Source code for heat.scaling.cooldown

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#         http://www.apache.org/licenses/LICENSE-2.0
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import datetime

from heat.common import exception
from heat.common.i18n import _
from heat.engine import resource
from oslo_log import log as logging
from oslo_utils import timeutils

LOG = logging.getLogger(__name__)


[docs]class CooldownMixin(object): """Utility class to encapsulate Cooldown related logic. This logic includes both cooldown timestamp comparing and scaling in progress checking. """ def _sanitize_cooldown(self, cooldown): if cooldown is None: return 0 return max(0, cooldown) def _check_scaling_allowed(self, cooldown): metadata = self.metadata_get() if metadata.get('scaling_in_progress'): LOG.info("Can not perform scaling action: resource %s " "is already in scaling.", self.name) reason = _('due to scaling activity') raise resource.NoActionRequired(res_name=self.name, reason=reason) cooldown = self._sanitize_cooldown(cooldown) # if both cooldown and cooldown_end not in metadata if all(k not in metadata for k in ('cooldown', 'cooldown_end')): # Note: this is for supporting old version cooldown checking metadata.pop('scaling_in_progress', None) if metadata and cooldown != 0: last_adjust = next(iter(metadata.keys())) if not timeutils.is_older_than(last_adjust, cooldown): self._log_and_raise_no_action(cooldown) elif 'cooldown_end' in metadata: cooldown_end = next(iter(metadata['cooldown_end'].keys())) now = timeutils.utcnow().isoformat() if now < cooldown_end: self._log_and_raise_no_action(cooldown) elif cooldown != 0: # Note: this is also for supporting old version cooldown checking last_adjust = next(iter(metadata['cooldown'].keys())) if not timeutils.is_older_than(last_adjust, cooldown): self._log_and_raise_no_action(cooldown) # Assumes _finished_scaling is called # after the scaling operation completes metadata['scaling_in_progress'] = True self.metadata_set(metadata) def _log_and_raise_no_action(self, cooldown): LOG.info("Can not perform scaling action: " "resource %(name)s is in cooldown (%(cooldown)s).", {'name': self.name, 'cooldown': cooldown}) reason = _('due to cooldown, ' 'cooldown %s') % cooldown raise resource.NoActionRequired( res_name=self.name, reason=reason) def _finished_scaling(self, cooldown, cooldown_reason, size_changed=True): # If we wanted to implement the AutoScaling API like AWS does, # we could maintain event history here, but since we only need # the latest event for cooldown, just store that for now metadata = self.metadata_get() if size_changed: cooldown = self._sanitize_cooldown(cooldown) cooldown_end = (timeutils.utcnow() + datetime.timedelta( seconds=cooldown)).isoformat() if 'cooldown_end' in metadata: cooldown_end = max( next(iter(metadata['cooldown_end'].keys())), cooldown_end) metadata['cooldown_end'] = {cooldown_end: cooldown_reason} metadata['scaling_in_progress'] = False try: self.metadata_set(metadata) except exception.NotFound: pass
[docs] def handle_metadata_reset(self): metadata = self.metadata_get() if 'scaling_in_progress' in metadata: metadata['scaling_in_progress'] = False self.metadata_set(metadata)