rmqtt-session-storage 0.23.1

[**English**](README.md) | [简体中文](README-CN.md)

# rmqtt-session-storage


[![crates.io](https://img.shields.io/crates/v/rmqtt-session-storage.svg)](https://crates.io/crates/rmqtt-session-storage)

Session persistence plugin. Stores client session state using Sled, Redis, or Redis Cluster backends.

## Usage


```toml
[dependencies]
rmqtt-session-storage = "0.21"
```

```rust
rmqtt_session_storage::register(&scx, true, false).await?;
```

## Configuration


File: `rmqtt-session-storage.toml`

### Storage Type


| Option | Type | Default | Description |
|--------|------|---------|-------------|
| `storage.type` | string | `"sled"` | Backend storage type: `sled`, `redis`, or `redis-cluster` |

### Sled Backend


| Option | Type | Default | Description |
|--------|------|---------|-------------|
| `storage.sled.path` | string | `"/var/log/rmqtt/.cache/session/{node}"` | Sled database file path (`{node}` = node ID placeholder) |
| `storage.sled.cache_capacity` | string | `"3G"` | Sled cache capacity |

### Redis Backend


| Option | Type | Default | Description |
|--------|------|---------|-------------|
| `storage.redis.url` | string | `"redis://127.0.0.1:6379/"` | Redis server URL |
| `storage.redis.prefix` | string | `"session-{node}"` | Key prefix (`{node}` = node ID placeholder) |

### Redis Cluster Backend


| Option | Type | Default | Description |
|--------|------|---------|-------------|
| `storage.redis-cluster.urls` | array of string | `["redis://127.0.0.1:6380/", ...]` | Redis cluster node URLs |
| `storage.redis-cluster.prefix` | string | `"session-{node}"` | Key prefix |

### Circuit Breaker


Protects the broker from blocking when the storage backend becomes unreachable.
The breaker uses a sliding window to track the call failure rate. When the failure
rate exceeds the threshold and the minimum number of calls has been reached, the
circuit trips to OPEN and all session storage operations fast-fail.

| Option | Type | Default | Description |
|--------|------|---------|-------------|
| `backend_timeout` | `string` | `"15s"` | Backend storage operation timeout (`"0s"` to disable) |

## Dependencies


`rmqtt` (feature `plugin`), `sled`, `redis`, `tokio`

## License


MIT OR Apache-2.0