# Redis Pub/Sub

> Aside from data storage, [Redis](https://redis.io/) can be used as a Publisher/Subscriber platform. In this pattern, publishers can issue messages to any number of subscribers on a channel. These messages are fire-and-forget, in that if a message is published and no subscribers exists, the message evaporates and cannot be recovered.

## Installation

Before the usage remember to install required packages.

```bash
$ yarn add redis
```

## Overview

{% tabs %}
{% tab title="microservice.ts" %}

```typescript
import { createMicroservice, Transport } from '@marblejs/messaging';

const microservice = createMicroservice({
  transport: Transport.REDIS
  options: {
    host: 'redis://127.0.0.1:6379',
    channel: 'hello_channel',
  },
  // ...
});
```

{% endtab %}

{% tab title="client.ts" %}

```typescript
import { MessagingClient, createMicroservice, Transport } from '@marblejs/messaging';

const client = MessagingClient({
  transport: Transport.REDIS
  options: {
    host: 'redis://127.0.0.1:6379',
    channel: 'hello_channel',
  },
  // ...
});
```

{% endtab %}
{% endtabs %}

The `options` property is specific to the chosen transport layer. **REDIS** exposes the following properties:

| Attribute  | description                                                     |
| ---------- | --------------------------------------------------------------- |
| `host`     | Host address of the Redis server                                |
| `channel`  | Channel name which your microservice will listen to             |
| `timeout`  | Timeout for RPC-like communication. Defaults to **120 seconds** |
| `port`     | Port of the Redis server                                        |
| `password` | If set, client will run Redis auth command on connect.          |