On the Energy Efficiency of P2P Personalized Machine Learning using Mobile Devices

This repository contains the code to run simulations for the "On the Advantages of P2P ML on Mobile Devices" paper, submitted in ACM e-Energy 2022 conference. The repository includes the implementation of the P3 algorithm on a simulated environment, and the implementation of the P3 algorithm on Android.

Requirements

Package	Version
python	3.7
pytorch	1.9.1
torchvision	0.10.1
numpy	1.21.3

Data

We use the MNIST dataset for energy analysis and model evaluation but implementation supports also CIFAR10. Datasets will be downloaded automatically in the /data folder with the first run of the algorithm.

ML Engine

We have implemented the code to run on two ML engines. Pytorch based ML models and Numpy based models to support ML training on android devices. To configure the ML Engine, update the following line in src/conf.py ML_ENGINE = "PyTorch" # "NumPy" or "PyTorch" NB: Android implementation does not support PyTorch.

Evaluation of P3

Configuration

To build the random topology of the P2P network, we use the graph density parameter rho to estimate the number of neighbors for each nodes. In our experiments, we use the following:

• For 10 peers: rho=0.4
• For 100 peers: rho=0.8
• For 300 peers: rho=0.95

The main algorithm parameters are the following:

Argument	Description
--mp	Use message passing (MP) via sockets or shared memory (SM) (default: MP)
--rounds	Number of rounds of collaborative training (default: 500)
--num_users	Number of peers joining the P2P network (default: 100)
--epochs	Number of epochs for local training (default: 2)
--batch_size	Batch size (default: 64)
--lr	Learning rate (default: 0.1)
--momentum	SGD momentum (default: 0.9)
--model	ML model (default: mlp) Multi-Layer-Perceptron
--dataset	Dataset (default: mnist)
--iid	Data distribution, default set to IID. Set to 0 for non-IID.
--unequal	Whether to use unequal data splits for non-i.i.d setting (use 0 for equal splits)

Execution of Personalized P2P (P3)

To reproduce the experiments of model performance in the paper use the following command:

• IID data partitioning

python main.py --num_users=100 --model=mlp --dataset=mnist --iid=1 --round=500

• Balanced non-IID partitioning

python main.py --num_users=100 --model=mlp --dataset=mnist --iid=0 --unequal=0 --round=500

• Unbalanced non-IID partitioning

python main.py --num_users=100 --model=mlp --dataset=mnist --iid=0 --unequal=1 --round=500

• Network density:

Change the values of parameter $\rho$

topology = random_graph(models, rho=0.95)  # 0, 0.4, 0.7, 0.95, 0.99

Execution of Centralized Learning (CL)

python main_CL.py--model=mlp --dataset=mnist

Execution of Model Propagation (MP)

python main_MP.py --num_users=100 --model=mlp --dataset=mnist --iid=1 --round=500

Execution of FedAvg (FL)

python main_FL.py --num_users=100 --model=mlp --dataset=mnist --iid=1 --round=500

Energy Analysis

To perform energy analysis of P3 on the Linux server (Ubuntu 20.04), we developed two methods of energy readings:

• Evaluating the whole program by running the run.sh script.
• Evaluating a given method of the algorithm using python decorators.

NB: you need to disable virtualization from the bios as we shield the program to one physical core.

Requirement

We have used the following packages: powerstat, cset-shield, cpupower.

Energy consumption of the whole program

To measure the energy consumption of the whole program run the following:

./run.sh -c 0 -p avg -r 1 -d 2 -e "python main.py" -a "--num_users=100 --model=mlp"

Run ./run.sh -h to get a list of the available options and what are used for.

Energy consumption of a method

To measure the energy consumption of a given method, use the @measure_energy decorator.

For example to evaluation the energy consumption of the local learning step, add the following:

@measure_energy
def local_training(self, device='cpu', inference=True):
	log('event', 'Starting local training ...')
	...

End.