diff options
Diffstat (limited to 'openstack/common')
| -rw-r--r-- | openstack/common/periodic_task.py | 124 |
1 files changed, 98 insertions, 26 deletions
diff --git a/openstack/common/periodic_task.py b/openstack/common/periodic_task.py index 28ab22e..c48d8b9 100644 --- a/openstack/common/periodic_task.py +++ b/openstack/common/periodic_task.py @@ -13,26 +13,72 @@ # License for the specific language governing permissions and limitations # under the License. +import datetime +import time +from oslo.config import cfg + from openstack.common.gettextutils import _ from openstack.common import log as logging +from openstack.common import timeutils + + +periodic_opts = [ + cfg.BoolOpt('run_external_periodic_tasks', + default=True, + help=('Some periodic tasks can be run in a separate process. ' + 'Should we run them here?')), +] + +CONF = cfg.CONF +CONF.register_opts(periodic_opts) LOG = logging.getLogger(__name__) +DEFAULT_INTERVAL = 60.0 + + +class InvalidPeriodicTaskArg(Exception): + message = _("Unexpected argument for periodic task creation: %(arg)s.") + def periodic_task(*args, **kwargs): """Decorator to indicate that a method is a periodic task. This decorator can be used in two ways: - 1. Without arguments '@periodic_task', this will be run on every tick + 1. Without arguments '@periodic_task', this will be run on every cycle of the periodic scheduler. - 2. With arguments, @periodic_task(ticks_between_runs=N), this will be - run on every N ticks of the periodic scheduler. + 2. With arguments: + @periodic_task(spacing=N [, run_immediately=[True|False]]) + this will be run on approximately every N seconds. If this number is + negative the periodic task will be disabled. If the run_immediately + argument is provided and has a value of 'True', the first run of the + task will be shortly after task scheduler starts. If + run_immediately is omitted or set to 'False', the first time the + task runs will be approximately N seconds after the task scheduler + starts. """ def decorator(f): + # Test for old style invocation + if 'ticks_between_runs' in kwargs: + raise InvalidPeriodicTaskArg(arg='ticks_between_runs') + + # Control if run at all f._periodic_task = True - f._ticks_between_runs = kwargs.pop('ticks_between_runs', 0) + f._periodic_external_ok = kwargs.pop('external_process_ok', False) + if f._periodic_external_ok and not CONF.run_external_periodic_tasks: + f._periodic_enabled = False + else: + f._periodic_enabled = kwargs.pop('enabled', True) + + # Control frequency + f._periodic_spacing = kwargs.pop('spacing', 0) + f._periodic_immediate = kwargs.pop('run_immediately', False) + if f._periodic_immediate: + f._periodic_last_run = None + else: + f._periodic_last_run = timeutils.utcnow() return f # NOTE(sirp): The `if` is necessary to allow the decorator to be used with @@ -59,7 +105,7 @@ class _PeriodicTasksMeta(type): super(_PeriodicTasksMeta, cls).__init__(names, bases, dict_) # NOTE(sirp): if the attribute is not present then we must be the base - # class, so, go ahead and initialize it. If the attribute is present, + # class, so, go ahead an initialize it. If the attribute is present, # then we're a subclass so make a copy of it so we don't step on our # parent's toes. try: @@ -68,20 +114,39 @@ class _PeriodicTasksMeta(type): cls._periodic_tasks = [] try: - cls._ticks_to_skip = cls._ticks_to_skip.copy() + cls._periodic_last_run = cls._periodic_last_run.copy() except AttributeError: - cls._ticks_to_skip = {} + cls._periodic_last_run = {} + + try: + cls._periodic_spacing = cls._periodic_spacing.copy() + except AttributeError: + cls._periodic_spacing = {} - # This uses __dict__ instead of - # inspect.getmembers(cls, inspect.ismethod) so only the methods of the - # current class are added when this class is scanned, and base classes - # are not added redundantly. for value in cls.__dict__.values(): if getattr(value, '_periodic_task', False): task = value name = task.__name__ + + if task._periodic_spacing < 0: + LOG.info(_('Skipping periodic task %(task)s because ' + 'its interval is negative'), + {'task': name}) + continue + if not task._periodic_enabled: + LOG.info(_('Skipping periodic task %(task)s because ' + 'it is disabled'), + {'task': name}) + continue + + # A periodic spacing of zero indicates that this task should + # be run every pass + if task._periodic_spacing == 0: + task._periodic_spacing = None + cls._periodic_tasks.append((name, task)) - cls._ticks_to_skip[name] = task._ticks_between_runs + cls._periodic_spacing[name] = task._periodic_spacing + cls._periodic_last_run[name] = task._periodic_last_run class PeriodicTasks(object): @@ -89,27 +154,34 @@ class PeriodicTasks(object): def run_periodic_tasks(self, context, raise_on_error=False): """Tasks to be run at a periodic interval.""" + idle_for = DEFAULT_INTERVAL for task_name, task in self._periodic_tasks: full_task_name = '.'.join([self.__class__.__name__, task_name]) - ticks_to_skip = self._ticks_to_skip[task_name] - if ticks_to_skip > 0: - LOG.debug(_("Skipping %(full_task_name)s, %(ticks_to_skip)s" - " ticks left until next run"), - dict(full_task_name=full_task_name, - ticks_to_skip=ticks_to_skip)) - self._ticks_to_skip[task_name] -= 1 - continue + now = timeutils.utcnow() + spacing = self._periodic_spacing[task_name] + last_run = self._periodic_last_run[task_name] + + # If a periodic task is _nearly_ due, then we'll run it early + if spacing is not None and last_run is not None: + due = last_run + datetime.timedelta(seconds=spacing) + if not timeutils.is_soon(due, 0.2): + idle_for = min(idle_for, timeutils.delta_seconds(now, due)) + continue - self._ticks_to_skip[task_name] = task._ticks_between_runs - LOG.debug(_("Running periodic task %(full_task_name)s"), - dict(full_task_name=full_task_name)) + if spacing is not None: + idle_for = min(idle_for, spacing) + + LOG.debug(_("Running periodic task %(full_task_name)s"), locals()) + self._periodic_last_run[task_name] = timeutils.utcnow() try: task(self, context) except Exception as e: if raise_on_error: raise - LOG.exception(_("Error during %(full_task_name)s:" - " %(e)s"), - dict(e=e, full_task_name=full_task_name)) + LOG.exception(_("Error during %(full_task_name)s: %(e)s"), + locals()) + time.sleep(0) + + return idle_for |