High-performance Simulation with Kubernetes

This tutorial will describe how to set up high-performance simulation using a TFF runtime running on Kubernetes. The model is the same as in the previous tutorial, High-performance simulations with TFF. The only difference is that here we use a worker pool instead of a local executor.

This tutorial refers to Google Cloud's GKE to create the Kubernetes cluster, but all the steps after the cluster is created can be used with any Kubernetes installation.

Launch the TFF Workers on GKE

Note: This tutorial assumes the user has an existing GCP project.

Create a Kubernetes Cluster

The following step only needs to be done once. The cluster can be re-used for future workloads.

Follow the GKE instructions to create a container cluster. The rest of this tutorial assumes that the cluster is named tff-cluster, but the actual name isn't important. Stop following the instructions when you get to "Step 5: Deploy your application".

Deploy the TFF Worker Application

The commands to interact with GCP can be run locally or in the Google Cloud Shell. We recommend the Google Cloud Shell since it doesn't require additional setup.

1. Run the following command to launch the Kubernetes application.

$ kubectl create deployment tff-workers --image=gcr.io/tensorflow-federated/remote-executor-service:latest

1. Add a load balancer for the application.

$ kubectl expose deployment tff-workers --type=LoadBalancer --port 80 --target-port 8000

Note: This exposes your deployment to the internet and is for demo purposes only. For production use, a firewall and authentication are strongly recommended.

Look up the IP address of the loadbalancer on the Google Cloud Console. You'll need it later to connect the training loop to the worker app.

(Alternately) Launch the Docker Container Locally

$ docker run --rm -p 8000:8000 gcr.io/tensorflow-federated/remote-executor-service:latest

Set Up TFF Environment

!pip install --quiet --upgrade tensorflow-federated-nightly
!pip install --quiet --upgrade nest-asyncio

import nest_asyncio
nest_asyncio.apply()

Define the Model to Train

import collections
import time

import tensorflow as tf
import tensorflow_federated as tff

source, _ = tff.simulation.datasets.emnist.load_data()


def map_fn(example):
  return collections.OrderedDict(
      x=tf.reshape(example['pixels'], [-1, 784]), y=example['label'])


def client_data(n):
  ds = source.create_tf_dataset_for_client(source.client_ids[n])
  return ds.repeat(10).batch(20).map(map_fn)


train_data = [client_data(n) for n in range(10)]
input_spec = train_data[0].element_spec


def model_fn():
  model = tf.keras.models.Sequential([
      tf.keras.layers.InputLayer(input_shape=(784,)),
      tf.keras.layers.Dense(units=10, kernel_initializer='zeros'),
      tf.keras.layers.Softmax(),
  ])
  return tff.learning.from_keras_model(
      model,
      input_spec=input_spec,
      loss=tf.keras.losses.SparseCategoricalCrossentropy(),
      metrics=[tf.keras.metrics.SparseCategoricalAccuracy()])


trainer = tff.learning.build_federated_averaging_process(
    model_fn, client_optimizer_fn=lambda: tf.keras.optimizers.SGD(0.02))


def evaluate(num_rounds=10):
  state = trainer.initialize()
  for round in range(num_rounds):
    t1 = time.time()
    state, metrics = trainer.next(state, train_data)
    t2 = time.time()
    print('Round {}: loss {}, round time {}'.format(round, metrics.loss, t2 - t1))

Set Up the Remote Executors

By default, TFF executes all computations locally. In this step we tell TFF to connect to the Kubernetes services we set up above. Be sure to copy the IP address of your service here.

import grpc

ip_address = '0.0.0.0' 
port = 80 

channels = [grpc.insecure_channel(f'{ip_address}:{port}') for _ in range(10)]

tff.backends.native.set_remote_execution_context(channels)

Run Training

evaluate()

Round 0: loss 4.370407581329346, round time 4.201097726821899
Round 1: loss 4.1407670974731445, round time 3.3283166885375977
Round 2: loss 3.865147590637207, round time 3.098310947418213
Round 3: loss 3.534019708633423, round time 3.1565616130828857
Round 4: loss 3.272688388824463, round time 3.175067663192749
Round 5: loss 2.935391664505005, round time 3.008434534072876
Round 6: loss 2.7399251461029053, round time 3.31435227394104
Round 7: loss 2.5054931640625, round time 3.4411356449127197
Round 8: loss 2.290508985519409, round time 3.158798933029175
Round 9: loss 2.1194536685943604, round time 3.1348156929016113