def test_overshoot(self):
"""
When overshooting the desired capacity (group was below desired,
and is now above desired), no progress was made.
"""
previous_state = GroupState(
servers=self._create_servers(4),
lb_connections=pset([])
)
current_state = GroupState(
servers=self._create_servers(6),
lb_connections=pset([])
)
desired_state = DesiredServerGroupState(
server_config=pmap(),
capacity=5,
)
self.assertRaises(
OvershootError,
measure_progress, previous_state, current_state, desired_state)
def test_capacity_closer_to_desired_when_scaling_down(self):
"""
If the capacity moves closer to the desired, progress has been
made.
"""
previous_state = GroupState(
servers=self._create_servers(4),
lb_connections=pset([])
)
current_state = GroupState(
servers=self._create_servers(2),
lb_connections=pset([])
)
desired_state = DesiredServerGroupState(
server_config=pmap(),
capacity=1,
)
progress = measure_progress(
previous_state, current_state, desired_state)
self.assertEqual(progress, 2)
def test_reaping_errored_servers(self):
"""
Errored servers are removed; no progress is made.
"""
previous_state = GroupState(
servers=(self._create_servers(1, state=ServerState.ACTIVE) |
self._create_servers(2, state=ServerState.ERROR)),
lb_connections=pset([])
)
current_state = GroupState(
servers=(self._create_servers(1, state=ServerState.ACTIVE)),
lb_connections=pset([])
)
desired_state = DesiredServerGroupState(
server_config=pmap(),
capacity=5,
)
progress = measure_progress(
previous_state, current_state, desired_state)
self.assertEqual(progress, 0)
def test_servers_going_from_build_to_error(self):
"""
When some servers go from build to error, no progress was made.
"""
previous_state = GroupState(
servers=self._create_servers(3, state=ServerState.BUILD),
lb_connections=pset([])
)
current_state = GroupState(
servers=(self._create_servers(1, state=ServerState.ACTIVE) |
self._create_servers(2, state=ServerState.ERROR)),
lb_connections=pset([])
)
desired_state = DesiredServerGroupState(
server_config=pmap(),
capacity=5,
)
progress = measure_progress(
previous_state, current_state, desired_state)
self.assertEqual(progress, 0)
def test_building_servers_towards_desired_capacity(self):
"""
When some servers are being built, which would put us closer to
the desired capacity, progress is being made.
"""
previous_state = GroupState(
servers=self._create_servers(2),
lb_connections=pset([])
)
current_state = GroupState(
servers=(self._create_servers(2, state=ServerState.ACTIVE) |
self._create_servers(2, state=ServerState.BUILD)),
lb_connections=pset([])
)
desired_state = DesiredServerGroupState(
server_config=pmap(),
capacity=5,
)
progress = measure_progress(
previous_state, current_state, desired_state)
self.assertEqual(progress, 2)
def test_servers_going_from_build_to_error_with_reaping(self):
"""
When some servers go from build to error, no progress was
made. That works correctly even if some of the errored
machines get reaped in the mean while.
"""
previous_state = GroupState(
servers=self._create_servers(3, state=ServerState.BUILD),
lb_connections=pset([])
)
current_state = GroupState(
servers=(self._create_servers(1, state=ServerState.ACTIVE) |
self._create_servers(1, state=ServerState.ERROR)),
lb_connections=pset([])
)
desired_state = DesiredServerGroupState(
server_config=pmap(),
capacity=5,
)
progress = measure_progress(
previous_state, current_state, desired_state)
self.assertEqual(progress, 0)