---
title: Backfill
order: 19
description: "The recent history the daemon replays to a dashboard on connect, so its charts start populated instead of empty. It is served from a bounded ring buffer of the last few hundred samples."
tags: [glossary, execution-and-caching]
---

# Backfill

The recent history the daemon replays to a dashboard on connect, so its charts
start populated instead of empty. It is served from a bounded ring buffer of the
last few hundred samples.

## Elsewhere

In data engineering a backfill recomputes a pipeline over a past date range (an Airflow
backfill). The magus backfill computes nothing: it replays samples the daemon already holds.

## Example

The console's dashboard receives the backfill when it connects to the daemon.

```sh
magus server start
```

## Used in

<!-- BEGIN GLOSSARY USAGE (generated by glossary-usage-generate from the knowledge graph; edit the generator, not this list) -->

In the docs:

- [Backfill](../reference/api/metrics/v1alpha1/metrics.md#backfill)

<!-- END GLOSSARY USAGE -->

## See also

- [The broker and the daemon](../guides/integrations/server.md)
- [Snapshot](snapshot.md)