ElasticsearchAutoscaler documentation is unclear on supported node roles

[brsolomon-deloitte]

The ECK documentation on ElasticsearchAutoscaler is unclear as to which node roles it supports.

First it states:

Currently, autoscaling is supported for Elasticsearch data tiers and machine learning nodes.

Perhaps I am misreading, but this seems to imply that the autoscaling API, and hence ElasticsearchAutoscaler, only supports data nodes or machine learning nodes, and does not support e.g. ingest nodes.

But then it gives this example:

spec:
  ...
  policies:
    - name: data-ingest
      roles: ["data", "ingest" , "transform"]

...which seems to indicate that nodes other than data nodes are supported.

• ECK version:

  2.5.0

[thbkrkr]

I admit that it is a bit ambiguous. The autoscaling policies only applies to nodes that have at least data or exactly ml role.

In the example, nodes with roles ["data", "ingest", "transform"] are data nodes and also ingest and transform nodes, they are not just specialized data.

nodes.roles	supported?
["data"]	:heavy_check_mark:
["data", "ingest" , "transform"]	:heavy_check_mark:
["ml"]	:heavy_check_mark:
["ingest" , "transform"]	:x:
["data", "ml"]	:x:
["data", "ml", "ingest" , "transform"]	:x:
["ml", "ingest"]	:x:

Note that you can't autoscale nodes with roles data and ml. There is a validation rule to detect that ML nodes must be in a dedicated autoscaling policy.

I'll see to remove the ambiguity from the doc and maybe add validation for this.

[Hythloday-zero]

This is still catching folks off-guard. Any movement on amending the docs page on this??