> For the complete documentation index, see [llms.txt](https://awsnotes.dendron.so/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://awsnotes.dendron.so/analytics/amazon-opensearch-service/topics/general-reference.md).

# General reference

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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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## Supported instance types

* **Tip**\
  We often recommend different instance types for [dedicated master nodes](https://github.com/kevinslin/aws-reference-notes/blob/main/services/amazon_open_search_service/managedomains-dedicatedmasternodes.md) and data nodes.

## Reserved Instances

* **Note**\
  `StartTime` is Unix epoch time, which is the number of seconds that have passed since midnight UTC of 1 January 1970. For example, 1522872571 epoch time is 20:09:31 UTC of 4 April 2018. You can use online converters.