class HookSchedulerTest(ServiceStateManagerTestBase):
@inlineCallbacks
def setUp(self):
yield super(HookSchedulerTest, self).setUp()
self.client = self.get_zookeeper_client()
self.unit_relation = self.mocker.mock()
self.executions = []
self.service = yield self.add_service_from_charm("wordpress")
self.scheduler = HookScheduler(self.client,
self.collect_executor,
self.unit_relation,
"",
unit_name="wordpress/0")
self.log_stream = self.capture_logging("hook.scheduler",
level=logging.DEBUG)
def collect_executor(self, context, change):
self.executions.append((context, change))
# Event reduction/coalescing cases
def test_reduce_removed_added(self):
""" A remove event for a node followed by an add event,
results in a modify event.
"""
self.scheduler.notify_change(old_units=["u-1"], new_units=[])
self.scheduler.notify_change(old_units=[], new_units=["u-1"])
self.scheduler.run()
self.assertEqual(len(self.executions), 1)
self.assertEqual(self.executions[0][1].change_type, "modified")
output = ("relation change old:['u-1'], new:[], modified:()",
"relation change old:[], new:['u-1'], modified:()", "start",
"executing hook for u-1:modified\n")
self.assertEqual(self.log_stream.getvalue(), "\n".join(output))
def test_reduce_modify_remove_add(self):
"""A modify, remove, add event for a node results in a modify.
An extra validation of the previous test.
"""
self.scheduler.notify_change(modified=["u-1"])
self.scheduler.notify_change(old_units=["u-1"], new_units=[])
self.scheduler.notify_change(old_units=[], new_units=["u-1"])
self.scheduler.run()
self.assertEqual(len(self.executions), 1)
self.assertEqual(self.executions[0][1].change_type, "modified")
def test_reduce_add_modify(self):
"""An add and modify event for a node are coalesced to an add."""
self.scheduler.notify_change(old_units=[], new_units=["u-1"])
self.scheduler.notify_change(modified=["u-1"])
self.scheduler.run()
self.assertEqual(len(self.executions), 1)
self.assertEqual(self.executions[0][1].change_type, "joined")
def test_reduce_add_remove(self):
"""an add followed by a removal results in a noop."""
self.scheduler.notify_change(old_units=[], new_units=["u-1"])
self.scheduler.notify_change(old_units=["u-1"], new_units=[])
self.scheduler.run()
self.assertEqual(len(self.executions), 0)
def test_reduce_modify_remove(self):
"""Modifying and then removing a node, results in just the removal."""
self.scheduler.notify_change(old_units=["u-1"],
new_units=["u-1"],
modified=["u-1"])
self.scheduler.notify_change(old_units=["u-1"], new_units=[])
self.scheduler.run()
self.assertEqual(len(self.executions), 1)
self.assertEqual(self.executions[0][1].change_type, "departed")
def test_reduce_modify_modify(self):
"""Multiple modifies get coalesced to a single modify."""
# simulate normal startup, the first notify will always be the existing
# membership set.
self.scheduler.notify_change(old_units=[], new_units=["u-1"])
self.scheduler.run()
self.scheduler.stop()
self.assertEqual(len(self.executions), 1)
# Now continue the modify/modify reduction.
self.scheduler.notify_change(modified=["u-1"])
self.scheduler.notify_change(modified=["u-1"])
self.scheduler.notify_change(modified=["u-1"])
self.scheduler.run()
self.assertEqual(len(self.executions), 2)
self.assertEqual(self.executions[1][1].change_type, "modified")
# Other stuff.
@inlineCallbacks
def test_start_stop(self):
d = self.scheduler.run()
# starting multiple times results in an error
self.assertFailure(self.scheduler.run(), AssertionError)
self.scheduler.stop()
yield d
# stopping multiple times is not an error
yield self.scheduler.stop()
@inlineCallbacks
def test_membership_visibility_per_change(self):
"""Hooks are executed against changes, those changes are
associated to a temporal timestamp, however the changes
are scheduled for execution, and the state/time of the
world may have advanced, to present a logically consistent
view, we try to gaurantee at a minimum, that hooks will
always see the membership of a relations it was at the
time of their associated change.
"""
self.scheduler.notify_change(old_units=[], new_units=["u-1", "u-2"])
self.scheduler.notify_change(old_units=["u-1", "u-2"],
new_units=["u-2", "u-3"])
self.scheduler.notify_change(modified=["u-2"])
self.scheduler.run()
self.scheduler.stop()
# only two reduced events, u-2, u-3 add
self.assertEqual(len(self.executions), 2)
# Now the first execution (u-2 add) should only see members
# from the time of its change, not the current members. However
# since u-1 has been subsequently removed, it no longer retains
# an entry in the membership list.
change_members = yield self.executions[0][0].get_members()
self.assertEqual(change_members, ["u-2"])
self.scheduler.notify_change(modified=["u-2"])
self.scheduler.notify_change(old_units=["u-2", "u-3"],
new_units=["u-2"])
self.scheduler.run()
self.assertEqual(len(self.executions), 4)
self.assertEqual(self.executions[2][1].change_type, "modified")
# Verify modify events see the correct membership.
change_members = yield self.executions[2][0].get_members()
self.assertEqual(change_members, ["u-2", "u-3"])
@inlineCallbacks
def test_membership_visibility_with_change(self):
"""We express a stronger guarantee of the above, namely that
a hook wont see any 'active' members in a membership list, that
it hasn't previously been given a notify of before.
"""
self.scheduler.notify_change(old_units=["u-1", "u-2"],
new_units=["u-2", "u-3", "u-4"],
modified=["u-2"])
self.scheduler.run()
self.scheduler.stop()
# add for u-3, u-4, remove for u-1, modify for u-2
self.assertEqual(len(self.executions), 4)
# Verify members for each change.
self.assertEqual(self.executions[0][1].change_type, "joined")
members = yield self.executions[0][0].get_members()
self.assertEqual(members, ["u-1", "u-2", "u-3"])
self.assertEqual(self.executions[1][1].change_type, "joined")
members = yield self.executions[1][0].get_members()
self.assertEqual(members, ["u-1", "u-2", "u-3", "u-4"])
self.assertEqual(self.executions[2][1].change_type, "departed")
members = yield self.executions[2][0].get_members()
self.assertEqual(members, ["u-2", "u-3", "u-4"])
self.assertEqual(self.executions[3][1].change_type, "modified")
members = yield self.executions[2][0].get_members()
self.assertEqual(members, ["u-2", "u-3", "u-4"])
context = yield self.scheduler.get_hook_context(
RelationChange("", "", ""))
self.assertEqual((yield context.get_members()), ["u-2", "u-3", "u-4"])
@inlineCallbacks
def test_get_relation_change_empty(self):
"""Retrieving a hook context, is possible even if no
no hooks has previously been fired (Empty membership)."""
context = yield self.scheduler.get_hook_context(
RelationChange("", "", ""))
members = yield context.get_members()
self.assertEqual(members, [])
class HookSchedulerTest(ServiceStateManagerTestBase):
@inlineCallbacks
def setUp(self):
yield super(HookSchedulerTest, self).setUp()
self.client = self.get_zookeeper_client()
self.unit_relation = self.mocker.mock()
self.executions = []
self.service = yield self.add_service_from_charm("wordpress")
self.scheduler = HookScheduler(self.client,
self.collect_executor,
self.unit_relation, "",
unit_name="wordpress/0")
self.log_stream = self.capture_logging(
"hook.scheduler", level=logging.DEBUG)
def collect_executor(self, context, change):
self.executions.append((context, change))
# Event reduction/coalescing cases
def test_reduce_removed_added(self):
""" A remove event for a node followed by an add event,
results in a modify event.
"""
self.scheduler.notify_change(old_units=["u-1"], new_units=[])
self.scheduler.notify_change(old_units=[], new_units=["u-1"])
self.scheduler.run()
self.assertEqual(len(self.executions), 1)
self.assertEqual(self.executions[0][1].change_type, "modified")
output = ("relation change old:['u-1'], new:[], modified:()",
"relation change old:[], new:['u-1'], modified:()",
"start",
"executing hook for u-1:modified\n")
self.assertEqual(self.log_stream.getvalue(), "\n".join(output))
def test_reduce_modify_remove_add(self):
"""A modify, remove, add event for a node results in a modify.
An extra validation of the previous test.
"""
self.scheduler.notify_change(modified=["u-1"])
self.scheduler.notify_change(old_units=["u-1"], new_units=[])
self.scheduler.notify_change(old_units=[], new_units=["u-1"])
self.scheduler.run()
self.assertEqual(len(self.executions), 1)
self.assertEqual(self.executions[0][1].change_type, "modified")
def test_reduce_add_modify(self):
"""An add and modify event for a node are coalesced to an add."""
self.scheduler.notify_change(old_units=[], new_units=["u-1"])
self.scheduler.notify_change(modified=["u-1"])
self.scheduler.run()
self.assertEqual(len(self.executions), 1)
self.assertEqual(self.executions[0][1].change_type, "joined")
def test_reduce_add_remove(self):
"""an add followed by a removal results in a noop."""
self.scheduler.notify_change(old_units=[], new_units=["u-1"])
self.scheduler.notify_change(old_units=["u-1"], new_units=[])
self.scheduler.run()
self.assertEqual(len(self.executions), 0)
def test_reduce_modify_remove(self):
"""Modifying and then removing a node, results in just the removal."""
self.scheduler.notify_change(old_units=["u-1"],
new_units=["u-1"],
modified=["u-1"])
self.scheduler.notify_change(old_units=["u-1"], new_units=[])
self.scheduler.run()
self.assertEqual(len(self.executions), 1)
self.assertEqual(self.executions[0][1].change_type, "departed")
def test_reduce_modify_modify(self):
"""Multiple modifies get coalesced to a single modify."""
# simulate normal startup, the first notify will always be the existing
# membership set.
self.scheduler.notify_change(old_units=[], new_units=["u-1"])
self.scheduler.run()
self.scheduler.stop()
self.assertEqual(len(self.executions), 1)
# Now continue the modify/modify reduction.
self.scheduler.notify_change(modified=["u-1"])
self.scheduler.notify_change(modified=["u-1"])
self.scheduler.notify_change(modified=["u-1"])
self.scheduler.run()
self.assertEqual(len(self.executions), 2)
self.assertEqual(self.executions[1][1].change_type, "modified")
# Other stuff.
@inlineCallbacks
def test_start_stop(self):
d = self.scheduler.run()
# starting multiple times results in an error
self.assertFailure(self.scheduler.run(), AssertionError)
self.scheduler.stop()
yield d
# stopping multiple times is not an error
yield self.scheduler.stop()
@inlineCallbacks
def test_membership_visibility_per_change(self):
"""Hooks are executed against changes, those changes are
associated to a temporal timestamp, however the changes
are scheduled for execution, and the state/time of the
world may have advanced, to present a logically consistent
view, we try to gaurantee at a minimum, that hooks will
always see the membership of a relations it was at the
time of their associated change.
"""
self.scheduler.notify_change(
old_units=[], new_units=["u-1", "u-2"])
self.scheduler.notify_change(
old_units=["u-1", "u-2"], new_units=["u-2", "u-3"])
self.scheduler.notify_change(modified=["u-2"])
self.scheduler.run()
self.scheduler.stop()
# only two reduced events, u-2, u-3 add
self.assertEqual(len(self.executions), 2)
# Now the first execution (u-2 add) should only see members
# from the time of its change, not the current members. However
# since u-1 has been subsequently removed, it no longer retains
# an entry in the membership list.
change_members = yield self.executions[0][0].get_members()
self.assertEqual(change_members, ["u-2"])
self.scheduler.notify_change(modified=["u-2"])
self.scheduler.notify_change(
old_units=["u-2", "u-3"], new_units=["u-2"])
self.scheduler.run()
self.assertEqual(len(self.executions), 4)
self.assertEqual(self.executions[2][1].change_type, "modified")
# Verify modify events see the correct membership.
change_members = yield self.executions[2][0].get_members()
self.assertEqual(change_members, ["u-2", "u-3"])
@inlineCallbacks
def test_membership_visibility_with_change(self):
"""We express a stronger guarantee of the above, namely that
a hook wont see any 'active' members in a membership list, that
it hasn't previously been given a notify of before.
"""
self.scheduler.notify_change(
old_units=["u-1", "u-2"],
new_units=["u-2", "u-3", "u-4"],
modified=["u-2"])
self.scheduler.run()
self.scheduler.stop()
# add for u-3, u-4, remove for u-1, modify for u-2
self.assertEqual(len(self.executions), 4)
# Verify members for each change.
self.assertEqual(self.executions[0][1].change_type, "joined")
members = yield self.executions[0][0].get_members()
self.assertEqual(members, ["u-1", "u-2", "u-3"])
self.assertEqual(self.executions[1][1].change_type, "joined")
members = yield self.executions[1][0].get_members()
self.assertEqual(members, ["u-1", "u-2", "u-3", "u-4"])
self.assertEqual(self.executions[2][1].change_type, "departed")
members = yield self.executions[2][0].get_members()
self.assertEqual(members, ["u-2", "u-3", "u-4"])
self.assertEqual(self.executions[3][1].change_type, "modified")
members = yield self.executions[2][0].get_members()
self.assertEqual(members, ["u-2", "u-3", "u-4"])
context = yield self.scheduler.get_hook_context(
RelationChange("", "", ""))
self.assertEqual((yield context.get_members()),
["u-2", "u-3", "u-4"])
@inlineCallbacks
def test_get_relation_change_empty(self):
"""Retrieving a hook context, is possible even if no
no hooks has previously been fired (Empty membership)."""
context = yield self.scheduler.get_hook_context(
RelationChange("", "", ""))
members = yield context.get_members()
self.assertEqual(members, [])
