# Getting Started

## Installing VerneMQ

VerneMQ is a high-performance, distributed MQTT message broker. It scales horizontally and vertically on commodity hardware to support a high number of concurrent publishers and consumers while maintaining low latency and fault tolerance. To use it, run VerneMQ using our Docker image:

* [Docker](https://courier-gojek.gitbook.io/vernemq/installing-vernemq/docker)

{% hint style="info" %}
This new version of VerneMQ now also requires redis for its operation. Refer [new message passing model](https://courier-gojek.gitbook.io/vernemq/configuring-vernemq/messagepassing) for its configuration.
{% endhint %}

## Starting VerneMQ

{% hint style="info" %}
If you built VerneMQ from sources, you can add the `/bin` directory of your VerneMQ release to `PATH`. For example, if you compiled VerneMQ in the `/home/vernemq` directory, then add the binary directory (`/home/vernemq/_build/default/rel/vernemq/bin`) to your PATH, so that VerneMQ commands can be used in the same manner as with a packaged installation.
{% endhint %}

To start a VerneMQ broker, use the vernemq start command in your Shell:

```
vernemq start
```

A successful start will return no output. If there is a problem starting the broker, an error message is printed to `STDERR`.

To run VerneMQ with an attached interactive Erlang console:

```
vernemq console
```

A VerneMQ broker is typically started in console mode for debugging or troubleshooting purposes. Note that if you start VerneMQ in this manner, it is running as a foreground process that will exit when the console is closed.

You can close the console by issuing this command at the Erlang prompt:

```
q().
```

Once your broker has started, you can initially check that it is running with the vernemq ping command:

```
vernemq ping
```

The command will respond with `pong` if the broker is running or `Node <NodeName> not responding to pings` in case it’s not.

{% hint style="warning" %}
As you may have noticed, VerneMQ will warn you at startup when your system’s open files limit (`ulimit -n`) is too low. You’re advised to increase the OS default open files limit when running VerneMQ. Read more about why and how in the [Open Files Limit documentation](https://courier-gojek.gitbook.io/vernemq/guides/change-open-file-limits).
{% endhint %}