[DOC] Reference ZSTD Codecs as optional plugin

[sarthakaggarwal97]

What do you want to do?

• Request a change to existing documentation
• Add new documentation
• Report a technical problem with the documentation
• Other

Tell us about your request. Provide a summary of the request and all versions that are affected.
Following recent discussions with respect to this issue, it would be required to inform the users that codecs are still in optional plugin, experimental or feature flag based.

Docs to be changed:

1. https://opensearch.org/docs/latest/im-plugin/index-codecs/
2. https://opensearch.org/docs/latest/tuning-your-cluster/performance/

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.

[hdhalter]

Hi @kolchfa-aws , since you are familiar with this content, can you please update the doc? Thanks.

[sarthakaggarwal97]

Closing this issue since we are not making this feature experimental for now. Thanks @kolchfa-aws @hdhalter

[dblock]

1. In 2.10 the ZSTD plugin is not installed by default like in 2.9.
2. If we do [Onboarding] [2.10.0] Install custom-codecs plugin (zstd compression) in 2.10 distribution opensearch-build#3971 it will be installed in the full distribution but not in the min distribution.

Either way this is a breaking change and needs to be documented, reopening.

[hdhalter]

@dblock - Is there someone that can create a PR?

[andrross]

Either way this is a breaking change and needs to be documented, reopening.

@dblock There are many examples in the documentation of installed-by-default plugin functionality being described without mention that it is a plugin that can be uninstalled. (e.g. Aysnc search) What specifically do you think needs to be documented here (assuming the plugin is installed by default)?

[dblock]

IMO the change to users for the min distribution - installed in 2.9, not installed in 2.10. But I am not sure whether we say anything about that anywhere?

[andrross]

At a minimum we should add it to the list of bundled plugins: #5000

@hdhalter Can someone take a look here?

[kolchfa-aws]

Thanks, @andrross! Is there any more work needed for this issue or is it fixed by #5000?

[andrross]

@kolchfa-aws, I don't have any other specific suggestions to change other than what is done by #5000