> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/gridgain/gridgain-9/architecture/storage/engines/rocksdb-persistent-storage.md).

# RocksDB Persistent Storage

Configure the experimental GridGain 9 RocksDB persistent storage engine, based on an LSM tree and suited to high write throughput.

RocksDB is a persistent storage engine based on LSM tree. It is best used in environments with a large number of write requests.

{% hint style="info" %}
RocksDB storage currently is considered as experimental.
{% endhint %}

## Profile Configuration

Each GridGain storage engine can have several storage profiles. Each profile has the following properties:

| Property             | Default             | Description                                                        |
| -------------------- | ------------------- | ------------------------------------------------------------------ |
| engine               |                     | The name of the storage engine.                                    |
| sizeBytes            | `256 * 1024 * 1024` | Sets the space allocated to the storage profile, in bytes.         |
| writeBufferSizeBytes | `64 * 1024 * 1024`  | Size of rocksdb write buffer.                                      |
| numShardBits         | `-1`                | The cache is sharded to 2^numShardBits shards, by hash of the key. |

## Configuration Example

In GridGain 9, you can create and maintain configuration in either HOCON or JSON. The configuration file has a single root "node," called `ignite`. All configuration sections are children, grandchildren, etc., of that node. The example below shows how to configure a storage profile with RocksDB storage:

```json
{
  "ignite" : {
    "storage" : {
      "profiles" : [
        {
          "name" : "rocks_profile",
          "engine" : "rocksDb",
          "sizeBytes" : 2560000
        }
      ]
    }
  }
}
```

You can then use the profile (in this case, `rocks_profile`) in your distribution zone configuration.