# 0020: Version Type Field Migration
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- Stage: **X (abandoned)** <!-- Update to reflect target stage. See https://elastic.github.io/ecs/stages.html -->
- Date: **2021-07-20** <!-- The ECS team sets this date at merge time. This is the date of the latest stage advancement. -->

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## Abandoned

As the time this proposal was marked `abandoned`, adopting `version` is not a priority for the ECS team or other ECS stakeholders. The team may revisit reviewing how `version` could be beneficial later on.

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Elasticsearch 7.10 introduced a new field data type specialized in handling software version values: `version`. The `version` type supports specialized precedence rules based on the rules outlined in [Semantic Versioning](semver.org) (semver). A `range` query against a `version` field for values between `1.0.0` and `1.5.0` will include `1.2.3` but not `1.11.2`. This differs from `keyword` fields where the `range` ordering is alphabetical.

Examples:

* Return documents with `.version` greater-than or equal to `1.1.0` and less-than `2.0.0`
* Query across multiple versions without the need to know in advance ever possible versions in the index (e.g. `ecs.version:(1.3.0 OR 1.4.0 OR 1.5.0`)
* Return all documents where minor version is 3 (`x.3.y`) or the major version is considered unstable (`0.x.y`).

The purpose of this proposal is to identify which fields may be good candidates for adopting the `version` data type and design considerations for that migration.

## Fields

* `agent.version`
* `ecs.version`
* `os.version`
* `package.version`
* `rule.version`
* `service.version`

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## Usage

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## Source data

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## Scope of impact

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### Mapping conflicts

Changing the field type will result in a mapping conflict across indices mapping version fields using `type: keyword` and indices mapping version fields as `type: version`.

## Concerns

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### Version fields containing non-semantic version values

Version string values that are not valid under the semver rules will still be indexed and retrieved as exact matches but will only appear _after_ any valid semver value with regular alphabetical ordering.

Fields that expect version values but often contains values that do _not_ align with semver rules are probably best to remain using `keyword`. The [list](#Fields) of proposed fields will be assessed in a later stage to determine if each field's expected values make it a good candidate for `version`.


### Kibana support

Support in Kibana for the `version` data for index patterns, aggregations, and Lens is still [in-progress](https://github.com/elastic/kibana/issues/93248).

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## People

The following are the people that consulted on the contents of this RFC.

* @ebeahan | author, sponsor

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## References

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* https://github.com/elastic/ecs/issues/887
* https://github.com/elastic/ecs/issues/842
* https://www.elastic.co/guide/en/elasticsearch/reference/current/version.html
* https://github.com/elastic/kibana/issues/93248

### RFC Pull Requests

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* Stage 0: https://github.com/elastic/ecs/pull/1309
* Stage X: https://github.com/elastic/ecs/pull/1451

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