+++
title = "Enable alerting high availability"
description = "Enable alerting high availability"
keywords = ["grafana", "alerting", "tutorials", "ha", "high availability"]
weight = 450
+++

# Enable alerting high availability

You can enable [alerting high availability]({{< relref "./_index.md" >}}) support by updating the Grafana configuration file. On Kubernetes, you can enable alerting high availability by updating the Kubernetes container definition.

## Update Grafana configuration file

### Before you begin

Since gossiping of notifications and silences uses both TCP and UDP port `9094`, ensure that each Grafana instance is able to accept incoming connections on these ports.

**To enable high availability support:**

1. In your custom configuration file ($WORKING_DIR/conf/custom.ini), go to the `[unified_alerting]` section.
2. Set `[ha_peers]` to the number of hosts for each Grafana instance in the cluster (using a format of host:port), for example, `ha_peers=10.0.0.5:9094,10.0.0.6:9094,10.0.0.7:9094`.
   You must have at least one (1) Grafana instance added to the [`[ha_peer]` section.
3. Set `[ha_listen_address]` to the instance IP address using a format of `host:port` (or the [Pod's](https://kubernetes.io/docs/concepts/workloads/pods/) IP in the case of using Kubernetes).
   By default, it is set to listen to all interfaces (`0.0.0.0`).

## Update Kubernetes container definition

If you are using Kubernetes, you can expose the pod IP [through an environment variable](https://kubernetes.io/docs/tasks/inject-data-application/environment-variable-expose-pod-information/) via the container definition such as:

```bash
env:
- name: POD_IP
  valueFrom:
    fieldRef:
      fieldPath: status.podIP
```