def on_configure_evaluate(
self, rnd: int, weights: Weights, client_manager: ClientManager
) -> List[Tuple[ClientProxy, EvaluateIns]]:
"""Configure the next round of evaluation."""
# Do not configure federated evaluation if a centralized evaluation
# function is provided
if self.eval_fn is not None:
return []
# Parameters and config
parameters = weights_to_parameters(weights)
config = {}
if self.on_evaluate_config_fn is not None:
# Custom evaluation config function provided
config = self.on_evaluate_config_fn(rnd)
evaluate_ins = EvaluateIns(parameters, config)
# Sample clients
if rnd >= 0:
sample_size, min_num_clients = self.num_evaluation_clients(
client_manager.num_available())
clients = client_manager.sample(num_clients=sample_size,
min_num_clients=min_num_clients)
else:
clients = list(client_manager.all().values())
# Return client/config pairs
return [(client, evaluate_ins) for client in clients]
def _contribution_based_sampling(
self, sample_size: int,
client_manager: ClientManager) -> List[ClientProxy]:
"""Sample clients depending on their past contributions."""
# Get all clients and gather their contributions
all_clients: Dict[str, ClientProxy] = client_manager.all()
cid_idx: Dict[int, str] = {}
raw: List[float] = []
for idx, (cid, _) in enumerate(all_clients.items()):
cid_idx[idx] = cid
penalty = 0.0
if cid in self.contributions.keys():
contribs: List[Tuple[int, int, int]] = self.contributions[cid]
penalty = statistics.mean([c / m for _, c, m in contribs])
# `p` should be:
# - High for clients which have never been picked before
# - Medium for clients which have contributed,
# but not used their entire budget
# - Low (but not 0) for clients which have been picked and used their budget
raw.append(1.1 - penalty)
# Sample clients
return normalize_and_sample(
all_clients=all_clients,
cid_idx=cid_idx,
raw=np.array(raw),
sample_size=sample_size,
use_softmax=False,
)
def _fs_based_sampling(self, sample_size: int,
client_manager: ClientManager,
fast_round: bool) -> List[ClientProxy]:
"""Sample clients with 1/k * c/m in fast rounds and 1 - c/m in slow rounds."""
all_clients: Dict[str, ClientProxy] = client_manager.all()
k = len(all_clients)
cid_idx: Dict[int, str] = {}
raw: List[float] = []
for idx, (cid, _) in enumerate(all_clients.items()):
cid_idx[idx] = cid
if cid in self.contributions.keys():
# Previously selected clients
contribs: List[Tuple[int, int, int]] = self.contributions[cid]
# pylint: disable=invalid-name
if self.use_past_contributions:
cs = [c for _, c, _ in contribs]
ms = [m for _, _, m in contribs]
c_over_m = sum(cs) / sum(ms)
else:
_, c, m = contribs[-1]
c_over_m = c / m
# pylint: enable-msg=invalid-name
if fast_round:
importance = (1 / k) * c_over_m + E
else:
importance = 1 - c_over_m + E
else:
# Previously unselected clients
if fast_round:
importance = 1 / k
else:
importance = 1
raw.append(importance)
log(
DEBUG,
"FedFS _fs_based_sampling, sample %s clients, raw %s",
str(sample_size),
str(raw),
)
return normalize_and_sample(
all_clients=all_clients,
cid_idx=cid_idx,
raw=np.array(raw),
sample_size=sample_size,
use_softmax=False,
)