🗂 Get your data from a Feature Store

Feature stores allow data teams to serve data via an offline store and an online low-latency store where data is kept in sync between the two. It also offers a centralized registry where features (and feature schemas) are stored for use within a team or wider organization.

As a data scientist working on training your model, your requirements for how you access your batch / 'offline' data will almost certainly be different from how you access that data as part of a real-time or online inference setting. Feast solves the problem of developing train-serve skew where those two sources of data diverge from each other.

Feature stores are a relatively recent addition to commonly-used machine learning stacks. Feast is a leading open-source feature store, first developed by Gojek in collaboration with Google.

This example runs locally, using a (local) Redis server to simulate the online part of the store.

🗺 Features Stores & ZenML

There are two core functions that feature stores enable: access to data from an offline / batch store for training and access to online data at inference time. The ZenML Feast integration enables both of these behaviors.

This example showcases a local implementation where the whole setup runs on a single machine, but we assume that users of the ZenML Feast integration will have set up their own feature store already. We encourage users to check out Feast's documentation and guides on how to setup your offline and online data sources via the configuration yaml file.

This example currently shows the offline data retrieval part of what Feast enables. (Online data retrieval is currently possible in a local / simple setting, but we don't currently support using the online data serving in the context of a deployed model or as part of model deployment.)

🧰 How the example is implemented

This example has two simple steps, showing how you can access historical (batch / offline) data from a local file source.

🖥 Run it locally

👣 Step-by-Step

📄 Prerequisites

In order to run this example, you need to install and initialize ZenML:

# install CLI
pip install zenml

# install ZenML integration
zenml integration install feast

Since this example is built around a Redis use case, a Python package to interact with Redis will get installed alongside Feast, but you will still first need to install Redis yourself. See this page for some instructions on how to do that on your operating system.

You will then need to run a Redis server in the background in order for this example to work. You can either use the redis-server command in your terminal (which will run a continuous process until you CTRL-C out of it), or you can run the daemonized version:

redis-server --daemonize yes

# verify it is running (Unix machines)
ps aux | grep redis-server

Once Redis is up and running, you can access the example code and setup in the following way:

# pull example
zenml example pull feast_feature_store
cd zenml_examples/feast_feature_store

# Initialize ZenML repo
zenml init

You then should setup the Feast feature store stack component and activate it as part of your current working stack:

# register the feature store stack component
zenml feature-store register feast_store --flavor=feast --feast_repo="./feast_feature_repo"

# register and activate the feature store stack
zenml stack register fs_stack -m default -o default -a default -f feast_store --set

# view the current active stack
zenml stack describe

The final step is to apply the configuration of your feature store (listed in the feast_feature_repo/feature_store.yaml file) by entering the following commands:

cd feast_feature_repo
feast apply

You should see some acknowledgment that an entity and a feature view has been registered and that infrastructure has been deployed.

▶️ Run the Code

Now we're ready. Execute:

cd ..
python run.py

🧽 Clean up

In order to clean up, delete the remaining ZenML references.

rm -rf zenml_examples

If you ran the Redis server as a daemon process, you'll want to find the process ID (using ps aux | grep redis-server) and you can kill the process from the terminal.

📜 Learn more

Our docs regarding the Feast feature store integration can be found here.