xain_fl.fl.coordinator package

Contains coordinator logic which runs the central server in federated learning. It consists of the following modules:

  • aggregate

  • controller

Submodules

xain_fl.fl.coordinator.aggregate module

Provides an abstract base class Aggregator and multiple sub-classes

class xain_fl.fl.coordinator.aggregate.Aggregator

Bases: abc.ABC

Abstract base class for model weights aggregation strategies.

abstract aggregate(multiple_model_weights, aggregation_data)

Aggregate the weights of multiple models.

Parameters

  • multiple_model_weights (List[ndarray]) – The weights of multiple models.

  • aggregation_data (List[int]) – Meta data for model aggregation.

Returns

The aggregated model weights.

Return type

ndarray

class xain_fl.fl.coordinator.aggregate.IdentityAggregator

Bases: xain_fl.fl.coordinator.aggregate.Aggregator

Identity aggregation.

aggregate(multiple_model_weights, aggregation_data)

Identity aggregation only for one set of model weights.

Parameters

  • multiple_model_weights (List[ndarray]) – The weights of multiple models. Must have only one set of weights.

  • aggregation_data (List[int]) – Meta data for model aggregation. Not used here.

Returns

The identical model weights.

Return type

ndarray

Raises

ValueError – If more than one set of model weights is provided.

class xain_fl.fl.coordinator.aggregate.ModelSumAggregator

Bases: xain_fl.fl.coordinator.aggregate.Aggregator

Summation of models aggregation.

aggregate(multiple_model_weights, aggregation_data)

Aggregate the weights of multiple models by summation.

Parameters

  • multiple_model_weights (List[ndarray]) – The weights of multiple models.

  • aggregation_data (List[int]) – Meta data for model aggregation. Not used here.

Returns

The aggregated model weights.

Return type

ndarray

class xain_fl.fl.coordinator.aggregate.WeightedAverageAggregator

Bases: xain_fl.fl.coordinator.aggregate.Aggregator

Weighted average aggregation.

aggregate(multiple_model_weights, aggregation_data)

Aggregate the weights of multiple models by weighted averages.

Proposed by McMahan et al in: https://arxiv.org/abs/1602.05629

Parameters

  • multiple_model_weights (List[ndarray]) – The weights of multiple models.

  • aggregation_data (List[int]) – Meta data for model aggregation. Here it is expected to be the number of train samples per set of model weights. If all numbers are zero, e.g. in a 0th round for weight initialization, then all model weights are weighted equally.

Returns

The aggregated model weights.

Return type

ndarray

xain_fl.fl.coordinator.controller module

Provides an abstract base class Controller and the RandomController currently used by the Coordinator.

class xain_fl.fl.coordinator.controller.Controller(fraction_of_participants=1.0)

Bases: abc.ABC

Abstract base class which provides an interface to the coordinator that enables different selection strategies.

fraction_of_participants

The fraction of total participant IDs to be selected. Defaults to 1.0, meaning that all participant IDs will be selected. It must be in the (0.0, 1.0] interval.

Type

float, optional

get_num_ids_to_select(len_participant_ids)

Calculates how many participant IDs need to be selected.

Parameters

len_participant_ids (int) – The length of the list of IDs of all the available participants.

Returns

Number of participant IDs to be selected

Return type

int

abstract select_ids(participant_ids)

Returns the selected indices of next round.

Parameters

participant_ids (list of str) – The list of IDs of all the available participants, a subset of which will be selected.

Returns

List of selected participant IDs

Return type

list of str

class xain_fl.fl.coordinator.controller.IdController(fraction_of_participants=1.0)

Bases: xain_fl.fl.coordinator.controller.Controller

[summary

… todo: Advance docstrings (https://xainag.atlassian.net/browse/XP-425)

select_ids(participant_ids)

Selects all given participants.

Parameters

participant_ids (list of str) – The list of IDs of all the available participants, a subset of which will be selected.

Returns

List of selected participant IDs

Return type

list of str

class xain_fl.fl.coordinator.controller.RandomController(fraction_of_participants=1.0)

Bases: xain_fl.fl.coordinator.controller.Controller

[summary]

Parameters

Controller ([type]) – [description]

select_ids(participant_ids)

Randomly samples self.num_ids_to_select from the population of participants_ids, without replacement.

Parameters

participant_ids (list of str) – The list of IDs of all the available participants, a subset of which will be selected.

Returns

List of selected participant IDs

Return type

list of str