Add SWA

federatedscope/core/configs/cfg_fl_algo.py

@@ -25,6 +25,14 @@ def extend_fl_algo_cfg(cfg):
     cfg.fedprox.use = False
     cfg.fedprox.mu = 0.
 
+    # ---------------------------------------------------------------------- #
+    # fedswa related options, Stochastic Weight Averaging (SWA)
+    # ---------------------------------------------------------------------- #
+    cfg.fedswa = CN()
+    cfg.fedswa.use = False
+    cfg.fedswa.freq = 10
+    cfg.fedswa.start_rnd = 30
+
     # ---------------------------------------------------------------------- #
     # Personalization related options, pFL
     # ---------------------------------------------------------------------- #
@@ -114,5 +122,11 @@ def assert_fl_algo_cfg(cfg):
         # By default, use the same lr to normal mode
         cfg.personalization.lr = cfg.train.optimizer.lr
 
+    if cfg.fedswa.use:
+        assert cfg.fedswa.start_rnd < cfg.federate.total_round_num, \
+            f'`cfg.fedswa.start_rnd` {cfg.fedswa.start_rnd} must be smaller ' \
+            f'than `cfg.federate.total_round_num` ' \
+            f'{cfg.federate.total_round_num}.'
+
 
 register_config("fl_algo", extend_fl_algo_cfg)

federatedscope/core/configs/cfg_fl_setting.py

@@ -27,6 +27,8 @@ def extend_fl_setting_cfg(cfg):
     cfg.federate.merge_test_data = False  # For efficient simulation, users
     # can choose to merge the test data and perform global evaluation,
     # instead of perform test at each client
+    cfg.federate.merge_val_data = False  # Enabled only when
+    # `merge_test_data` is True, also for efficient simulation
 
     # the method name is used to internally determine composition of
     # different aggregators, messages, handlers, etc.,

federatedscope/core/data/base_data.py

@@ -67,10 +67,13 @@ def preprocess(self, datadict):
             datadict: dict with `client_id` as key,  `ClientData` as value.
         """
         if self.global_cfg.federate.merge_test_data:
+            merge_split = ['test']
+            if self.global_cfg.federate.merge_val_data:
+                merge_split += ['val']
             server_data = merge_data(
                 all_data=datadict,
                 merged_max_data_id=self.global_cfg.federate.client_num,
-                specified_dataset_name=['test'])
+                specified_dataset_name=merge_split)
             # `0` indicate Server
             datadict[0] = ClientData(self.global_cfg, **server_data)
 

federatedscope/core/fed_runner.py

@@ -166,6 +166,9 @@ def _setup_server(self, resource_info=None, client_resource_info=None):
         if self.cfg.vertical.use:
             from federatedscope.vertical_fl.utils import wrap_vertical_server
             server = wrap_vertical_server(server, self.cfg)
+        if self.cfg.fedswa.use:
+            from federatedscope.core.workers.wrapper import wrap_swa_server
+            server = wrap_swa_server(server)
         logger.info('Server has been set up ... ')
         return self.feat_engr_wrapper_server(server)
 

federatedscope/core/workers/wrapper/__init__.py

@@ -0,0 +1,3 @@
+from federatedscope.core.workers.wrapper.fedswa import wrap_swa_server
+
+__all__ = ['wrap_swa_server']

federatedscope/core/workers/wrapper/fedswa.py

@@ -0,0 +1,220 @@
+import types
+import logging
+
+from federatedscope.core.message import Message
+from federatedscope.core.auxiliaries.utils import merge_dict_of_results
+
+logger = logging.getLogger(__name__)
+
+
+def wrap_swa_server(server):
+    def check_and_move_on(self,
+                          check_eval_result=False,
+                          min_received_num=None):
+        if min_received_num is None:
+            if self._cfg.asyn.use:
+                min_received_num = self._cfg.asyn.min_received_num
+            else:
+                min_received_num = self._cfg.federate.sample_client_num
+        assert min_received_num <= self.sample_client_num
+
+        if check_eval_result and self._cfg.federate.mode.lower(
+        ) == "standalone":
+            # in evaluation stage and standalone simulation mode, we assume
+            # strong synchronization that receives responses from all clients
+            min_received_num = len(self.comm_manager.get_neighbors().keys())
+
+        move_on_flag = True  # To record whether moving to a new training
+        # round or finishing the evaluation
+        if self.check_buffer(self.state, min_received_num, check_eval_result):
+            if not check_eval_result:
+                # Receiving enough feedback in the training process
+                aggregated_num = self._perform_federated_aggregation()
+
+                self.state += 1
+
+                # FedSWA cache model
+                if self.state == self._cfg.fedswa.start_rnd:
+                    self.swa_models_ws = [
+                        model.state_dict() for model in self.models
+                    ]
+                    self.swa_rnd = 1
+                elif self.state > \
+                    self._cfg.fedswa.start_rnd and \
+                        (self.state - self._cfg.fedswa.start_rnd) % \
+                        self._cfg.fedswa.freq == 0:
+                    logger.info(f'FedSWA cache {self.swa_rnd} models.')
+                    for model, new_model in zip(self.swa_models_ws,
+                                                self.models):
+                        new_model = new_model.state_dict()
+                        for key in model.keys():
+                            model[key] = (model[key] * self.swa_rnd +
+                                          new_model[key]) / (self.swa_rnd + 1)
+                    self.swa_rnd += 1
+
+                if self.state % self._cfg.eval.freq == 0 and self.state != \
+                        self.total_round_num:
+                    #  Evaluate
+                    logger.info(f'Server: Starting evaluation at the end '
+                                f'of round {self.state - 1}.')
+                    self.eval()
+
+                if self.state < self.total_round_num:
+                    # Move to next round of training
+                    logger.info(
+                        f'----------- Starting a new training round (Round '
+                        f'#{self.state}) -------------')
+                    # Clean the msg_buffer
+                    self.msg_buffer['train'][self.state - 1].clear()
+                    self.msg_buffer['train'][self.state] = dict()
+                    self.staled_msg_buffer.clear()
+                    # Start a new training round
+                    self._start_new_training_round(aggregated_num)
+                else:
+                    # Final Evaluate
+                    logger.info('Server: Training is finished! Starting '
+                                'evaluation.')
+                    self.eval()
+
+            else:
+                # Receiving enough feedback in the evaluation process
+                self._merge_and_format_eval_results()
+
+        else:
+            move_on_flag = False
+
+        return move_on_flag
+
+    def eval(self):
+        if self._cfg.federate.make_global_eval:
+            for i in range(self.model_num):
+                trainer = self.trainers[i]
+
+                if self.eval_swa:
+                    # Use swa model
+                    fedavg_model_w = self.models[i].state_dict()
+                    self.models[i].load_state_dict(self.swa_models_ws[i])
+
+                # Preform evaluation in server
+                metrics = {}
+                for split in self._cfg.eval.split:
+                    eval_metrics = trainer.evaluate(
+                        target_data_split_name=split)
+                    metrics.update(**eval_metrics)
+
+                formatted_eval_res = self._monitor.format_eval_res(
+                    metrics,
+                    rnd=self.state,
+                    role='Server SWA#' if self.eval_swa else 'Server #',
+                    forms=self._cfg.eval.report,
+                    return_raw=self._cfg.federate.make_global_eval)
+
+                if self.eval_swa:
+                    # Restore
+                    self.models[i].load_state_dict(fedavg_model_w)
+                    self.best_results = formatted_eval_res['Results_raw']
+                else:
+                    self._monitor.update_best_result(
+                        self.best_results,
+                        formatted_eval_res['Results_raw'],
+                        results_type="server_global_eval")
+                    self.history_results = merge_dict_of_results(
+                        self.history_results, formatted_eval_res)
+                self._monitor.save_formatted_results(formatted_eval_res)
+                logger.info(formatted_eval_res)
+            self.check_and_save()
+        else:
+            if self.eval_swa:
+                for i in range(self.model_num):
+                    # Use swa model
+                    fedavg_model_w = self.models[i].state_dict()
+                    self.models[i].load_state_dict(self.swa_models_ws[i])
+            # Preform evaluation in clients
+            self.broadcast_model_para(msg_type='evaluate',
+                                      filter_unseen_clients=False)
+
+            if self.eval_swa:
+                for i in range(self.model_num):
+                    self.models[i].load_state_dict(fedavg_model_w)
+
+    def check_and_save(self):
+        """
+        To save the results and save model after each evaluation, and check \
+        whether to early stop.
+        """
+
+        # early stopping
+        if "Results_weighted_avg" in self.history_results and \
+                self._cfg.eval.best_res_update_round_wise_key in \
+                self.history_results['Results_weighted_avg']:
+            should_stop = self.early_stopper.track_and_check(
+                self.history_results['Results_weighted_avg'][
+                    self._cfg.eval.best_res_update_round_wise_key])
+        elif "Results_avg" in self.history_results and \
+                self._cfg.eval.best_res_update_round_wise_key in \
+                self.history_results['Results_avg']:
+            should_stop = self.early_stopper.track_and_check(
+                self.history_results['Results_avg'][
+                    self._cfg.eval.best_res_update_round_wise_key])
+        else:
+            should_stop = False
+
+        if should_stop:
+            self._monitor.global_converged()
+            self.comm_manager.send(
+                Message(
+                    msg_type="converged",
+                    sender=self.ID,
+                    receiver=list(self.comm_manager.neighbors.keys()),
+                    timestamp=self.cur_timestamp,
+                    state=self.state,
+                ))
+            self.state = self.total_round_num + 1
+
+        if should_stop or self.state >= self.total_round_num:
+            logger.info('Server: Final evaluation is finished! Starting '
+                        'merging results.')
+            # last round or early stopped
+            self.save_best_results()
+            if not self._cfg.federate.make_global_eval:
+                self.save_client_eval_results()
+
+            if self.eval_swa:
+                self.terminate(msg_type='finish')
+            else:
+                self.eval_swa = True
+                logger.info('Server: Evaluation with FedSWA')
+                self.eval()
+
+        # Clean the clients evaluation msg buffer
+        if not self._cfg.federate.make_global_eval:
+            round = max(self.msg_buffer['eval'].keys())
+            self.msg_buffer['eval'][round].clear()
+
+        if self.state == self.total_round_num:
+            # break out the loop for distributed mode
+            self.state += 1
+
+    def save_best_results(self):
+        """
+        To Save the best evaluation results.
+        """
+        if self._cfg.federate.save_to != '':
+            self.aggregator.save_model(self._cfg.federate.save_to, self.state)
+        formatted_best_res = self._monitor.format_eval_res(
+            results=self.best_results,
+            rnd="Final",
+            role='Server SWA#' if self.eval_swa else 'Server #',
+            forms=["raw"],
+            return_raw=True)
+        logger.info(formatted_best_res)
+        self._monitor.save_formatted_results(formatted_best_res)
+
+    # Bind method to instance
+    setattr(server, 'eval_swa', False)
+    server.check_and_move_on = types.MethodType(check_and_move_on, server)
+    server.eval = types.MethodType(eval, server)
+    server.check_and_save = types.MethodType(check_and_save, server)
+    server.save_best_results = types.MethodType(save_best_results, server)
+
+    return server

scripts/example_configs/fedswa.yaml

@@ -0,0 +1,44 @@
+use_gpu: True
+device: 0
+early_stop:
+  patience: 5
+seed: 12345
+federate:
+  mode: standalone
+  total_round_num: 100
+  sample_client_rate: 0.1
+  make_global_eval: True
+  merge_test_data: True
+  merge_val_data: True
+fedswa:
+  use: True
+  freq: 10
+  start_rnd: 75
+data:
+  root: data/
+  type: femnist
+  splits: [0.6,0.2,0.2]
+  subsample: 0.05
+  transform: [['ToTensor'], ['Normalize', {'mean': [0.9637], 'std': [0.1592]}]]
+dataloader:
+  batch_size: 10
+model:
+  type: convnet2
+  hidden: 2048
+  out_channels: 62
+train:
+  local_update_steps: 1
+  batch_or_epoch: epoch
+  optimizer:
+    lr: 0.01
+    weight_decay: 0.0
+grad:
+  grad_clip: 5.0
+criterion:
+  type: CrossEntropyLoss
+trainer:
+  type: cvtrainer
+eval:
+  freq: 10
+  metrics: ['acc', 'correct']
+  count_flops: False