feat: Add materialization, feature freshness, request latency, and push metrics to feature server by ntkathole · Pull Request #6071 · feast-dev/feast

ntkathole · 2026-03-05T08:57:51Z

What this PR does / why we need it:

Adds rich Prometheus metrics to the Feast feature server covering areas that previously had no observability:

Request latency histograms with feature_count and feature_view_count labels so operators can correlate latency with request complexity
Materialization tracking — success/failure counters and duration histograms per feature view
Feature freshness gauges — staleness (seconds since last materialization) per feature view, updated via background polling
Online feature retrieval counters — request counts and entity-row-per-request histograms
Push request counters — tracked by push source and mode (online/offline)
CPU and memory gauges — moved from inline code to the shared metrics module
Previously the feature server only had inline CPU/memory monitoring. This PR introduces 10 new metric families covering the full request lifecycle, materialization pipeline, and data freshness.

New metrics

Metric	Type	Labels
`feast_feature_server_request_total`	Counter	`endpoint`, `status`
`feast_feature_server_request_latency_seconds`	Histogram	`endpoint`, `feature_count`, `feature_view_count`
`feast_online_features_request_total`	Counter	—
`feast_online_features_entity_count`	Histogram	—
`feast_push_request_total`	Counter	`push_source`, `mode`
`feast_materialization_total`	Counter	`feature_view`, `status`
`feast_materialization_duration_seconds`	Histogram	`feature_view`
`feast_feature_freshness_seconds`	Gauge	`feature_view`, `project`
`feast_feature_server_cpu_usage`	Gauge	—
`feast_feature_server_memory_usage`	Gauge	—

Configuration

Metrics are fully opt-in with zero overhead when disabled. Enable via CLI or YAML:

feature_server:
  metrics:
    enabled: true
    resource: true          # CPU / memory gauges
    request: true           # endpoint latency & request counters
    online_features: true   # online feature retrieval counters
    push: true              # push request counters
    materialization: true   # materialization counters & duration
    freshness: true         # per-feature-view freshness gauges

Per-category toggles let disable specific metric groups (e.g., keep CPU/memory but skip request latency). All categories default to true. The --metrics CLI flag works without any YAML config.

astefanutti · 2026-03-05T13:30:54Z

docs/reference/feature-servers/python-feature-server.md

+        metrics: true
+```
+
+The operator automatically exposes port 8000 and creates the corresponding


Should the operator also create the PodMonitor / ServiceMonitor resource owned by the FeatureStore resource for Prometheus operator to discover the metrics endpoint and configure the scraping?

That would be a good enhancement, we can have CRD detection guard to avoid crashing on vanilla Kubernetes clusters without the Prometheus Operator. Will raise an issue for this.

…sh metrics to feature server Signed-off-by: ntkathole <nikhilkathole2683@gmail.com>

ntkathole requested a review from a team as a code owner March 5, 2026 08:57