Switch built-in ILM rollover policies from max_size to max_primary_shard_size

[rodrigc]

Motivation/summary

In the Kibana UI, when looking at ILM policies related to apm-server, I see warnings:

Maximum index size is deprecated and will be removed in a future version. Use maximum primary shard size instead.

To avoid confusion for the end-user, I recommend that the same changes which were done in elasticsearch's default ILM policies be done for apm-server:

Related to:

• Enhance rollover API and ILM rollover action to specify max single primary shard size elasticsearch#63026
• Switch built-in policies to max_primary_shard_size elasticsearch#69995 by @joegallo

Checklist

• Update CHANGELOG.asciidoc

Related issues

Fixes: #11728

[mergify]

This pull request does not have a backport label. Could you fix it @rodrigc? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-7.17 is the label to automatically backport to the 7.17 branch.
• backport-8./d is the label to automatically backport to the 8./d branch. /d is the digit.

NOTE: backport-skip has been added to this pull request.

[kruskall]

For reviewers: elastic/kibana#96545

[rodrigc]

I needed to remove the EOL markers that my editor added to the json files, otherwise elastic-package would complain that the files were not formatted.

[rodrigc]

I added a changelog entry to appease the elasticsearch-ci/docs workflow check

[rodrigc]

How can I make the elasticsearch-ci/docs automation pass?
I thought that adding an entry to changelogs/head.asciidoc was enough, but looks like it is not.

[axw]

/run elasticsearch-ci/docs

[axw]

How can I make the elasticsearch-ci/docs automation pass?

@rodrigc the docs CI only runs for Elastic employee PRs by default for security reasons. I've prodded it into action.

[rodrigc]

Ah ok, thanks for clarification about the docs CI

[axw]

@rodrigc sorry, one more hurdle: commits need to be signed. Would you please sign your commit and force push to update the branch? You can find out how to sign commits at https://docs.github.com/en/authentication/managing-commit-signature-verification/about-commit-signature-verification, if you're unfamiliar with that.

[rodrigc]

OK, I followed the steps to have a verified commit

[axw]

/run elasticsearch-ci/docs

[axw]

🎉 thank you @rodrigc!

[simitt]

Tested with BC 2: set policy to roll over at 9MB, ingested data and observed the rollover (not exactly at 9MB due to continous ingestion).