Merge lp:~allenap/maas/keep-interval-low-at-start into lp:~maas-committers/maas/trunk

[Gavin Panella]

Check frequently for new event-loops for a period after starting.

[Raphaël Badin (rvb)]

review: Approve

=== modified file 'src/provisioningserver/rpc/clusterservice.py'
--- src/provisioningserver/rpc/clusterservice.py	2014-10-01 10:19:28 +0000
+++ src/provisioningserver/rpc/clusterservice.py	2014-10-02 00:34:23 +0000
@@ -486,12 +486,16 @@
 
     :ivar connections: A mapping of eventloop names to protocol
         instances connected to it.
+    :ivar time_started: Records the time that `startService` was last called,
+        or `None` if it hasn't yet.
     """
 
     INTERVAL_LOW = 2  # seconds.
     INTERVAL_MID = 10  # seconds.
     INTERVAL_HIGH = 30  # seconds.
 
+    time_started = None
+
     def __init__(self, reactor):
         super(ClusterClientService, self).__init__(
             self._calculate_interval(None, None), self.update)
@@ -506,6 +510,10 @@
         # occur in the URL's netloc portion as part of a port specification.
         twisted.web.client._URI = PatchedURI
 
+    def startService(self):
+        self.time_started = self.clock.seconds()
+        super(ClusterClientService, self).startService()
+
     def getClient(self):
         """Returns a :class:`common.Client` connected to a region.
 
@@ -572,11 +580,21 @@
         connections, so that this can quickly obtain its first
         connection.
 
+        The interval is also `INTERVAL_LOW` for a time after the service
+        starts. This helps to get everything connected quickly when the
+        cluster is started at a similar time to the region.
+
         The interval changes to `INTERVAL_MID` seconds when there are
         some connections, but fewer than there are event-loops.
 
         After that it drops back to `INTERVAL_HIGH` seconds.
         """
+        if self.time_started is not None:
+            time_running = self.clock.seconds() - self.time_started
+            if time_running < self.INTERVAL_HIGH:
+                # This service has recently started; keep trying regularly.
+                return self.INTERVAL_LOW
+
         if num_eventloops is None:
             # The region is not available; keep trying regularly.
             return self.INTERVAL_LOW

=== modified file 'src/provisioningserver/rpc/tests/test_clusterservice.py'
--- src/provisioningserver/rpc/tests/test_clusterservice.py	2014-10-01 09:45:49 +0000
+++ src/provisioningserver/rpc/tests/test_clusterservice.py	2014-10-02 00:34:23 +0000
@@ -673,26 +673,37 @@
 
     scenarios = (
         ("initial", {
+            "time_running": 0,
             "num_eventloops": None,
             "num_connections": None,
             "expected": ClusterClientService.INTERVAL_LOW,
         }),
+        ("shortly-after-start", {
+            "time_running": 10,
+            "num_eventloops": 1,  # same as num_connections.
+            "num_connections": 1,  # same as num_eventloops.
+            "expected": ClusterClientService.INTERVAL_LOW,
+        }),
         ("no-event-loops", {
+            "time_running": 1000,
             "num_eventloops": 0,
             "num_connections": sentinel.undefined,
             "expected": ClusterClientService.INTERVAL_LOW,
         }),
         ("no-connections", {
+            "time_running": 1000,
             "num_eventloops": 1,  # anything > 1.
             "num_connections": 0,
             "expected": ClusterClientService.INTERVAL_LOW,
         }),
         ("fewer-connections-than-event-loops", {
+            "time_running": 1000,
             "num_eventloops": 2,  # anything > num_connections.
             "num_connections": 1,  # anything > 0.
             "expected": ClusterClientService.INTERVAL_MID,
         }),
         ("default", {
+            "time_running": 1000,
             "num_eventloops": 3,  # same as num_connections.
             "num_connections": 3,  # same as num_eventloops.
             "expected": ClusterClientService.INTERVAL_HIGH,
@@ -711,6 +722,7 @@
     def test__calculate_interval(self):
         service = self.make_inert_client_service()
         service.startService()
+        service.clock.advance(self.time_running)
         self.assertEqual(
             self.expected, service._calculate_interval(
                 self.num_eventloops, self.num_connections))