> ## Documentation Index
> Fetch the complete documentation index at: https://firebolt-aggregate-helm-docs-pr-79.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Engine overview

> Create, operate, and inspect Firebolt Engines.

A `FireboltEngine` runs the compute nodes that serve queries. Every Engine references a ready `FireboltInstance` in the same namespace and may reference a `FireboltEngineClass` for shared defaults.

Use the Engine guides to operate the workload:

* [Engine scaling](./engine-scaling) covers replica changes, stopping and resuming, image updates, and rollout progress.
* [Engine rollouts](./engine-rollouts) covers graceful and recreate strategies, readiness, drain checks, and capacity planning.
* [Auto-stop and wake-up](./auto-stop-and-wake-up) covers activity-based scale-down and Gateway-triggered wake-up.
* [Object storage](./object-storage/amazon-s3) covers managed-table storage configuration.

For every field, phase, and condition, see the [FireboltEngine CRD reference](../crd-reference/engine-crd-reference).

## Inspect Engine status

```bash theme={"theme":{"light":"css-variables","dark":"css-variables"}}
kubectl get fireng -n firebolt
```

```text theme={"theme":{"light":"css-variables","dark":"css-variables"}}
NAME        REPLICAS   PHASE    READY   GENERATION   AGE
my-engine   5          stable   True    2            24h
```

Use `kubectl describe` to inspect conditions and Kubernetes events:

```bash theme={"theme":{"light":"css-variables","dark":"css-variables"}}
kubectl describe fireng my-engine -n firebolt
```

An Engine is available when its phase is `stable` and its `Ready` condition is `True`. The transition phases `creating`, `switching`, `draining`, and `cleaning` indicate rollout progress. A phase of `stopped` means `spec.replicas` is `0` and the Engine is intentionally unavailable.

Worked manifests are available in the [`examples/`](https://github.com/firebolt-db/firebolt-kubernetes-operator/tree/main/examples) directory.