[Rest Api Compatibility] _time and _term sort orders

[pgomulka]

Previously removed in #39450, deprecated in es6 but not removed in es 7.
defaults to _key behaviour

relates #51816

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[elasticmachine]

Pinging @elastic/es-analytics-geo (Team:Analytics)

[pgomulka]

removal of _time and _term was marked as discuss for rest api compatibility. Hence the team-discuss label
@elastic/es-analytics-geo let me know if we plan to merge the rest api compatible change or backport the removal to 7.x
I would prefer to merge this PR to master and remove the support to _key and _time in master only. It would be easier for users.

[nik9000]

I would prefer to merge this PR to master and remove the support to _key and _time in master only. It would be easier for users.

Do you mean you'd prefer to just merge this to master, no backports? In other words, this removal gets a super long deprecation cycle? That's fine with me. I don't think it's hurting anyone.

[pgomulka]

Do you mean you'd prefer to just merge this to master, no backports? In other words, this removal gets a super long deprecation cycle?

yes, there is a chance to make it easier for users to upgrade, so why not :)
unless there are other reasons to remove it in 7 which I am not aware of.

[nik9000]

Yeah - I'm 👍 to do it the way you've proposed. Do we have a way of knowing when to drop support for it? I guess at some point we'll remove the constant you are comparing to and just zap all of the statements it guards.

[pgomulka]

when we bump RestApiVersion.minimumSupported to 8 (current version would be 9) then the code https://github.com/elastic/elasticsearch/pull/74919/files#diff-ab996c9a4e31c3c2e1c2df8238d258c0217fecc258066faa02e0c7a5701255afR578 will become dead.
We will likely follow up after a version bump with a cleanup and remove all usages of RestApiVersion.V_7

[nik9000]

We will likely follow up after a version bump with a cleanup and remove all usages of RestApiVersion.V_7

That's awesome! I that we can remove the dead code in as many changes as we need after dropping the support.

[elasticmachine]

Pinging @elastic/es-core-infra (Team:Core/Infra)