# Set up high availability data to Amazon Managed Service for Prometheus using the Prometheus Operator Helm chart
Set up high availability metrics with the Prometheus Operator

To set up a high availability configuration with the Prometheus Operator in Helm, you must apply external labels on all instances of a high availability group, so Amazon Managed Service for Prometheus can identify them. You also must set the attributes `replicaExternalLabelName` and `externalLabels` on the Prometheus Operator Helm chart.

**Example: YAML header**

In the following YAML header, `cluster` is added to `externalLabel` to identify a Prometheus instance agent as part of a high-availability group, and `replicaExternalLabels` identifies each replica in the group.

```
replicaExternalLabelName: __replica__
externalLabels:
cluster: prom-dev
```

**Note**  
Certain versions of Kubernetes (1.28 and 1.29) may emit their own metric with a `cluster` label. This can cause issues with Amazon Managed Service for Prometheus deduplication. See the [High availability FAQ](HA_FAQ.md#HA_FAQ_cluster-label) for more information.