Source code for heat.engine.sync_point

# 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
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# 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__)


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 update_input_data(context, entity_id, current_traversal, is_update, atomic_key, input_data): rows_updated = sync_point_object.SyncPoint.update_input_data( context, entity_id, current_traversal, is_update, atomic_key, input_data) return rows_updated
[docs]def str_pack_tuple(t): return u'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(u'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 deserialize_input_data(db_input_data): db_input_data = db_input_data.get('input_data') if not db_input_data: return {} return dict(_deserialize(db_input_data))
[docs]def serialize_input_data(input_data): return {'input_data': _serialize(input_data)}
[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))