> ## Documentation Index
> Fetch the complete documentation index at: https://docs-v2.ard.co/llms.txt
> Use this file to discover all available pages before exploring further.

# HAProxy on cluster-n03 / cluster-n04

> HAProxy versions and roles on the n03/n04 databases cluster.

## HAProxy topology

HAProxy runs on both nodes of the databases cluster and fronts various backends (databases and potentially other internal services):

* `cluster-n03` – older HAProxy 1.6.3
* `cluster-n04` – newer HAProxy 2.0.13

Both services are enabled and actively running, giving flexibility for routing traffic through either node.

## HAProxy on cluster-n03

* **Version**: `HA-Proxy version 1.6.3 2015/12/25`
* **Service**: `haproxy.service` (enabled, active)
* **Config file**: `/etc/haproxy/haproxy.cfg`

Useful commands:

```bash theme={null}
ssh cluster-n03
systemctl status haproxy
haproxy -c -f /etc/haproxy/haproxy.cfg
```

## HAProxy on cluster-n04

* **Version**: `HA-Proxy version 2.0.13-2ubuntu0.3 2021/08/27`
* **Service**: `haproxy.service` (enabled, active)
* **Config file**: `/etc/haproxy/haproxy.cfg`

Useful commands:

```bash theme={null}
ssh cluster-n04
systemctl status haproxy
haproxy -c -f /etc/haproxy/haproxy.cfg
```

## Notes

* Exact frontend/backend definitions (which ports and backends are configured) live in `/etc/haproxy/haproxy.cfg` on each host.
* Applications typically hit HAProxy frontends instead of talking directly to database ports, but Redis currently bypasses HAProxy (see the Redis page).