#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import ast
import tenacity
from oslo_log import log as logging
from heat.common import exception
from heat.objects import sync_point as sync_point_object
LOG = logging.getLogger(__name__)
KEY_SEPERATOR = ':'
def _dump_list(items, separator=', '):
return separator.join(map(str, items))
[docs]
def make_key(*components):
assert len(components) >= 2
return _dump_list(components, KEY_SEPERATOR)
[docs]
def create(context, entity_id, traversal_id, is_update, stack_id):
"""Creates a sync point entry in DB."""
values = {'entity_id': entity_id, 'traversal_id': traversal_id,
'is_update': is_update, 'atomic_key': 0,
'stack_id': stack_id, 'input_data': {}}
return sync_point_object.SyncPoint.create(context, values)
[docs]
def get(context, entity_id, traversal_id, is_update):
"""Retrieves a sync point entry from DB."""
sync_point = sync_point_object.SyncPoint.get_by_key(context, entity_id,
traversal_id,
is_update)
if sync_point is None:
key = (entity_id, traversal_id, is_update)
raise exception.EntityNotFound(entity='Sync Point', name=key)
return sync_point
[docs]
def delete_all(context, stack_id, traversal_id):
"""Deletes all sync points of a stack associated with a traversal_id."""
return sync_point_object.SyncPoint.delete_all_by_stack_and_traversal(
context, stack_id, traversal_id
)
[docs]
def str_pack_tuple(t):
return 'tuple:' + str(tuple(t))
def _str_unpack_tuple(s):
s = s[s.index(':') + 1:]
return ast.literal_eval(s)
def _deserialize(d):
d2 = {}
for k, v in d.items():
if isinstance(k, str) and k.startswith('tuple:('):
k = _str_unpack_tuple(k)
if isinstance(v, dict):
v = _deserialize(v)
d2[k] = v
return d2
def _serialize(d):
d2 = {}
for k, v in d.items():
if isinstance(k, tuple):
k = str_pack_tuple(k)
if isinstance(v, dict):
v = _serialize(v)
d2[k] = v
return d2
[docs]
def sync(cnxt, entity_id, current_traversal, is_update, propagate,
predecessors, new_data):
# Retry waits up to 60 seconds at most, with exponentially increasing
# amounts of jitter per resource still outstanding
wait_strategy = tenacity.wait_random_exponential(max=60)
def init_jitter(existing_input_data):
nconflicts = max(0, len(predecessors) - len(existing_input_data) - 1)
# 10ms per potential conflict, up to a max of 10s in total
return min(nconflicts, 1000) * 0.01
@tenacity.retry(
retry=tenacity.retry_if_result(lambda r: r is None),
wait=wait_strategy
)
def _sync():
sync_point = get(cnxt, entity_id, current_traversal, is_update)
input_data = deserialize_input_data(sync_point.input_data)
wait_strategy.multiplier = init_jitter(input_data)
input_data.update(new_data)
rows_updated = update_input_data(
cnxt, entity_id, current_traversal, is_update,
sync_point.atomic_key, serialize_input_data(input_data))
return input_data if rows_updated else None
input_data = _sync()
waiting = predecessors - set(input_data)
key = make_key(entity_id, current_traversal, is_update)
if waiting:
LOG.debug('[%s] Waiting %s: Got %s; still need %s',
key, entity_id, _dump_list(input_data), _dump_list(waiting))
else:
LOG.debug('[%s] Ready %s: Got %s',
key, entity_id, _dump_list(input_data))
propagate(entity_id, serialize_input_data(input_data))
