For illustration purposes we will use the MNIST dataset. The following code downloads the dataset and puts it in ./mnist_data.
The first 60000 images and targets are the original training set, while the last 10000 are the testing set. The training set is ordered by the labels so we shuffle them since we will use a very small portion of the data to shorten training time.
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from sklearn.datasets import fetch_mldata
from sklearn.utils import shuffle
mnist = fetch_mldata('MNIST original', data_home='./mnist_data')
X, y = shuffle(mnist.data[:60000], mnist.target[:60000])
X_small = X[:100]
y_small = y[:100]
# Note: using only 10% of the training data
X_large = X[:6000]
y_large = y[:6000]
For illustration purposes we will use the RandomForestClassifier with RandomizedSearchCV:
http://scikit-learn.org/stable/modules/generated/sklearn.ensemble.RandomForestClassifier.html
http://scikit-learn.org/stable/modules/generated/sklearn.model_selection.RandomizedSearchCV.html
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from sklearn.ensemble import RandomForestClassifier
from sklearn.model_selection import RandomizedSearchCV
from scipy.stats import uniform
rfc = RandomForestClassifier(n_jobs=-1)
param_distributions = {
'max_features': uniform(0.6, 0.4),
'n_estimators': range(20, 401, 20),
'max_depth': range(5, 41, 5) + [None],
'min_samples_split': [0.01, 0.05, 0.1]
}
n_iter = 100
search = RandomizedSearchCV(estimator=rfc, param_distributions=param_distributions, n_iter=n_iter, n_jobs=-1, verbose=3)
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%time search.fit(X_small, y_small)
print(search.best_score_, search.best_params_)
Everything up to this point is what you would do when training locally. With larger amount of data it would take much longer.
Your Google Cloud Platform project id.
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project_id = 'YOUR-PROJECT-ID'
A Google Cloud Storage bucket belonging to your project created through either:
This bucket will be used for storing temporary data during Docker image building, for storing training data, and for storing trained models.
This can be an existing bucket, but we recommend you create a new one.
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bucket_name = 'YOUR-BUCKET-NAME'
Pick a cluster id for the cluster on Google Container Engine we will create. Preferably not an existing cluster to avoid affecting its workload.
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cluster_id = 'YOUR-CLUSTER-ID'
Choose a name for the image that will be running on the container.
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image_name = 'YOUR-IMAGE-NAME'
Choose a zone to host the cluster.
List of zones: https://cloud.google.com/compute/docs/regions-zones/
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zone = 'us-central1-b'
Change this only if you have customized the source.
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source_dir = 'source'
This step builds a Docker image using the content in the source/ folder. The image will be tagged with the provided image_name so the workers can pull it. The main script source/worker.py would retrieve a pickled GridSearchCV object from Cloud Storage and fit it to data on GCS.
Note: This step only needs to be run once the first time you follow these steps,
and each time you modify the codes in source/. If you have not modified source/ then
you can just re-use the same image.
Note: This could take a couple minutes. To monitor the build process: https://console.cloud.google.com/gcr/builds
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from helpers.cloudbuild_helper import build
build(project_id, source_dir, bucket_name, image_name)
This step creates a cluster on the Container Engine.
You can alternatively create the cluster with the gcloud command line tool or through the console, but
you must add the additional scope of write access to Google Clous Storage: 'https://www.googleapis.com/auth/devstorage.read_write'
Note: This could take several minutes. To monitor the cluster creation process: https://console.cloud.google.com/kubernetes/list
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from helpers.gke_helper import create_cluster
create_cluster(project_id, zone, cluster_id, n_nodes=1, machine_type='n1-standard-64')
For GCE instance pricing: https://cloud.google.com/compute/pricing
The GKEParallel class is a helper wrapper around a GridSearchCV object that manages deploying fitting jobs to the Container Engine cluster created above.
We pass in the GridSearchCV object, which will be pickled and stored on Cloud Storage with
uri of the form:
gs://YOUR-BUCKET-NAME/YOUR-CLUSTER-ID.YOUR-IMAGE-NAME.UNIX-TIME/search.pkl
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from sklearn.ensemble import RandomForestClassifier
from sklearn.model_selection import RandomizedSearchCV
from scipy.stats import uniform
rfc = RandomForestClassifier(n_jobs=-1)
param_distributions = {
'max_features': uniform(0.6, 0.4),
'n_estimators': range(20, 401, 20),
'max_depth': range(5, 41, 5) + [None],
'min_samples_split': [0.01, 0.05, 0.1]
}
n_iter = 100
search = RandomizedSearchCV(estimator=rfc, param_distributions=param_distributions, n_iter=n_iter, n_jobs=-1, verbose=3)
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from gke_parallel import GKEParallel
gke_search = GKEParallel(search, project_id, zone, cluster_id, bucket_name, image_name)
To make it easy to gain access to the cluster through the Kubernetes client library, included in this sample is a script that retrieves credentials for the cluster with gcloud and refreshes access token with kubectl.
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! bash get_cluster_credentials.sh $cluster_id $zone
GKEParallel instances implement a similar (but different!) interface as GridSearchCV.
Calling fit(X, y) first uploads the training data to Cloud Storage as:
gs://YOUR-BUCKET-NAME/YOUR-CLUSTER-ID.YOUR-IMAGE-NAME.UNIX-TIME/X.pkl
gs://YOUR-BUCKET-NAME/YOUR-CLUSTER-ID.YOUR-IMAGE-NAME.UNIX-TIME/y.pklThis allows reusing the same uploaded datasets for future training tasks.
For instance, if you already have pickled data on Cloud Storage:
gs://DATA-BUCKET/X.pkl
gs://DATA-BUCKET/y.pklthen you can deploy the fitting task with:
gke_search.fit(X='gs://DATA-BUCKET/X.pkl', y='gs://DATA-BUCKET/y.pkl')Calling fit(X, y) also pickles the wrapped search and gke_search, stores them on Cloud Storage as:
gs://YOUR-BUCKET-NAME/YOUR-CLUSTER-ID.YOUR-IMAGE-NAME.UNIX-TIME/search.pkl
gs://YOUR-BUCKET-NAME/YOUR-CLUSTER-ID.YOUR-IMAGE-NAME.UNIX-TIME/gke_search.pkl
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gke_search.fit(X_large, y_large)
In the background, the GKEParallel instance splits the param_grid into smaller param_grids
Each smaller param_grid is pickled and stored on GCS within each worker's workspace:
gs://YOUR-BUCKET-NAME/YOUR-CLUSTER-ID.YOUR-IMAGE-NAME.UNIX-TIME/WORKER-ID/param_grid.pkl
The param_distributions can be accessed as follows.
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gke_search.param_distributions
You could optionally specify a task_name when creating a GKEParallel instance.
If you did not specify a task_name, when you call fit(X, y) the task_name will be set to:
YOUR-CLUSTER-ID.YOUR-IMAGE-NAME.UNIX-TIME
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gke_search.task_name
Similarly, each job is given a job_name. The dictionary of job_names can be accessed as follows. Each worker pod handles one job processing one of the smaller param_grids.
To monitor the jobs: https://console.cloud.google.com/kubernetes/workload
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gke_search.job_names
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#gke_search.cancel()
GKEParallel instances implement a similar (but different!) interface as Future instances.
Calling done() checks whether each worker has completed the job and persisted its outcome
on GCS with uri:
gs://YOUR-BUCKET-NAME/YOUR-CLUSTER-ID.YOUR-IMAGE-NAME.UNIX-TIME/WORKER-ID/fitted_search.pkl
To monitor the jobs: https://console.cloud.google.com/kubernetes/workload
To access the persisted data directly: https://console.cloud.google.com/storage/browser/YOUR-BUCKET-NAME/
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gke_search.done(), gke_search.dones
When all the jobs are finished, the pods will stop running (but the cluster will remain), and we can retrieve the fitted model.
Calling result() will populate the gke_search.results attribute which is returned.
This attribute records all the fitted GridSearchCV from the jobs. The fitted model is downloaded only if the download argument is set to True.
Calling result() also updates the pickled gke_search object on Cloud Storage:
gs://YOUR-BUCKET-NAME/YOUR-CLUSTER-ID.YOUR-IMAGE-NAME.UNIX-TIME/gke_search.pkl
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result = gke_search.result(download=False)
You can also get the logs from the pods:
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from helpers.kubernetes_helper import get_pod_logs
for pod_name, log in get_pod_logs().items():
print('=' * 20)
print('\t{}\n'.format(pod_name))
print(log)
Once the jobs are finished, the cluster can be deleted. All the fitted models are stored on GCS.
The cluster can also be deleted from the console: https://console.cloud.google.com/kubernetes/list
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from helpers.gke_helper import delete_cluster
#delete_cluster(project_id, zone, cluster_id)
The next cell continues to poll the jobs until they are all finished, downloads the results, and deletes the cluster.
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import time
from helpers.gke_helper import delete_cluster
while not gke_search.done():
n_done = len([d for d in gke_search.dones.values() if d])
print('{}/{} finished'.format(n_done, len(gke_search.job_names)))
time.sleep(60)
delete_cluster(project_id, zone, cluster_id)
result = gke_search.result(download=True)
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from helpers.gcs_helper import download_uri_and_unpickle
gcs_uri = 'gs://YOUR-BUCKET-NAME/YOUR-CLUSTER-ID.YOUR-IMAGE-NAME.UNIX-TIME/gke_search.pkl'
gke_search_restored = download_uri_and_unpickle(gcs_uri)
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gke_search.best_score_, gke_search.best_params_, gke_search.best_estimator_
You can also call predict(), which deligates the call to the best_estimator_.
Below we calculate the accuracy on the 10000 test images.
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predicted = gke_search.predict(mnist.data[60000:])
print(len([p for i, p in enumerate(predicted) if p == mnist.target[60000:][i]]))
To clean up, delete the cluster so your project will no longer be charged for VM instance usage. The simplest way to delete the cluster is through the console: https://console.cloud.google.com/kubernetes/list
This will not delete any data persisted on Cloud Storage.