Feature Drift

Fennel monitors the live probability distribution of all extracted features. It does so by measuring the mean and the standard deviation of the extracted feature values.

Changes in the probability distribution of a feature are usually indicative of one of the three scenarios:

1. Organic drift over time
2. Major changes to feature definitions
3. Newly introduced bugs

Either way, it's useful to be able to track the feature distribution. These distributions can be seen on Fennel console.

These distributions are also hosted on the Prometheus endpoint. Thus you can point your monitoring systems (like Grafana) towards these graphs and do your own anomaly detection and/or alerting on top if needed.