def test_latency_threshold_application(self):
selector = SelectionStoreSelector()
scenario_def = {
'topology_description': {
'type':
'ReplicaSetWithPrimary',
'servers': [
{
'address': 'b:27017',
'avg_rtt_ms': 10000,
'type': 'RSSecondary',
'tag': {}
},
{
'address': 'c:27017',
'avg_rtt_ms': 20000,
'type': 'RSSecondary',
'tag': {}
},
{
'address': 'a:27017',
'avg_rtt_ms': 30000,
'type': 'RSPrimary',
'tag': {}
},
]
}
}
# Create & populate Topology such that all but one server is too slow.
rtt_times = [
srv['avg_rtt_ms']
for srv in scenario_def['topology_description']['servers']
]
min_rtt_idx = rtt_times.index(min(rtt_times))
seeds, hosts = get_addresses(
scenario_def["topology_description"]["servers"])
settings = get_topology_settings_dict(heartbeat_frequency=1,
local_threshold_ms=1,
seeds=seeds,
server_selector=selector)
topology = Topology(TopologySettings(**settings))
topology.open()
for server in scenario_def['topology_description']['servers']:
server_description = make_server_description(server, hosts)
topology.on_change(server_description)
# Invoke server selection and assert no filtering based on latency
# prior to custom server selection logic kicking in.
server = topology.select_server(ReadPreference.NEAREST)
self.assertEqual(len(selector.selection),
len(topology.description.server_descriptions()))
# Ensure proper filtering based on latency after custom selection.
self.assertEqual(server.description.address, seeds[min_rtt_idx])
def test_server_selector_bypassed(self):
selector = FunctionCallCounter(lambda x: x)
scenario_def = {
'topology_description': {
'type':
'ReplicaSetNoPrimary',
'servers': [
{
'address': 'b:27017',
'avg_rtt_ms': 10000,
'type': 'RSSecondary',
'tag': {}
},
{
'address': 'c:27017',
'avg_rtt_ms': 20000,
'type': 'RSSecondary',
'tag': {}
},
{
'address': 'a:27017',
'avg_rtt_ms': 30000,
'type': 'RSSecondary',
'tag': {}
},
]
}
}
# Create & populate Topology such that no server is writeable.
seeds, hosts = get_addresses(
scenario_def["topology_description"]["servers"])
settings = get_topology_settings_dict(heartbeat_frequency=1,
local_threshold_ms=1,
seeds=seeds,
server_selector=selector)
topology = Topology(TopologySettings(**settings))
topology.open()
for server in scenario_def['topology_description']['servers']:
server_description = make_server_description(server, hosts)
topology.on_change(server_description)
# Invoke server selection and assert no calls to our custom selector.
with self.assertRaisesRegex(ServerSelectionTimeoutError,
'No primary available for writes'):
topology.select_server(writable_server_selector,
server_selection_timeout=0.1)
self.assertEqual(selector.call_count, 0)
def test_latency_threshold_application(self):
selector = SelectionStoreSelector()
scenario_def = {
'topology_description': {
'type': 'ReplicaSetWithPrimary', 'servers': [
{'address': 'b:27017',
'avg_rtt_ms': 10000,
'type': 'RSSecondary',
'tag': {}},
{'address': 'c:27017',
'avg_rtt_ms': 20000,
'type': 'RSSecondary',
'tag': {}},
{'address': 'a:27017',
'avg_rtt_ms': 30000,
'type': 'RSPrimary',
'tag': {}},
]}}
# Create & populate Topology such that all but one server is too slow.
rtt_times = [srv['avg_rtt_ms'] for srv in
scenario_def['topology_description']['servers']]
min_rtt_idx = rtt_times.index(min(rtt_times))
seeds, hosts = get_addresses(
scenario_def["topology_description"]["servers"])
settings = get_topology_settings_dict(
heartbeat_frequency=1, local_threshold_ms=1, seeds=seeds,
server_selector=selector)
topology = Topology(TopologySettings(**settings))
topology.open()
for server in scenario_def['topology_description']['servers']:
server_description = make_server_description(server, hosts)
topology.on_change(server_description)
# Invoke server selection and assert no filtering based on latency
# prior to custom server selection logic kicking in.
server = topology.select_server(ReadPreference.NEAREST)
self.assertEqual(
len(selector.selection),
len(topology.description.server_descriptions()))
# Ensure proper filtering based on latency after custom selection.
self.assertEqual(
server.description.address, seeds[min_rtt_idx])
def test_server_selector_bypassed(self):
selector = CallCountSelector()
scenario_def = {
'topology_description': {
'type': 'ReplicaSetNoPrimary', 'servers': [
{'address': 'b:27017',
'avg_rtt_ms': 10000,
'type': 'RSSecondary',
'tag': {}},
{'address': 'c:27017',
'avg_rtt_ms': 20000,
'type': 'RSSecondary',
'tag': {}},
{'address': 'a:27017',
'avg_rtt_ms': 30000,
'type': 'RSSecondary',
'tag': {}},
]}}
# Create & populate Topology such that no server is writeable.
seeds, hosts = get_addresses(
scenario_def["topology_description"]["servers"])
settings = get_topology_settings_dict(
heartbeat_frequency=1, local_threshold_ms=1, seeds=seeds,
server_selector=selector)
topology = Topology(TopologySettings(**settings))
topology.open()
for server in scenario_def['topology_description']['servers']:
server_description = make_server_description(server, hosts)
topology.on_change(server_description)
# Invoke server selection and assert no calls to our custom selector.
with self.assertRaisesRegex(
ServerSelectionTimeoutError, 'No primary available for writes'):
topology.select_server(
writable_server_selector, server_selection_timeout=0.1)
self.assertEqual(selector.call_count, 0)