[BUG] KNN search example returns "unknown setting [index.knn]"

[joshuajnoble]

What is the bug?

A clear and concise description of the bug.

With OpenSearch 3.1 and opensearch-py 3.0.0 when I try to run the knn_basics.py sample, I get the following error:

opensearchpy.exceptions.RequestError: RequestError(400, 'settings_exception', 'unknown setting [index.knn] please check that any required plugins are installed or check the breaking changes documentation for removed settings.

I can create other types of indices, but not knn.

I also get 400 errors when I try to search using knn queries.

How can one reproduce the bug?

Steps to reproduce the behavior.

Create an index with

"settings": {"index.knn": True}

What is the expected behavior?

A clear and concise description of what you expected to happen.

I can create the index.

What is your host/environment?

Operating system, version.

OSX 15.5

Do you have any screenshots?

If applicable, add screenshots to help explain your problem.

Do you have any additional context?

Add any other context about the problem.

[andrross]

Catch All Triage - 1 2