OpenSearch Read Only Index

If you prefer to watch a video instead of reading the instructions below, check out the link below

YouTube video - https://youtu.be/45T49W9DHo4

Overview

OpenSearch indices can be set to read only ie. all write requests will throw an exception and be blocked. There are multiple reasons why you would want to make an index read only. One reason is before running certain back end operations such as a force merge it is recommended to make an index read only.

The instructions below demonstrate how to make an index read only and the enable writes again.

Set an Index to Read Only

Running

PUT sample-data/_settings
{
  "index": {
    "blocks.read_only": true
  }
}

Will set the index sample-data to read only. After running the API call above if you try to write a document to the index you will receive an error

Disable Read Only (ie. enable writes)

To re-enable writes or disable read only you can run the following API call

PUT sample-data/_settings
{
  "index": {
    "blocks.read_only": false
  }
}

Once read only is false, you can again write data to the index