async def _first_k_active(self, node: DHTNode, uid_prefixes: List[str],
k: int, max_prefetch: int, chunk_size: int,
future: MPFuture):
num_workers_per_chunk = min(chunk_size, self.max_workers or chunk_size)
total_chunks = (len(uid_prefixes) - 1) // chunk_size + 1
found: List[Tuple[str, RemoteExpert]] = []
pending_tasks = deque(
asyncio.create_task(
node.get_many(uid_prefixes[chunk_i * chunk_size:(chunk_i + 1) *
chunk_size],
num_workers=num_workers_per_chunk))
for chunk_i in range(min(max_prefetch + 1, total_chunks))
) # pre-dispatch first task and up to max_prefetch additional tasks
for chunk_i in range(total_chunks):
# parse task results in chronological order, launch additional tasks on demand
response = await pending_tasks.popleft()
for uid_prefix in uid_prefixes[chunk_i * chunk_size:(chunk_i + 1) *
chunk_size]:
maybe_expert_data, maybe_expiration_time = response[uid_prefix]
if maybe_expiration_time is not None: # found active peer
found.append(
(uid_prefix, RemoteExpert(**maybe_expert_data)))
# if we found enough active experts, finish immediately
if len(found) >= k:
break
if len(found) >= k:
break
pre_dispatch_chunk_i = chunk_i + len(pending_tasks) + 1
if pre_dispatch_chunk_i < total_chunks:
pending_tasks.append(
asyncio.create_task(
node.get_many(
uid_prefixes[pre_dispatch_chunk_i *
chunk_size:(pre_dispatch_chunk_i +
1) * chunk_size],
num_workers=num_workers_per_chunk)))
for task in pending_tasks:
task.cancel()
# return k active prefixes or as many as we could find
future.set_result(OrderedDict(found))
def run_node(node_id, peers, status_pipe: mp.Pipe):
if asyncio.get_event_loop().is_running():
asyncio.get_event_loop().stop() # if we're in jupyter, get rid of its built-in event loop
asyncio.set_event_loop(asyncio.new_event_loop())
loop = asyncio.get_event_loop()
node = loop.run_until_complete(DHTNode.create(node_id, initial_peers=peers))
status_pipe.send(node.port)
while True:
loop.run_forever()
async def _get_active_successors(self, node: DHTNode, prefixes: List[ExpertPrefix], grid_size: Optional[int] = None,
num_workers: Optional[int] = None, future: Optional[MPFuture] = None
) -> Dict[ExpertPrefix, Dict[Coordinate, UidEndpoint]]:
grid_size = grid_size or float('inf')
num_workers = num_workers or min(len(prefixes), self.max_workers or len(prefixes))
dht_responses = await node.get_many(keys=prefixes, num_workers=num_workers)
successors: Dict[ExpertPrefix, Dict[Coordinate, UidEndpoint]] = {}
for prefix, found in dht_responses.items():
if found and isinstance(found.value, dict):
successors[prefix] = {coord: UidEndpoint(*match.value) for coord, match in found.value.items()
if isinstance(coord, Coordinate) and 0 <= coord < grid_size
and isinstance(getattr(match, 'value', None), list) and len(match.value) == 2}
else:
successors[prefix] = {}
if found is None and self.negative_caching:
logger.debug(f"DHT negative caching: storing a 'no prefix' entry for {prefix}")
asyncio.create_task(node.store(prefix, subkey=-1, value=None,
expiration_time=get_dht_time() + self.expiration))
if future:
future.set_result(successors)
return successors
def test_dht_node():
# create dht with 50 nodes + your 51-st node
dht: Dict[Endpoint, DHTID] = {}
processes: List[mp.Process] = []
for i in range(50):
node_id = DHTID.generate()
peers = random.sample(dht.keys(), min(len(dht), 5))
pipe_recv, pipe_send = mp.Pipe(duplex=False)
proc = mp.Process(target=run_node,
args=(node_id, peers, pipe_send),
daemon=True)
proc.start()
port = pipe_recv.recv()
processes.append(proc)
dht[f"{LOCALHOST}:{port}"] = node_id
loop = asyncio.get_event_loop()
me = loop.run_until_complete(
DHTNode.create(initial_peers=random.sample(dht.keys(), 5),
parallel_rpc=10,
cache_refresh_before_expiry=False))
# test 1: find self
nearest = loop.run_until_complete(
me.find_nearest_nodes([me.node_id], k_nearest=1))[me.node_id]
assert len(nearest) == 1 and ':'.join(
nearest[me.node_id].split(':')[-2:]) == f"{LOCALHOST}:{me.port}"
# test 2: find others
for i in range(10):
ref_endpoint, query_id = random.choice(list(dht.items()))
nearest = loop.run_until_complete(
me.find_nearest_nodes([query_id], k_nearest=1))[query_id]
assert len(nearest) == 1
found_node_id, found_endpoint = next(iter(nearest.items()))
assert found_node_id == query_id and ':'.join(
found_endpoint.split(':')[-2:]) == ref_endpoint
# test 3: find neighbors to random nodes
accuracy_numerator = accuracy_denominator = 0 # top-1 nearest neighbor accuracy
jaccard_numerator = jaccard_denominator = 0 # jaccard similarity aka intersection over union
all_node_ids = list(dht.values())
for i in range(10):
query_id = DHTID.generate()
k_nearest = random.randint(1, 10)
exclude_self = random.random() > 0.5
nearest = loop.run_until_complete(
me.find_nearest_nodes([query_id],
k_nearest=k_nearest,
exclude_self=exclude_self))[query_id]
nearest_nodes = list(nearest) # keys from ordered dict
assert len(
nearest_nodes
) == k_nearest, "beam search must return exactly k_nearest results"
assert me.node_id not in nearest_nodes or not exclude_self, "if exclude, results shouldn't contain self"
assert np.all(np.diff(query_id.xor_distance(nearest_nodes)) >= 0
), "results must be sorted by distance"
ref_nearest = heapq.nsmallest(k_nearest + 1,
all_node_ids,
key=query_id.xor_distance)
if exclude_self and me.node_id in ref_nearest:
ref_nearest.remove(me.node_id)
if len(ref_nearest) > k_nearest:
ref_nearest.pop()
accuracy_numerator += nearest_nodes[0] == ref_nearest[0]
accuracy_denominator += 1
jaccard_numerator += len(
set.intersection(set(nearest_nodes), set(ref_nearest)))
jaccard_denominator += k_nearest
accuracy = accuracy_numerator / accuracy_denominator
print("Top-1 accuracy:", accuracy) # should be 98-100%
jaccard_index = jaccard_numerator / jaccard_denominator
print("Jaccard index (intersection over union):",
jaccard_index) # should be 95-100%
assert accuracy >= 0.9, f"Top-1 accuracy only {accuracy} ({accuracy_numerator} / {accuracy_denominator})"
assert jaccard_index >= 0.9, f"Jaccard index only {accuracy} ({accuracy_numerator} / {accuracy_denominator})"
# test 4: find all nodes
dummy = DHTID.generate()
nearest = loop.run_until_complete(
me.find_nearest_nodes([dummy], k_nearest=len(dht) + 100))[dummy]
assert len(nearest) == len(dht) + 1
assert len(
set.difference(set(nearest.keys()),
set(all_node_ids) | {me.node_id})) == 0
# test 5: node without peers
detached_node = loop.run_until_complete(DHTNode.create())
nearest = loop.run_until_complete(detached_node.find_nearest_nodes(
[dummy]))[dummy]
assert len(nearest) == 1 and nearest[
detached_node.node_id] == f"{LOCALHOST}:{detached_node.port}"
nearest = loop.run_until_complete(
detached_node.find_nearest_nodes([dummy], exclude_self=True))[dummy]
assert len(nearest) == 0
# test 6 store and get value
true_time = get_dht_time() + 1200
assert loop.run_until_complete(me.store("mykey", ["Value", 10], true_time))
that_guy = loop.run_until_complete(
DHTNode.create(initial_peers=random.sample(dht.keys(), 3),
parallel_rpc=10,
cache_refresh_before_expiry=False,
cache_locally=False))
for node in [me, that_guy]:
val, expiration_time = loop.run_until_complete(node.get("mykey"))
assert val == ["Value", 10], "Wrong value"
assert expiration_time == true_time, f"Wrong time"
assert loop.run_until_complete(detached_node.get("mykey")) is None
# test 7: bulk store and bulk get
keys = 'foo', 'bar', 'baz', 'zzz'
values = 3, 2, 'batman', [1, 2, 3]
store_ok = loop.run_until_complete(
me.store_many(keys, values, expiration_time=get_dht_time() + 999))
assert all(store_ok.values()), "failed to store one or more keys"
response = loop.run_until_complete(me.get_many(keys[::-1]))
for key, value in zip(keys, values):
assert key in response and response[key][0] == value
# test 8: store dictionaries as values (with sub-keys)
upper_key, subkey1, subkey2, subkey3 = 'ololo', 'k1', 'k2', 'k3'
now = get_dht_time()
assert loop.run_until_complete(
me.store(upper_key,
subkey=subkey1,
value=123,
expiration_time=now + 10))
assert loop.run_until_complete(
me.store(upper_key,
subkey=subkey2,
value=456,
expiration_time=now + 20))
for node in [that_guy, me]:
value, time = loop.run_until_complete(node.get(upper_key))
assert isinstance(value, dict) and time == now + 20
assert value[subkey1] == (123, now + 10)
assert value[subkey2] == (456, now + 20)
assert len(value) == 2
assert not loop.run_until_complete(
me.store(
upper_key, subkey=subkey2, value=345, expiration_time=now + 10))
assert loop.run_until_complete(
me.store(upper_key,
subkey=subkey2,
value=567,
expiration_time=now + 30))
assert loop.run_until_complete(
me.store(upper_key,
subkey=subkey3,
value=890,
expiration_time=now + 50))
loop.run_until_complete(asyncio.sleep(0.1)) # wait for cache to refresh
for node in [that_guy, me]:
value, time = loop.run_until_complete(node.get(upper_key))
assert isinstance(value, dict) and time == now + 50, (value, time)
assert value[subkey1] == (123, now + 10)
assert value[subkey2] == (567, now + 30)
assert value[subkey3] == (890, now + 50)
assert len(value) == 3
for proc in processes:
proc.terminate()
def _tester():
# note: we run everything in a separate process to re-initialize all global states from scratch
# this helps us avoid undesirable side-effects when running multiple tests in sequence
loop = asyncio.get_event_loop()
me = loop.run_until_complete(
DHTNode.create(initial_peers=random.sample(dht.keys(), 5),
parallel_rpc=10))
# test 1: find self
nearest = loop.run_until_complete(
me.find_nearest_nodes([me.node_id], k_nearest=1))[me.node_id]
assert len(nearest) == 1 and ':'.join(
nearest[me.node_id].split(':')[-2:]) == f"{LOCALHOST}:{me.port}"
# test 2: find others
for i in range(10):
ref_endpoint, query_id = random.choice(list(dht.items()))
nearest = loop.run_until_complete(
me.find_nearest_nodes([query_id], k_nearest=1))[query_id]
assert len(nearest) == 1
found_node_id, found_endpoint = next(iter(nearest.items()))
assert found_node_id == query_id and ':'.join(
found_endpoint.split(':')[-2:]) == ref_endpoint
# test 3: find neighbors to random nodes
accuracy_numerator = accuracy_denominator = 0 # top-1 nearest neighbor accuracy
jaccard_numerator = jaccard_denominator = 0 # jaccard similarity aka intersection over union
all_node_ids = list(dht.values())
for i in range(100):
query_id = DHTID.generate()
k_nearest = random.randint(1, 20)
exclude_self = random.random() > 0.5
nearest = loop.run_until_complete(
me.find_nearest_nodes([query_id],
k_nearest=k_nearest,
exclude_self=exclude_self))[query_id]
nearest_nodes = list(nearest) # keys from ordered dict
assert len(
nearest_nodes
) == k_nearest, "beam search must return exactly k_nearest results"
assert me.node_id not in nearest_nodes or not exclude_self, "if exclude, results shouldn't contain self"
assert np.all(np.diff(query_id.xor_distance(nearest_nodes)) >= 0
), "results must be sorted by distance"
ref_nearest = heapq.nsmallest(k_nearest + 1,
all_node_ids,
key=query_id.xor_distance)
if exclude_self and me.node_id in ref_nearest:
ref_nearest.remove(me.node_id)
if len(ref_nearest) > k_nearest:
ref_nearest.pop()
accuracy_numerator += nearest_nodes[0] == ref_nearest[0]
accuracy_denominator += 1
jaccard_numerator += len(
set.intersection(set(nearest_nodes), set(ref_nearest)))
jaccard_denominator += k_nearest
accuracy = accuracy_numerator / accuracy_denominator
print("Top-1 accuracy:", accuracy) # should be 98-100%
jaccard_index = jaccard_numerator / jaccard_denominator
print("Jaccard index (intersection over union):",
jaccard_index) # should be 95-100%
assert accuracy >= 0.9, f"Top-1 accuracy only {accuracy} ({accuracy_numerator} / {accuracy_denominator})"
assert jaccard_index >= 0.9, f"Jaccard index only {accuracy} ({accuracy_numerator} / {accuracy_denominator})"
# test 4: find all nodes
dummy = DHTID.generate()
nearest = loop.run_until_complete(
me.find_nearest_nodes([dummy], k_nearest=len(dht) + 100))[dummy]
assert len(nearest) == len(dht) + 1
assert len(
set.difference(set(nearest.keys()),
set(all_node_ids) | {me.node_id})) == 0
# test 5: node without peers
other_node = loop.run_until_complete(DHTNode.create())
nearest = loop.run_until_complete(
other_node.find_nearest_nodes([dummy]))[dummy]
assert len(nearest) == 1 and nearest[
other_node.node_id] == f"{LOCALHOST}:{other_node.port}"
nearest = loop.run_until_complete(
other_node.find_nearest_nodes([dummy], exclude_self=True))[dummy]
assert len(nearest) == 0
# test 6 store and get value
true_time = get_dht_time() + 1200
assert loop.run_until_complete(
me.store("mykey", ["Value", 10], true_time))
for node in [me, other_node]:
val, expiration_time = loop.run_until_complete(me.get("mykey"))
assert expiration_time == true_time, "Wrong time"
assert val == ["Value", 10], "Wrong value"
# test 7: bulk store and bulk get
keys = 'foo', 'bar', 'baz', 'zzz'
values = 3, 2, 'batman', [1, 2, 3]
store_ok = loop.run_until_complete(
me.store_many(keys, values, expiration_time=get_dht_time() + 999))
assert all(store_ok.values()), "failed to store one or more keys"
response = loop.run_until_complete(me.get_many(keys[::-1]))
for key, value in zip(keys, values):
assert key in response and response[key][0] == value
test_success.set()
