Update ilm-rollover.asciidoc

[berto-lstc]

With max_primary_shard_size: 50gb, the size "at most 50gb" not "at least" as indicated in the docs.

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[elasticsearchmachine]

@berto-lstc please enable the option "Allow edits and access to secrets by maintainers" on your PR. For more information, see the documentation.

[joegallo]

Hmmm... I'm not sure I agree with this change in wording -- can you elaborate?

[berto-lstc]

sure @joegallo , max_primary_shard_size setting is the maximum size the primary shard can reach, in the documentation it says "at least" which I understand as the minimum size.
In the original document:
"This example rolls the index over when the primary shard size is at least 50gb"
The configuration is as follows:

"rollover" : {
            "max_primary_shard_size": "50gb",
            "max_age": "30d",
            "min_primary_shard_size": "1gb"
          }

The primary shard size is at least 1gb, thus >1GB, and the primary shard size max is 50GB., then primary_shard_size will be 50gb at most, not "at least" as it's written now.

Perhaps I'm missing something.

[elasticsearchmachine]

Pinging @elastic/es-docs (Team:Docs)

[joegallo]

No, I still think "at least" is the correct wording.

The rollover code will not roll over the index until the primary size is equal to or greater than the configured size.

[joegallo]

I'm marking a red X on this because I don't want somebody else to come along and add a green check without first convincing me.

[joegallo]

All min_ conditions must be satisfied for rollover to occur. At least one max_ condition must be satisfied for rollover to occur.

The policy can be restated like this:

A.) The index will roll over as long as it has a primary shard that is AT LEAST 50gb, AND it has a primary shard that is AT LEAST 1gb (yes, this is duplicated, bear with me).

OR

B.) The index will roll over as long as it is AT LEAST 30 days old, AND it has a primary shard that is AT LEAST 1gb.

Let's apply a round of simplification, and remove the duplicated size requirements in the first half, since the only way a primary shard will be at least 50gb is if it is also at least 1gb:

A.) The index will roll over as long as it has a primary shard that is AT LEAST 50gb.

OR

B.) The index will roll over as long as it is AT LEAST 30 days old, AND it has a primary shard that is AT LEAST 1gb.

Or, dropping the extra formatting, we have the wording from the doc in question itself, which is:

This example rolls the index over when the primary shard size is at least 50gb,
or when the index is at least 30 days old, but only as long as a primary shard is at least 1gb.