# Best practices

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This page was generated from content adapted from the [AWS Developer Guide](https://github.com/awsdocs/amazon-opensearch-service-developer-guide.git)
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## Sizing domains

* **Tip**\
  For a summary of the hardware resources that are allocated to each instance type, see [Amazon OpenSearch Service pricing](https://aws.amazon.com/opensearch-service/pricing/).

## Dedicated master nodes

* **Note**\
  If your cluster doesn't have the necessary quorum to elect a new master node, write *and* read requests to the cluster both fail. This behavior differs from the OpenSearch default.

## Recommended CloudWatch alarms

* **Note**\
  If you deploy the CloudFormation stack, the `KMSKeyError` and `KMSKeyInaccessible` alarms will exists in an `Insufficient Data` state because these metrics only appear if a domain encounters a problem with its encryption key.
* **Note**\
  If you just want to *view* metrics, see [Monitoring OpenSearch cluster metrics with Amazon CloudWatch](https://github.com/kevinslin/aws-reference-notes/blob/main/services/amazon_open_search_service/managedomains-cloudwatchmetrics.md).