Add cleaning time

This patch adds a margin between the end of a lease and the start of the
next lease. The length of the margin can be configured with the new
configuration option 'cleaning_time'.

Note that it does not actually change start/end_lease time, but just
takes into account the margin when looking for available resources.

Implements: blueprint cleaning-time-allowance
Change-Id: I7de05a65c2221c1eb7c5b2f65bec58d6a48b2085

blazar/config.py

@@ -72,8 +72,18 @@ api_opts = [
                 help='Deploy the v1 API.'),
 ]
 
+lease_opts = [
+    cfg.IntOpt('cleaning_time',
+               default=0,
+               min=0,
+               help='The minimum interval [minutes] between the end of a '
+                    'lease and the start of the next lease for the same '
+                    'resource. This interval is used for cleanup.')
+]
+
 CONF = cfg.CONF
 CONF.register_cli_opts(cli_opts)
 CONF.register_opts(os_opts)
 CONF.register_opts(api_opts)
+CONF.register_opts(lease_opts)
 logging.register_options(cfg.CONF)

blazar/plugins/instances/instance_plugin.py

@@ -133,9 +133,11 @@ class VirtualInstancePlugin(base.BasePlugin, nova.NovaClientWrapper):
             filters += plugins_utils.convert_requirements(resource_properties)
 
         hosts = db_api.reservable_host_get_all_by_queries(filters)
-        free_hosts, reserved_hosts = \
-            self.filter_hosts_by_reservation(hosts, start_date, end_date,
-                                             excludes_res)
+        free_hosts, reserved_hosts = self.filter_hosts_by_reservation(
+            hosts,
+            start_date - datetime.timedelta(minutes=CONF.cleaning_time),
+            end_date + datetime.timedelta(minutes=CONF.cleaning_time),
+            excludes_res)
 
         available_hosts = []
         for host_info in reserved_hosts:

blazar/plugins/oshosts/host_plugin.py

@@ -495,6 +495,11 @@ class PhysicalHostPlugin(base.BasePlugin, nova.NovaClientWrapper):
         allocated_host_ids = []
         not_allocated_host_ids = []
         filter_array = []
+        start_date_with_margin = start_date - datetime.timedelta(
+            minutes=CONF.cleaning_time)
+        end_date_with_margin = end_date + datetime.timedelta(
+            minutes=CONF.cleaning_time)
+
         # TODO(frossigneux) support "or" operator
         if hypervisor_properties:
             filter_array = plugins_utils.convert_requirements(
@@ -508,11 +513,11 @@ class PhysicalHostPlugin(base.BasePlugin, nova.NovaClientWrapper):
                 not_allocated_host_ids.append(host['id'])
             elif db_utils.get_free_periods(
                 host['id'],
-                start_date,
-                end_date,
-                end_date - start_date,
+                start_date_with_margin,
+                end_date_with_margin,
+                end_date_with_margin - start_date_with_margin
             ) == [
-                (start_date, end_date),
+                (start_date_with_margin, end_date_with_margin),
             ]:
                 allocated_host_ids.append(host['id'])
         if len(not_allocated_host_ids) >= int(min_host):

blazar/tests/plugins/instances/test_instance_plugin.py

@@ -219,8 +219,8 @@ class TestVirtualInstancePlugin(tests.TestCase):
             'disk_gb': 20,
             'amount': 2,
             'resource_properties': '',
-            'start_date': '2030-01-01 08:00',
-            'end_date': '2030-01-01 12:00'
+            'start_date': datetime.datetime(2030, 1, 1, 8, 00),
+            'end_date': datetime.datetime(2030, 1, 1, 12, 00)
             }
         expected = {'added': set(['host-2', 'host-3']), 'removed': set([])}
         ret = plugin.pickup_hosts('reservation-id1', values)
@@ -261,8 +261,8 @@ class TestVirtualInstancePlugin(tests.TestCase):
             'disk_gb': 20,
             'amount': 2,
             'resource_properties': '',
-            'start_date': '2030-01-01 08:00',
-            'end_date': '2030-01-01 12:00'
+            'start_date': datetime.datetime(2030, 1, 1, 8, 00),
+            'end_date': datetime.datetime(2030, 1, 1, 12, 00),
             }
         expected = {'added': set(['host-1', 'host-2']), 'removed': set([])}
         ret = plugin.pickup_hosts('reservation-id1', values)
@@ -315,8 +315,8 @@ class TestVirtualInstancePlugin(tests.TestCase):
             'disk_gb': 20,
             'amount': 2,
             'resource_properties': '',
-            'start_date': '2030-01-01 08:00',
-            'end_date': '2030-01-01 12:00'
+            'start_date': datetime.datetime(2030, 1, 1, 8, 00),
+            'end_date': datetime.datetime(2030, 1, 1, 12, 00)
             }
 
         expected = {'added': set(['host-1', 'host-3']), 'removed': set([])}
@@ -369,8 +369,8 @@ class TestVirtualInstancePlugin(tests.TestCase):
             'disk_gb': 20,
             'amount': 2,
             'resource_properties': '',
-            'start_date': '2030-01-01 08:00',
-            'end_date': '2030-01-01 12:00'
+            'start_date': datetime.datetime(2030, 1, 1, 8, 00),
+            'end_date': datetime.datetime(2030, 1, 1, 12, 00)
             }
 
         hosts = plugin.pickup_hosts('reservation-id1', values)

blazar/tests/plugins/test_physical_host_plugin.py

@@ -1796,6 +1796,38 @@ class PhysicalHostPluginTestCase(tests.TestCase):
             datetime.datetime(2013, 12, 19, 21, 00))
         self.assertEqual(['host1', 'host2', 'host3'], result)
 
+    def test_matching_hosts_allocated_hosts_with_cleaning_time(self):
+        def host_allocation_get_all_by_values(**kwargs):
+            if kwargs['compute_host_id'] == 'host1':
+                return True
+        self.cfg.CONF.set_override('cleaning_time', '5')
+        host_get = self.patch(
+            self.db_api,
+            'reservable_host_get_all_by_queries')
+        host_get.return_value = [
+            {'id': 'host1'},
+            {'id': 'host2'},
+            {'id': 'host3'},
+        ]
+        host_get = self.patch(
+            self.db_api,
+            'host_allocation_get_all_by_values')
+        host_get.side_effect = host_allocation_get_all_by_values
+        host_get = self.patch(
+            self.db_utils,
+            'get_free_periods')
+        host_get.return_value = [
+            (datetime.datetime(2013, 12, 19, 20, 00)
+             - datetime.timedelta(minutes=5),
+             datetime.datetime(2013, 12, 19, 21, 00)
+             + datetime.timedelta(minutes=5))
+        ]
+        result = self.fake_phys_plugin._matching_hosts(
+            '[]', '[]', '3-3',
+            datetime.datetime(2013, 12, 19, 20, 00),
+            datetime.datetime(2013, 12, 19, 21, 00))
+        self.assertEqual(['host1', 'host2', 'host3'], result)
+
     def test_matching_hosts_not_matching(self):
         host_get = self.patch(
             self.db_api,

releasenotes/notes/cleaning-time-825d148b704b0c56.yaml

@@ -0,0 +1,12 @@
+---
+features:
+  - |
+    A time margin for cleaning up resources between the end of a lease and the
+    start of the next lease is introduced. Leases are allocated to resources
+    only if they have enough spare time for cleaning up before and after the
+    lease. Note that this cleaning time is not included in the lease time, but
+    is taken into account when looking for available resources. The length of
+    cleaning time can be configured by the configuration option
+    **cleaning_time** in the [DEFAULT] section. The default value for this
+    option is **0**, in which case the behavior is the same as previous
+    releases.