> ## Documentation Index
> Fetch the complete documentation index at: https://sitectl.libops.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Blazegraph component

> How to enable and disable the Blazegraph triple store in your Islandora stack.

Blazegraph is the RDF triple store that Islandora uses to power SPARQL queries and linked data indexing. In an Islandora stack, Blazegraph runs as a Docker service alongside Drupal and Fedora.

The `blazegraph` component controls whether Blazegraph is included in your stack. The LibOps template defaults to `disabled`; enable it for sites that need RDF indexing and SPARQL queries.

Supported dispositions:

| Disposition | Meaning                                                                        |
| ----------- | ------------------------------------------------------------------------------ |
| `enabled`   | Keep Blazegraph and triplestore indexing in the standard Islandora stack.      |
| `disabled`  | Remove the triplestore service and suppress triplestore indexing integrations. |

## Check current state

```bash theme={null}
sitectl component describe
```

The output shows whether `blazegraph` is on, off, or drifted.

## Enable Blazegraph

```bash theme={null}
sitectl set blazegraph enabled
```

This adds the Blazegraph service and `blazegraph-data` volume back to
`docker-compose.yml`, enables `ALPACA_TRIPLESTORE_INDEXER_ENABLED`, restores
Drupal's default triplestore namespace, and seeds any missing managed Drupal
triplestore action files. Existing action bodies are preserved while Blazegraph
remains enabled, but those files are component-owned lifecycle artifacts:
disabling Blazegraph removes them, and a later re-enable seeds the canonical
content again.

The Islandora plugin changes only Blazegraph's named reaction entries inside
the shared media, repository-content, and taxonomy context files. Unknown keys,
adjacent actions, and downstream policy in those files are preserved. Fedora's
reaction entries are owned independently by the `fcrepo` component, so all four
Fedora/Blazegraph enabled and disabled combinations are supported.

## Disable Blazegraph

```bash theme={null}
sitectl set blazegraph disabled
```

This removes the Blazegraph service and volume from `docker-compose.yml`,
disables Alpaca triplestore indexing, clears Drupal's default triplestore
namespace, removes the managed triplestore action files, and deletes only
Blazegraph's named reactions from the shared context files. Fedora reactions
and unrelated downstream configuration remain intact. A future
`docker compose up` will not start Blazegraph.

<Warning>
  Disabling Blazegraph removes the service from the Compose project definition. Any RDF data stored in Blazegraph is not deleted from disk immediately, but it will not be preserved through volume lifecycle commands. Back up your Blazegraph data before disabling on a site with content.
</Warning>

## Create flags

Choose the triplestore shape during `sitectl create isle`:

```bash theme={null}
sitectl create isle --blazegraph on
sitectl create isle --blazegraph off
```

## When to disable Blazegraph

Blazegraph is resource-intensive. Consider disabling it for:

* **Minimal development stacks:** when you're working on Drupal code that doesn't involve SPARQL or linked data
* **Stacks that have replaced Blazegraph:** some Islandora installations have moved to alternative triple stores; if yours has, you can disable Blazegraph here to remove it from the Compose project

If you're running a standard Islandora installation and using features that rely on RDF queries, Blazegraph should be on.