Merge "Add more backoff functions"

doc/source/user/notification_delivery_policy.rst

@@ -46,7 +46,8 @@ Webhook
 -  'minimum_delay' and 'maximum_delay' mean delay time in seconds.
 -  'retry_backoff_function' mean name of retry backoff function.
    There will be a enum in Zaqar that contain all valid values.
-   At first step, Zaqar only supports one function: 'linear'.
+   Zaqar now supports retry backoff function including 'linear',
+   'arithmetic','geometric' and 'exponential'.
 -  'minimum_delay_retries' and 'maximum_delay_retries' mean the number of
    retries with 'minimum_delay' or 'maximum_delay' delay time.
 

releasenotes/notes/support-more-backoff-functions-41e02a5977341576.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - Support more retry backoff function in webhook type. It will work
+    when Zaqar failed to send the notification to the subscriber.
+    Users can define the retry backoff function in metadata of queue.
+    There are four retry backoff functions including  'linear',
+    'arithmetic', 'geometric' and 'exponential'.

zaqar/notification/tasks/webhook.py

@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import math
 import time
 
 import json
@@ -27,7 +28,33 @@ LOG = logging.getLogger(__name__)
 def _Linear_function(minimum_delay, maximum_delay, times):
     return range(minimum_delay, maximum_delay, times)
 
-RETRY_BACKOFF_FUNCTION_MAP = {'linear': _Linear_function}
+
+def _Geometric_function(minimum_delay, maximum_delay, times):
+    x_max = int((maximum_delay - minimum_delay) / times)
+    k = math.pow(10, math.log10(maximum_delay/minimum_delay)/(x_max-1))
+    xarray = range(1, x_max+1)
+    return [int(minimum_delay*math.pow(k, a-1)) for a in xarray]
+
+
+def _Exponential_function(minimum_delay, maximum_delay, times):
+    x_max = int((maximum_delay - minimum_delay) / times)
+    k = math.pow(10, math.log10(maximum_delay/minimum_delay)/(x_max-1))
+    p = minimum_delay/k
+    xarray = range(1, x_max+1)
+    return [int(p*math.pow(k, a)) for a in xarray]
+
+
+def _Arithmetic_function(minimum_delay, maximum_delay, times):
+    x_max = int((maximum_delay - minimum_delay) / times)
+    d = 2.0 * (maximum_delay - minimum_delay) / (x_max * (x_max - 1))
+    xarray = range(1, x_max+1)
+    return [int(minimum_delay+(a-1)*a*d/2) for a in xarray]
+
+
+RETRY_BACKOFF_FUNCTION_MAP = {'linear': _Linear_function,
+                              'arithmetic': _Arithmetic_function,
+                              'geometric': _Geometric_function,
+                              'exponential': _Exponential_function}
 
 
 class WebhookTask(object):
@@ -65,9 +92,8 @@ class WebhookTask(object):
             time.sleep(retry_policy.get('minimum_delay', consts.MINIMUM_DELAY))
             if self._post_request_success(subscriber, data, headers):
                 return
-        # Backoff Phase: Linear retry
-        # TODO(wanghao): Now we only support the linear function, we should
-        # support more in Queens.
+        # Now we support linear,arithmetic,
+        # exponential and geometric retry backoff function.
         retry_function = retry_policy.get('retry_backoff_function', 'linear')
         backoff_function = RETRY_BACKOFF_FUNCTION_MAP[retry_function]
         for i in backoff_function(retry_policy.get('minimum_delay',
@@ -75,8 +101,8 @@ class WebhookTask(object):
                                   retry_policy.get('maximum_delay',
                                                    consts.MAXIMUM_DELAY),
                                   consts.LINEAR_INTERVAL):
-            LOG.debug('Retry with retry_backoff_function, sleep: %s seconds',
-                      i)
+            LOG.debug('Retry with function:%s, sleep: %s seconds',
+                      retry_function, i)
             time.sleep(i)
             if self._post_request_success(subscriber, data, headers):
                 return

zaqar/tests/unit/notification/test_notifier.py

@@ -21,6 +21,7 @@ import mock
 
 from zaqar.common import urls
 from zaqar.notification import notifier
+from zaqar.notification.tasks import webhook
 from zaqar import tests as testing
 
 
@@ -433,3 +434,16 @@ class NotifierTest(testing.TestBase):
     @ddt.data(False, True)
     def test_send_confirm_notification_with_email(self, is_unsub):
         self._send_confirm_notification_with_email(is_unsubscribed=is_unsub)
+
+    def test_webhook_backoff_function(self):
+        expect = [10, 12, 14, 18, 22, 27, 33, 40, 49, 60]
+        sec = webhook._Exponential_function(10, 60, 5)
+        self.assertEqual(expect, sec)
+
+        expect = [20, 22, 25, 29, 33, 37, 42, 48, 54, 62, 70, 80]
+        sec = webhook._Geometric_function(20, 80, 5)
+        self.assertEqual(expect, sec)
+
+        expect = [30, 30, 32, 34, 37, 41, 46, 51, 57, 64, 72, 80, 90, 100]
+        sec = webhook._Arithmetic_function(30, 100, 5)
+        self.assertEqual(expect, sec)

zaqar/transport/validation.py

@@ -21,8 +21,10 @@ from oslo_config import cfg
 from oslo_utils import timeutils
 import six
 
+from zaqar.common import consts
 from zaqar.i18n import _
 
+
 MIN_MESSAGE_TTL = 60
 MIN_CLAIM_TTL = 60
 MIN_CLAIM_GRACE = 60
@@ -249,11 +251,11 @@ class Validator(object):
                     if retry_value and not isinstance(retry_value, str):
                         msg = _('retry_backoff_function must be a string.')
                         raise ValidationFailed(msg)
-                    # TODO(wanghao): Now we only support linear function.
-                    # This will be removed after we support more functions.
-                    if retry_value and retry_value != 'linear':
-                        msg = _('retry_backoff_function only supports linear '
-                                'now.')
+                    # Now we support linear, arithmetic, exponential
+                    # and geometric retry backoff function.
+                    fun = {'linear', 'arithmetic', 'exponential', 'geometric'}
+                    if retry_value and retry_value not in fun:
+                        msg = _('invalid retry_backoff_function.')
                         raise ValidationFailed(msg)
                 elif key == 'ignore_subscription_override':
                     if retry_value and not isinstance(retry_value, bool):
@@ -264,6 +266,16 @@ class Validator(object):
                     if retry_value and not isinstance(retry_value, int):
                         msg = _('Retry policy: %s must be a integer.') % key
                         raise ValidationFailed(msg)
+            min_delay = retry_policy.get('minimum_delay',
+                                         consts.MINIMUM_DELAY)
+            max_delay = retry_policy.get('maximum_delay',
+                                         consts.MAXIMUM_DELAY)
+            if max_delay < min_delay:
+                msg = _('minimum_delay must less than maximum_delay.')
+                raise ValidationFailed(msg)
+            if ((max_delay - min_delay) < 2*consts.LINEAR_INTERVAL):
+                msg = _('invalid minimum_delay and maximum_delay.')
+                raise ValidationFailed(msg)
 
     def queue_patching(self, request, changes):
         washed_changes = []