Why enable dedicated master node requires more than 10 instances?

terraform-community-modules / tf_aws_elasticsearch

[DEPRECATED] Use https://github.com/terraform-aws-modules/terraform-aws-opensearch

MIT License

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Why enable dedicated master node requires more than 10 instances? #46

Closed zhaoyi0113 closed 4 years ago

zhaoyi0113 commented 4 years ago

Thanks for creating this module and I'd like to know why enable dedicated master node requires more than 10 instances?.

https://github.com/terraform-community-modules/tf_aws_elasticsearch/blob/6b9bcca3780996e8f0639226fdcecc953bf29860/main.tf#L45

antonbabenko commented 4 years ago

Enable or disable dedicated master nodes. Dedicated master nodes increase cluster stability and are required for domains that have instance counts greater than 10. We recommend three dedicated master nodes for production domains.

From AWS docs.

I guess this was just the best guess by the module developers, and you can provide another value of dedicated_master_threshold it if you want.

zhaoyi0113 commented 4 years ago

Thanks for explaining.