def test_handle_RequestVoteMessage_vote_for_candidate():
controller = mock.MagicMock()
id_ = 1
m = Machine(id_, controller)
m._controller.enqueue.reset_mock()
m.current_term = 2
m.log = [log.LogEntry(2, '')]
m.voted_for = None
msg = messages.RequestVoteMessage(
src=4,
dst=id_,
term=2,
candidate_id=4,
last_log_index=0,
last_log_term=2,
)
m.handle_RequestVoteMessage(msg)
enqueue_calls = m._controller.enqueue.mock_calls
call = enqueue_calls[0]
name, args, kwargs = call
first_arg = args[0]
assert isinstance(first_arg, messages.RequestVoteResponseMessage)
assert first_arg.src == id_
assert first_arg.dst == 4
assert first_arg.term == m.current_term
assert first_arg.vote_granted
def test_handle_no_comm_election_timeout_leader_to_leader(now):
now.return_value = 123456789
controller = mock.MagicMock()
id_ = 1
m = Machine(id_, controller)
m._controller.enqueue.reset_mock()
m.current_term = 5
m._state = constants.State.LEADER
m.voted_for = id_
m.last_applied = 17
msg = messages.ElectionTimeoutMessage(
src=2,
dst=id_,
term=m.current_term,
time=utils.now()
)
m.handle_ElectionTimeoutMesssage(msg)
assert m.current_term == 5
assert m._state == constants.State.LEADER
assert m.voted_for == id_
enqueue_calls = m._controller.enqueue.mock_calls
call = enqueue_calls[0]
name, args, kwargs = call
first_arg = args[0]
assert isinstance(first_arg, messages.ElectionTimeoutMessage)
assert first_arg.src == id_
assert first_arg.dst == id_
assert first_arg.term == m.current_term
assert first_arg.time == 123456789 + m._election_timeout
def test_handle_append_entries_candidate_to_candidate_msg_term_too_small():
controller = mock.MagicMock()
servers = [(), ()] # Need two items in list for id = 1 to be valid
id_ = 1
m = Machine(id_, controller, servers)
m.current_term = 5
m._state = constants.State.CANDIDATE
m.voted_for = id_
msg = messages.AppendEntriesMessage(
src=2,
dst=id_,
term=3, # Old term
leader_id=2,
prev_log_index=0,
prev_log_term=0,
entries=(),
leader_commit=0,
)
m.handle_AppendEntriesMessage(msg)
assert m._state == constants.State.CANDIDATE
assert m.voted_for == id_
def test_handle_request_vote_reply_is_candidate_win_election(now):
now.return_value = 123456789
controller = mock.MagicMock()
id_ = 1
m = Machine(id_, controller)
m._controller.enqueue.reset_mock()
m.current_term = 5
m.voted_for = id_
m._state = constants.State.CANDIDATE
m._votes = 2
m.log = [log.LogEntry(m.current_term, '')]
msg = messages.RequestVoteResponseMessage(
src=0,
dst=1,
term=m.current_term,
)
m.handle_RequestVoteResponseMessage(msg)
assert m._state == constants.State.LEADER
# Assert messages sent to all other servers
enqueue_calls = m._controller.enqueue.mock_calls[:-1]
assert len(enqueue_calls) == len(m._servers) - 1
dsts = set()
for mock_call in enqueue_calls:
name, args, kwargs = mock_call
msg = args[0]
assert isinstance(msg, messages.AppendEntriesMessage)
assert msg.src == id_
dsts.add(msg.dst)
assert msg.term == m.current_term
assert msg.leader_id == id_
assert msg.prev_log_term == 5
assert msg.prev_log_index == 0
assert msg.entries == ()
assert msg.leader_commit == 0
assert set(range(len(m._servers))) - {id_} == dsts
call = m._controller.enqueue.mock_calls[-1]
name, args, kwargs = call
first_arg = args[0]
assert isinstance(first_arg, messages.LeaderTimeoutMessage)
assert first_arg.src == id_
assert first_arg.dst == id_
assert first_arg.term == m.current_term
assert first_arg.time == 123456789 + m._leader_timeout
def test_handle_request_vote_reply_is_follower():
controller = mock.MagicMock()
id_ = 1
m = Machine(id_, controller)
m._controller.enqueue.reset_mock()
m.current_term = 5
m.voted_for = id_
m._state = constants.State.FOLLOWER
msg = messages.RequestVoteResponseMessage(
src=0,
dst=1,
term=99,
)
m.handle_RequestVoteResponseMessage(msg)
assert m._state == constants.State.FOLLOWER
m._controller.enqueue.assert_not_called()
def test_handle_request_vote_reply_is_candidate_vote_not_granted():
controller = mock.MagicMock()
id_ = 1
m = Machine(id_, controller)
m._controller.enqueue.reset_mock()
m.current_term = 5
m.voted_for = id_
m._state = constants.State.CANDIDATE
m._votes = 2
msg = messages.RequestVoteResponseMessage(
src=0,
dst=1,
term=m.current_term,
vote_granted=False,
)
m.handle_RequestVoteResponseMessage(msg)
assert m._state == constants.State.CANDIDATE
m._controller.enqueue.assert_not_called()
def test_handle_no_comm_election_timeout_candidate_to_candidate():
controller = mock.MagicMock()
id_ = 1
m = Machine(id_, controller)
m.get_last_log_data = lambda: (5, 17)
m._controller.enqueue.reset_mock()
m.current_term = 5
m._state = constants.State.CANDIDATE
m.voted_for = None
m.last_applied = 17
msg = messages.ElectionTimeoutMessage(
src=2,
dst=id_,
term=m.current_term,
time=utils.now()
)
m.handle_ElectionTimeoutMesssage(msg)
assert m.current_term == 6
assert m._state == constants.State.CANDIDATE
assert m.voted_for == id_
# Assert messages sent to all other servers
enqueue_calls = m._controller.enqueue.mock_calls
assert len(enqueue_calls) == len(m._servers) - 1
dsts = set()
for mock_call in enqueue_calls:
name, args, kwargs = mock_call
msg = args[0]
assert isinstance(msg, messages.RequestVoteMessage)
assert msg.src == id_
dsts.add(msg.dst)
assert msg.term == 6
assert msg.candidate_id == id_
assert msg.last_log_index == 17
assert msg.last_log_term == 5
assert set(range(len(m._servers))) - {id_} == dsts
def test_handle_append_entries_leader_to_follower():
controller = mock.MagicMock()
servers = [(), ()] # Need two items in list for id = 1 to be valid
id_ = 1
m = Machine(id_, controller, servers)
m.current_term = 5
m._state = constants.State.LEADER
msg = messages.AppendEntriesMessage(
src=2,
dst=id_,
term=7, # More recent term
leader_id=2,
prev_log_index=0,
prev_log_term=0,
entries=(),
leader_commit=0,
)
m.handle_AppendEntriesMessage(msg)
assert m._state == constants.State.FOLLOWER
assert m.voted_for == 2
def test_handle_append_entries_candidate_with_log_truncation():
controller = mock.MagicMock()
servers = [(), ()] # Need two items in list for id = 1 to be valid
id_ = 1
m = Machine(id_, controller, servers)
m.current_term = 2
m.log = [
log.LogEntry(2, 'a'),
log.LogEntry(2, 'b'),
log.LogEntry(2, 'c'),
]
m._state = constants.State.FOLLOWER
m.voted_for = id_
msg = messages.AppendEntriesMessage(
src=2,
dst=id_,
term=2,
leader_id=2,
prev_log_index=1,
prev_log_term=2,
entries=[
log.LogEntry(2, 'd'),
log.LogEntry(2, 'e'),
],
leader_commit=4,
)
m.handle_AppendEntriesMessage(msg)
assert m.log == [
log.LogEntry(2, 'a'),
log.LogEntry(2, 'b'),
log.LogEntry(2, 'd'),
log.LogEntry(2, 'e'),
]