[ES|QL] METRICS command definition and validation

[vadimkibana]

Summary

Partially addresses #184498

The main contribution of this PR is the METRICS command validation cases:

See own-review below for more comments.

Checklist

Delete any items that are not applicable to this PR.

• Unit or functional tests were updated or added to match the most common scenarios

For maintainers

• This was checked for breaking API changes and was labeled appropriately

[vadimkibana]

I also noticed that METRICS kibana_sample_data_logstsdb avg(to_long(avg(2))) should error because of a nested aggregation function but doesn't

I've added validation to check for agg-in-agg function errors.

[vadimkibana]

Gave this a functionality a spin using the TSDB sample web logs. Seems like the validator isn't properly checking for the existence of fields in functions

The validator is actually checking for those fields in functions correctly, but those fields are missing from the reference map. The reference map contains only two fields:

To fetch the fields it executes this METRICS ESQL query with | LIMIT 0:

I guess, I need to change the way we retrieve the field list. It seems METRICS ... | LIMIT 0 has to be change to something else ...

---

Limit-0 query, expression data table and fields list for

metrics kibana_sample_data_logstsdb max(bytes) by host

---

Limit-0 query, expression data table and fields list for

FROM kibana_sample_data_logstsdb | stats max(bytes) by host

[vadimkibana]

@drewdaemon I've solved the missing field error by using FROM ... | LIMIT 0 instead of METRICS ... | LIMIT 0 to load the fields. bc03874

[drewdaemon]

Vadim do you want to do this in this PR or a follow-up? #186005

[drewdaemon]

@drewdaemon I've solved the missing field error by using FROM ... | LIMIT 0 instead of METRICS ... | LIMIT 0 to load the fields. bc03874

Just tried it out. Looks great!

[vadimkibana]

Vadim do you want to do this in this PR or a follow-up? #186005

@drewdaemon yes, I'll better to do it as a follow up, this is already too big.

[drewdaemon]

Suggested change

	const findNestedAggFunctionOfAggFunction = (agg: ESQLFunction): ESQLFunction | undefined => {
	const findNestedAggFunctionInAggFunction = (agg: ESQLFunction): ESQLFunction | undefined => {

[drewdaemon]

Approved with a couple comments. Thanks for all your work on this!

[kibana-ci]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 7715403

Failed CI Steps

• FTR Configs #85

Test Failures

• [job] [logs] FTR Configs #85 / console app console autocomplete feature Autocomplete behavior JSON autocompletion with placeholder fields

Metrics [docs]

Public APIs missing comments

Total count of every public API that lacks a comment. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats comments for more detailed information.

id	before	after	diff
@kbn/esql-ast	95	96	+1
@kbn/esql-validation-autocomplete	178	181	+3
total			+4

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
kbnUiSharedDeps-srcJs	3.2MB	3.2MB	+5.1KB

Unknown metric groups

API count

id	before	after	diff
@kbn/esql-ast	98	99	+1
@kbn/esql-validation-autocomplete	189	192	+3
total			+4

History

• 💔 Build #216272 failed fa198f3
• 💔 Build #216071 failed dc653d9
• 💔 Build #216070 failed cad62b1
• 💔 Build #215269 failed bbc273a
• 💔 Build #215178 failed 1b05483

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