MLServer has been built with Multi-Model Serving (MMS) in mind. This means that, within a single instance of MLServer, you can serve multiple models under different paths. This also includes multiple versions of the same model.
This notebook shows an example of how you can leverage MMS with MLServer.
We will first start by training 2 different models:
Name | Framework | Source | Trained Model Path |
---|---|---|---|
mnist-svm |
scikit-learn |
MNIST example from the scikit-learn documentation |
./models/mnist-svm/model.joblib |
mushroom-xgboost |
xgboost |
Mushrooms example from the xgboost Getting Started guide |
./models/mushroom-xgboost/model.json |
# Original source code and more details can be found in:
# https://scikit-learn.org/stable/auto_examples/classification/plot_digits_classification.html
# Import datasets, classifiers and performance metrics
from sklearn import datasets, svm, metrics
from sklearn.model_selection import train_test_split
# The digits dataset
digits = datasets.load_digits()
# To apply a classifier on this data, we need to flatten the image, to
# turn the data in a (samples, feature) matrix:
n_samples = len(digits.images)
data = digits.images.reshape((n_samples, -1))
# Create a classifier: a support vector classifier
classifier = svm.SVC(gamma=0.001)
# Split data into train and test subsets
X_train, X_test_digits, y_train, y_test_digits = train_test_split(
data, digits.target, test_size=0.5, shuffle=False)
# We learn the digits on the first half of the digits
classifier.fit(X_train, y_train)
import joblib
import os
mnist_svm_path = os.path.join("models", "mnist-svm")
os.makedirs(mnist_svm_path, exist_ok=True)
mnist_svm_model_path = os.path.join(mnist_svm_path, "model.joblib")
joblib.dump(classifier, mnist_svm_model_path)
# Original code and extra details can be found in:
# https://xgboost.readthedocs.io/en/latest/get_started.html#python
import os
import xgboost as xgb
import requests
from urllib.parse import urlparse
from sklearn.datasets import load_svmlight_file
TRAIN_DATASET_URL = 'https://raw.githubusercontent.com/dmlc/xgboost/master/demo/data/agaricus.txt.train'
TEST_DATASET_URL = 'https://raw.githubusercontent.com/dmlc/xgboost/master/demo/data/agaricus.txt.test'
def _download_file(url: str) -> str:
parsed = urlparse(url)
file_name = os.path.basename(parsed.path)
file_path = os.path.join(os.getcwd(), file_name)
res = requests.get(url)
with open(file_path, 'wb') as file:
file.write(res.content)
return file_path
train_dataset_path = _download_file(TRAIN_DATASET_URL)
test_dataset_path = _download_file(TEST_DATASET_URL)
# NOTE: Workaround to load SVMLight files from the XGBoost example
X_train, y_train = load_svmlight_file(train_dataset_path)
X_test_agar, y_test_agar = load_svmlight_file(test_dataset_path)
X_train = X_train.toarray()
X_test_agar = X_test_agar.toarray()
# read in data
dtrain = xgb.DMatrix(data=X_train, label=y_train)
# specify parameters via map
param = {'max_depth':2, 'eta':1, 'objective':'binary:logistic' }
num_round = 2
bst = xgb.train(param, dtrain, num_round)
bst
import os
mushroom_xgboost_path = os.path.join("models", "mushroom-xgboost")
os.makedirs(mushroom_xgboost_path, exist_ok=True)
mushroom_xgboost_model_path = os.path.join(mushroom_xgboost_path, "model.json")
bst.save_model(mushroom_xgboost_model_path)
The next step will be serving both our models within the same MLServer instance.
For that, we will just need to create a model-settings.json
file local to each of our models and a server-wide settings.json
.
That is,
settings.json
: holds the configuration of our server (e.g. ports, log level, etc.).models/mnist-svm/model-settings.json
: holds the configuration specific to ourmnist-svm
model (e.g. input type, runtime to use, etc.).models/mushroom-xgboost/model-settings.json
: holds the configuration specific to ourmushroom-xgboost
model (e.g. input type, runtime to use, etc.).
%%writefile settings.json
{
"debug": "true"
}
%%writefile models/mnist-svm/model-settings.json
{
"name": "mnist-svm",
"implementation": "mlserver_sklearn.SKLearnModel",
"parameters": {
"version": "v0.1.0"
}
}
%%writefile models/mushroom-xgboost/model-settings.json
{
"name": "mushroom-xgboost",
"implementation": "mlserver_xgboost.XGBoostModel",
"parameters": {
"version": "v0.1.0"
}
}
Now that we have our config in-place, we can start the server by running mlserver start .
. This needs to either be ran from the same directory where our config files are or pointing to the folder where they are.
mlserver start .
Since this command will start the server and block the terminal, waiting for requests, this will need to be ran in the background on a separate terminal.
By this point, we should have both our models getting served by MLServer. To make sure that everything is working as expected, let's send a request from each test set.
For that, we can use the Python types that the mlserver
package provides out of box, or we can build our request manually.
import requests
x_0 = X_test_digits[0:1]
inference_request = {
"inputs": [
{
"name": "predict",
"shape": x_0.shape,
"datatype": "FP32",
"data": x_0.tolist()
}
]
}
endpoint = "http://localhost:8080/v2/models/mnist-svm/versions/v0.1.0/infer"
response = requests.post(endpoint, json=inference_request)
response.json()
import requests
x_0 = X_test_agar[0:1]
inference_request = {
"inputs": [
{
"name": "predict",
"shape": x_0.shape,
"datatype": "FP32",
"data": x_0.tolist()
}
]
}
endpoint = "http://localhost:8080/v2/models/mushroom-xgboost/versions/v0.1.0/infer"
response = requests.post(endpoint, json=inference_request)
response.json()