_name, gsi_name, lookback_window_start)
reads_upper_threshold = \
get_gsi_option(table_key, gsi_key, 'reads_upper_threshold')
reads_lower_threshold = \
get_gsi_option(table_key, gsi_key, 'reads_lower_threshold')
increase_reads_unit = \
get_gsi_option(table_key, gsi_key, 'increase_reads_unit')
decrease_reads_unit = \
get_gsi_option(table_key, gsi_key, 'decrease_reads_unit')
increase_reads_with = \
get_gsi_option(table_key, gsi_key, 'increase_reads_with')
decrease_reads_with = \
get_gsi_option(table_key, gsi_key, 'decrease_reads_with')
throttled_reads_upper_threshold = \
get_gsi_option(
table_key, gsi_key, 'throttled_reads_upper_threshold')
max_provisioned_reads = \
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads')
num_read_checks_before_scale_down = \
get_gsi_option(
table_key, gsi_key, 'num_read_checks_before_scale_down')
num_read_checks_reset_percent = \
get_gsi_option(table_key, gsi_key, 'num_read_checks_reset_percent')
except JSONResponseError:
raise
except BotoServerError:
raise
# Set the updated units to the current read unit value
updated_read_units = current_read_units
# Reset consecutive reads if num_read_checks_reset_percent is reached
if num_read_checks_reset_percent:
if consumed_read_units_percent >= num_read_checks_reset_percent:
logger.info(
'{0} - GSI: {1} - Resetting the number of consecutive '
'read checks. Reason: Consumed percent {2} is '
'greater than reset percent: {3}'.format(
table_name,
gsi_name,
consumed_read_units_percent,
num_read_checks_reset_percent))
num_consec_read_checks = 0
if (consumed_read_units_percent == 0 and not
get_gsi_option(
table_key,
gsi_key,
'allow_scaling_down_reads_on_0_percent')):
logger.info(
'{0} - GSI: {1} - '
'Scaling down reads is not done when usage is at 0%'.format(
table_name, gsi_name))
# Increase needed due to high CU consumption
elif consumed_read_units_percent >= reads_upper_threshold:
# Exit if up scaling has been disabled
if not get_gsi_option(table_key, gsi_key, 'enable_reads_up_scaling'):
logger.debug(
'{0} - GSI: {1} - Up scaling event detected. '
'No action taken as scaling '
'up reads has been disabled in the configuration'.format(
table_name, gsi_name))
else:
if increase_reads_unit == 'percent':
calculated_provisioning = calculators.increase_reads_in_percent(
current_read_units,
increase_reads_with,
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calculated_provisioning = calculators.increase_reads_in_units(
current_read_units,
increase_reads_with,
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_read_units != calculated_provisioning:
logger.info(
'{0} - Resetting the number of consecutive '
'read checks. Reason: scale up event detected'.format(
table_name))
num_consec_read_checks = 0
update_needed = True
updated_read_units = calculated_provisioning
# Increase needed due to high throttling
elif throttled_read_count > throttled_reads_upper_threshold:
if throttled_reads_upper_threshold > 0:
if increase_reads_unit == 'percent':
calculated_provisioning = calculators.increase_reads_in_percent(
current_read_units,
increase_reads_with,
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calculated_provisioning = calculators.increase_reads_in_units(
current_read_units,
increase_reads_with,
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_read_units != calculated_provisioning:
logger.info(
'{0} - GSI: {1} - Resetting the number of consecutive '
'read checks. Reason: scale up event detected'.format(
table_name, gsi_name))
num_consec_read_checks = 0
update_needed = True
updated_read_units = calculated_provisioning
# Decrease needed due to low CU consumption
elif consumed_read_units_percent <= reads_lower_threshold:
# Exit if down scaling has been disabled
if not get_gsi_option(table_key, gsi_key, 'enable_reads_down_scaling'):
logger.debug(
'{0} - GSI: {1} - Down scaling event detected. '
'No action taken as scaling '
'down reads has been disabled in the configuration'.format(
table_name, gsi_name))
else:
if decrease_reads_unit == 'percent':
calculated_provisioning = calculators.decrease_reads_in_percent(
current_read_units,
decrease_reads_with,
get_gsi_option(table_key, gsi_key, 'min_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calculated_provisioning = calculators.decrease_reads_in_units(
current_read_units,
decrease_reads_with,
get_gsi_option(table_key, gsi_key, 'min_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_read_units != calculated_provisioning:
# We need to look at how many times the num_consec_read_checks
# integer has incremented and Compare to config file value
num_consec_read_checks = num_consec_read_checks + 1
if num_consec_read_checks >= num_read_checks_before_scale_down:
update_needed = True
updated_read_units = calculated_provisioning
# Never go over the configured max provisioning
if max_provisioned_reads:
if int(updated_read_units) > int(max_provisioned_reads):
update_needed = True
updated_read_units = int(max_provisioned_reads)
logger.info(
'Will not increase writes over gsi-max-provisioned-reads '
'limit ({0} writes)'.format(updated_read_units))
logger.info('{0} - GSI: {1} - Consecutive read checks {2}/{3}'.format(
table_name,
gsi_name,
num_consec_read_checks,
num_read_checks_before_scale_down))
return update_needed, updated_read_units, num_consec_read_checks
def __ensure_provisioning_writes(table_name, table_key, gsi_name, gsi_key,
num_consec_write_checks):
""" Ensure that provisioning of writes is correct
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:type num_consec_write_checks: int
:param num_consec_write_checks: How many consecutive checks have we had
:returns: (bool, int, int)
update_needed, updated_write_units, num_consec_write_checks
"""
if not get_gsi_option(table_key, gsi_key, 'enable_writes_autoscaling'):
logger.info('{0} - GSI: {1} - '
'Autoscaling of writes has been disabled'.format(
table_name, gsi_name))
return False, dynamodb.get_provisioned_gsi_write_units(
table_name, gsi_name), 0
update_needed = False
try:
lookback_window_start = get_gsi_option(table_key, gsi_key,
'lookback_window_start')
current_write_units = dynamodb.get_provisioned_gsi_write_units(
table_name, gsi_name)
consumed_write_units_percent = \
gsi_stats.get_consumed_write_units_percent(
table_name, gsi_name, lookback_window_start)
throttled_write_count = \
gsi_stats.get_throttled_write_event_count(
table_name, gsi_name, lookback_window_start)
writes_upper_threshold = \
get_gsi_option(table_key, gsi_key, 'writes_upper_threshold')
writes_lower_threshold = \
get_gsi_option(table_key, gsi_key, 'writes_lower_threshold')
throttled_writes_upper_threshold = \
get_gsi_option(
table_key, gsi_key, 'throttled_writes_upper_threshold')
increase_writes_unit = \
get_gsi_option(table_key, gsi_key, 'increase_writes_unit')
increase_writes_with = \
get_gsi_option(table_key, gsi_key, 'increase_writes_with')
decrease_writes_unit = \
get_gsi_option(table_key, gsi_key, 'decrease_writes_unit')
decrease_writes_with = \
get_gsi_option(table_key, gsi_key, 'decrease_writes_with')
max_provisioned_writes = \
get_gsi_option(table_key, gsi_key, 'max_provisioned_writes')
num_write_checks_before_scale_down = \
get_gsi_option(
table_key, gsi_key, 'num_write_checks_before_scale_down')
num_write_checks_reset_percent = \
get_gsi_option(table_key, gsi_key, 'num_write_checks_reset_percent')
except JSONResponseError:
raise
except BotoServerError:
raise
# Set the updated units to the current write unit value
updated_write_units = current_write_units
# Reset write consecutive count if num_write_checks_reset_percent is reached
if num_write_checks_reset_percent:
if consumed_write_units_percent >= num_write_checks_reset_percent:
logger.info('{0} - GSI: {1} - Resetting the number of consecutive '
'write checks. Reason: Consumed percent {2} is '
'greater than reset percent: {3}'.format(
table_name, gsi_name, consumed_write_units_percent,
num_write_checks_reset_percent))
num_consec_write_checks = 0
# Check if we should update write provisioning
if (consumed_write_units_percent == 0 and not get_gsi_option(
table_key, gsi_key, 'allow_scaling_down_writes_on_0_percent')):
logger.info(
'{0} - GSI: {1} - '
'Scaling down writes is not done when usage is at 0%'.format(
table_name, gsi_name))
# Increase needed due to high CU consumption
elif consumed_write_units_percent >= writes_upper_threshold:
# Exit if up scaling has been disabled
if not get_gsi_option(table_key, gsi_key, 'enable_writes_up_scaling'):
logger.debug(
'{0} - GSI: {1} - Up scaling event detected. '
'No action taken as scaling '
'up writes has been disabled in the configuration'.format(
table_name, gsi_name))
else:
if increase_writes_unit == 'percent':
calculated_provisioning = \
calculators.increase_writes_in_percent(
current_write_units,
increase_writes_with,
get_gsi_option(
table_key, gsi_key, 'max_provisioned_writes'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calculated_provisioning = calculators.increase_writes_in_units(
current_write_units, increase_writes_with,
get_gsi_option(table_key, gsi_key,
'max_provisioned_writes'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_write_units != calculated_provisioning:
logger.info(
'{0} - GSI: {1} - Resetting the number of consecutive '
'write checks. Reason: scale up event detected'.format(
table_name, gsi_name))
num_consec_write_checks = 0
update_needed = True
updated_write_units = calculated_provisioning
# Increase needed due to high throttling
elif throttled_write_count > throttled_writes_upper_threshold:
if throttled_writes_upper_threshold > 0:
if increase_writes_unit == 'percent':
calculated_provisioning = \
calculators.increase_writes_in_percent(
current_write_units,
increase_writes_with,
get_gsi_option(
table_key, gsi_key, 'max_provisioned_writes'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calculated_provisioning = calculators.increase_writes_in_units(
current_write_units, increase_writes_with,
get_gsi_option(table_key, gsi_key,
'max_provisioned_writes'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_write_units != calculated_provisioning:
logger.info(
'{0} - GSI: {1} - Resetting the number of consecutive '
'write checks. Reason: scale up event detected'.format(
table_name, gsi_name))
num_consec_write_checks = 0
update_needed = True
updated_write_units = calculated_provisioning
# Decrease needed due to low CU consumption
elif consumed_write_units_percent <= writes_lower_threshold:
# Exit if down scaling has been disabled
if not get_gsi_option(table_key, gsi_key,
'enable_writes_down_scaling'):
logger.debug(
'{0} - GSI: {1} - Down scaling event detected. '
'No action taken as scaling '
'down writes has been disabled in the configuration'.format(
table_name, gsi_name))
else:
if decrease_writes_unit == 'percent':
calculated_provisioning = \
calculators.decrease_writes_in_percent(
current_write_units,
decrease_writes_with,
get_gsi_option(
table_key, gsi_key, 'min_provisioned_writes'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calculated_provisioning = calculators.decrease_writes_in_units(
current_write_units, decrease_writes_with,
get_gsi_option(table_key, gsi_key,
'min_provisioned_writes'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_write_units != calculated_provisioning:
num_consec_write_checks = num_consec_write_checks + 1
if (num_consec_write_checks >=
num_write_checks_before_scale_down):
update_needed = True
updated_write_units = calculated_provisioning
# Never go over the configured max provisioning
if max_provisioned_writes:
if int(updated_write_units) > int(max_provisioned_writes):
update_needed = True
updated_write_units = int(max_provisioned_writes)
logger.info(
'{0} - GSI: {1} - '
'Will not increase writes over gsi-max-provisioned-writes '
'limit ({2} writes)'.format(table_name, gsi_name,
updated_write_units))
logger.info('{0} - GSI: {1} - Consecutive write checks {2}/{3}'.format(
table_name, gsi_name, num_consec_write_checks,
num_write_checks_before_scale_down))
return update_needed, updated_write_units, num_consec_write_checks
def __ensure_provisioning_writes(
table_name, table_key, gsi_name, gsi_key, num_consec_write_checks):
""" Ensure that provisioning of writes is correct
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:type num_consec_write_checks: int
:param num_consec_write_checks: How many consecutive checks have we had
:returns: (bool, int, int)
update_needed, updated_write_units, num_consec_write_checks
"""
if not get_gsi_option(table_key, gsi_key, 'enable_writes_autoscaling'):
logger.info(
'{0} - GSI: {1} - '
'Autoscaling of writes has been disabled'.format(
table_name, gsi_name))
return False, dynamodb.get_provisioned_gsi_write_units(
table_name, gsi_name), 0
update_needed = False
try:
current_write_units = dynamodb.get_provisioned_gsi_write_units(
table_name, gsi_name)
consumed_write_units_percent = \
gsi_stats.get_consumed_write_units_percent(table_name, gsi_name)
throttled_write_count = \
gsi_stats.get_throttled_write_event_count(table_name, gsi_name)
writes_upper_threshold = \
get_gsi_option(table_key, gsi_key, 'writes_upper_threshold')
writes_lower_threshold = \
get_gsi_option(table_key, gsi_key, 'writes_lower_threshold')
throttled_writes_upper_threshold = \
get_gsi_option(
table_key, gsi_key, 'throttled_writes_upper_threshold')
increase_writes_unit = \
get_gsi_option(table_key, gsi_key, 'increase_writes_unit')
increase_writes_with = \
get_gsi_option(table_key, gsi_key, 'increase_writes_with')
decrease_writes_unit = \
get_gsi_option(table_key, gsi_key, 'decrease_writes_unit')
decrease_writes_with = \
get_gsi_option(table_key, gsi_key, 'decrease_writes_with')
max_provisioned_writes = \
get_gsi_option(table_key, gsi_key, 'max_provisioned_writes')
num_write_checks_before_scale_down = \
get_gsi_option(
table_key, gsi_key, 'num_write_checks_before_scale_down')
num_write_checks_reset_percent = \
get_gsi_option(key_name, 'num_write_checks_reset_percent')
except JSONResponseError:
raise
except BotoServerError:
raise
# Set the updated units to the current write unit value
updated_write_units = current_write_units
# Check if we should update write provisioning
if (consumed_write_units_percent == 0 and not get_gsi_option(
table_key, gsi_key, 'allow_scaling_down_writes_on_0_percent')):
logger.info(
'{0} - GSI: {1} - '
'Scaling down writes is not done when usage is at 0%'.format(
table_name, gsi_name))
elif consumed_write_units_percent >= writes_upper_threshold:
if increase_writes_unit == 'percent':
calulated_provisioning = calculators.increase_writes_in_percent(
current_write_units,
increase_writes_with,
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calulated_provisioning = calculators.increase_writes_in_units(
current_write_units,
increase_writes_with,
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_write_units != calulated_provisioning:
logger.info(
'{0} - Resetting the number of consecutive '
'write checks. Reason: scale up event detected'.format(
table_name))
num_consec_write_checks = 0
update_needed = True
updated_write_units = calulated_provisioning
elif throttled_write_count > throttled_writes_upper_threshold:
if throttled_writes_upper_threshold > 0:
if increase_writes_unit == 'percent':
calulated_provisioning = calculators.increase_writes_in_percent(
current_write_units,
increase_writes_with,
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calulated_provisioning = calculators.increase_writes_in_units(
current_write_units,
increase_writes_with,
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_write_units != calulated_provisioning:
logger.info(
'{0} - Resetting the number of consecutive '
'write checks. Reason: scale up event detected'.format(
table_name))
num_consec_write_checks = 0
update_needed = True
updated_write_units = calulated_provisioning
elif consumed_write_units_percent >= num_write_checks_reset_percent:
logger.info(
'{0} - Resetting the number of consecutive '
'write checks. Reason: Consumed Percent {1} is Greater than Reset Percent: {2}'.format(
table_name, consumed_write_units_percent, num_write_checks_reset_percent))
num_consec_write_checks = 0
elif consumed_write_units_percent <= writes_lower_threshold:
if decrease_writes_unit == 'percent':
calulated_provisioning = calculators.decrease_writes_in_percent(
current_write_units,
decrease_writes_with,
get_gsi_option(table_key, gsi_key, 'min_provisioned_writes'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calulated_provisioning = calculators.decrease_writes_in_units(
current_write_units,
decrease_writes_with,
get_gsi_option(table_key, gsi_key, 'min_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_write_units != calulated_provisioning:
num_consec_write_checks = num_consec_write_checks + 1
if num_consec_write_checks >= num_write_checks_before_scale_down:
update_needed = True
updated_write_units = calulated_provisioning
if max_provisioned_writes:
if int(updated_write_units) > int(max_provisioned_writes):
update_needed = True
updated_write_units = int(max_provisioned_writes)
logger.info(
'{0} - GSI: {1} - '
'Will not increase writes over gsi-max-provisioned-writes '
'limit ({2} writes)'.format(
table_name,
gsi_name,
updated_write_units))
logger.info('{0} - Consecutive write checks {1}/{2}'.format(
table_name,
num_consec_write_checks,
num_write_checks_before_scale_down))
return update_needed, updated_write_units, num_consec_write_checks
def __ensure_provisioning_reads(table_name, table_key, gsi_name, gsi_key,
num_consec_read_checks):
""" Ensure that provisioning is correct
:type table_name: str
:param table_name: Name of the DynamoDB table
:type table_key: str
:param table_key: Table configuration option key name
:type gsi_name: str
:param gsi_name: Name of the GSI
:type gsi_key: str
:param gsi_key: Configuration option key name
:type num_consec_read_checks: int
:param num_consec_read_checks: How many consecutive checks have we had
:returns: (bool, int, int)
update_needed, updated_read_units, num_consec_read_checks
"""
if not get_gsi_option(table_key, gsi_key, 'enable_reads_autoscaling'):
logger.info('{0} - GSI: {1} - '
'Autoscaling of reads has been disabled'.format(
table_name, gsi_name))
return False, dynamodb.get_provisioned_gsi_read_units(
table_name, gsi_name), 0
update_needed = False
try:
current_read_units = dynamodb.get_provisioned_gsi_read_units(
table_name, gsi_name)
consumed_read_units_percent = \
gsi_stats.get_consumed_read_units_percent(table_name, gsi_name)
throttled_read_count = \
gsi_stats.get_throttled_read_event_count(table_name, gsi_name)
reads_upper_threshold = \
get_gsi_option(table_key, gsi_key, 'reads_upper_threshold')
reads_lower_threshold = \
get_gsi_option(table_key, gsi_key, 'reads_lower_threshold')
increase_reads_unit = \
get_gsi_option(table_key, gsi_key, 'increase_reads_unit')
decrease_reads_unit = \
get_gsi_option(table_key, gsi_key, 'decrease_reads_unit')
increase_reads_with = \
get_gsi_option(table_key, gsi_key, 'increase_reads_with')
decrease_reads_with = \
get_gsi_option(table_key, gsi_key, 'decrease_reads_with')
throttled_reads_upper_threshold = \
get_gsi_option(
table_key, gsi_key, 'throttled_reads_upper_threshold')
max_provisioned_reads = \
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads')
num_read_checks_before_scale_down = \
get_gsi_option(
table_key, gsi_key, 'num_read_checks_before_scale_down')
num_read_checks_reset_percent = \
get_gsi_option(key_name, 'num_read_checks_reset_percent')
except JSONResponseError:
raise
except BotoServerError:
raise
# Set the updated units to the current read unit value
updated_read_units = current_read_units
if (consumed_read_units_percent == 0 and not get_gsi_option(
table_key, gsi_key, 'allow_scaling_down_reads_on_0_percent')):
logger.info(
'{0} - GSI: {1} - '
'Scaling down reads is not done when usage is at 0%'.format(
table_name, gsi_name))
elif consumed_read_units_percent >= reads_upper_threshold:
if increase_reads_unit == 'percent':
calulated_provisioning = calculators.increase_reads_in_percent(
current_read_units, increase_reads_with,
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calulated_provisioning = calculators.increase_reads_in_units(
current_read_units, increase_reads_with,
get_gsi_option(table_key, gsi_key, 'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_read_units != calulated_provisioning:
logger.info('{0} - Resetting the number of consecutive '
'read checks. Reason: scale up event detected'.format(
table_name))
num_consec_read_checks = 0
update_needed = True
updated_read_units = calulated_provisioning
elif throttled_read_count > throttled_reads_upper_threshold:
if throttled_reads_upper_threshold > 0:
if increase_reads_unit == 'percent':
calulated_provisioning = calculators.increase_reads_in_percent(
current_read_units, increase_reads_with,
get_gsi_option(table_key, gsi_key,
'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calulated_provisioning = calculators.increase_reads_in_units(
current_read_units, increase_reads_with,
get_gsi_option(table_key, gsi_key,
'max_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_read_units != calulated_provisioning:
logger.info(
'{0} - Resetting the number of consecutive '
'read checks. Reason: scale up event detected'.format(
table_name))
num_consec_read_checks = 0
update_needed = True
updated_read_units = calulated_provisioning
elif consumed_read_units_percent >= num_read_checks_reset_percent:
logger.info(
'{0} - Resetting the number of consecutive '
'read checks. Reason: Consumed Percent {1} is Greater than Reset Percent: {2}'
.format(table_name, consumed_read_units_percent,
num_read_checks_reset_percent))
num_consec_read_checks = 0
elif consumed_read_units_percent <= reads_lower_threshold:
if decrease_reads_unit == 'percent':
calulated_provisioning = calculators.decrease_reads_in_percent(
current_read_units, decrease_reads_with,
get_gsi_option(table_key, gsi_key, 'min_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
else:
calulated_provisioning = calculators.decrease_reads_in_units(
current_read_units, decrease_reads_with,
get_gsi_option(table_key, gsi_key, 'min_provisioned_reads'),
'{0} - GSI: {1}'.format(table_name, gsi_name))
if current_read_units != calulated_provisioning:
# We need to look at how many times the num_consec_read_checks
# integer has incremented and Compare to config file value
num_consec_read_checks = num_consec_read_checks + 1
if num_consec_read_checks >= num_read_checks_before_scale_down:
update_needed = True
updated_read_units = calulated_provisioning
if max_provisioned_reads:
if int(updated_read_units) > int(max_provisioned_reads):
update_needed = True
updated_read_units = int(max_provisioned_reads)
logger.info(
'Will not increase writes over gsi-max-provisioned-reads '
'limit ({0} writes)'.format(updated_read_units))
logger.info('{0} - Consecutive read checks {1}/{2}'.format(
table_name, num_consec_read_checks, num_read_checks_before_scale_down))
return update_needed, updated_read_units, num_consec_read_checks