AWS ElasticSearch shrink API node name

Question

AWS Docs for AWS ElasticSearch have a section about the shrink API:

https://docs.aws.amazon.com/elasticsearch-service/latest/developerguide/aes-supported-es-operations.html#es_version_api_notes-shrink

The sample shows how to shrink:

{
  "settings": {
    "index.routing.allocation.require._name": "name-of-the-node-to-shrink-to",
    "index.blocks.read_only": true
  }
}

PUT https://domain.region.es.amazonaws.com/source-index/_settings
{
  "settings": {
    "index.routing.allocation.require._name": null,
    "index.blocks.read_only": false
  }
}

PUT https://domain.region.es.amazonaws.com/shrunken-index/_settings
{
  "settings": {
    "index.routing.allocation.require._name": null,
    "index.blocks.read_only": false
  }
}

Where do I get the name-of-the-node-to-shrink-to, source-index and shrunken-index?

Answer 1

For shrink operation:

All primary shards for the index must reside on the same node. https://www.elastic.co/guide/en/elasticsearch/reference/master/indices-shrink-index.html

"name-of-the-node-to-shrink-to" parameter relocates the index’s shards to this particular node.

You can get the nodes name for your cluster using the cat nodes API:

GET /_cat/nodes?v&h=name

Next, your source-index in the index that you want to perform shrink operation on. This process creates a new target index which will be your shrunken-index

You will make the following API call to perform the shrink operation:

POST /my_source_index/_shrink/my_target_index
{
  "settings": {
    "index.routing.allocation.require._name": null, 
    "index.blocks.write": null 
  }
}

The other two calls that you see in the AWS documentation are for clearing the allocation requirement for the source-index and shrunken-index

You can also follow Elastic's guide on the same.