Simplify metric definition:

  - Remove name attribute, currenlty doesn't add any
  value to metric definition
  - Use key_path for JSON key path,
  location in Usage Ping payload
  - Update docs

config/metrics/counts_28d/deployments.yml

-name: deployments
+key_path: counts_monthy.deployments
 description: Total deployments count for recent 28 days
 value_type: integer
 stage: release
 status: data_available
-default_generation: generation_1
-full_path:
-  generation_1: counts_monthy.deployments
 milestone: 13.2
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/35493
 group: 'group::ops release'

config/metrics/counts_7d/g_project_management_issue_title_changed_weekly.yml

-name: g_project_management_issue_title_changed_weekly
+key_path: redis_hll_counters.issues_edit.g_project_management_issue_title_changed_weekly
 description: Distinct users count that changed issue title in a group for last recent week
 value_type: integer
 product_category: issue_tracking
 stage: plan
 status: data_available
-default_generation: generation_1
-full_path:
-  generation_1: redis_hll_counters.issues_edit.g_project_management_issue_title_changed_weekly
 milestone: 13.6
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/issues/229918
 group: 'group::project management'

config/metrics/counts_all/deployments.yml

-name: deployments
+key_path: counts.deployments
 description: Total deployments count
 value_type: integer
 stage: release
 status: data_available
-default_generation: generation_1
-full_path:
-  generation_1: counts.deployments
 milestone: 8.12
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/735
 group: 'group::ops release'

config/metrics/license/recorded_at.yml

-name: recorded_at
+key_path: recorded_at
 description: When the Usage Ping computation was started
 value_type: string
 product_category: collection
 stage: growth
 status: data_available
-default_generation: generation_1
-full_path:
-  generation_1: recorded_at
 milestone: 8.10
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/557
 group: group::product analytics

config/metrics/license/uuid.yml

-name: uuid
+key_path: uuid
 description: GitLab instance unique identifier
 value_type: string
 product_category: collection
 stage: growth
 status: data_available
-default_generation: generation_1
-full_path:
-  generation_1: uuid
-  generation_2: license.uuid
 milestone: 9.1
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/1521
 group: group::product analytics

config/metrics/schema.json

 {
   "type": "object",
-  "required": ["name", "description", "value_type", "status", "default_generation", "full_path", "group", "time_frame", "data_source", "distribution", "tier"],
+  "required": ["key_path", "description", "value_type", "status", "group", "time_frame", "data_source", "distribution", "tier"],
   "properties": {
-    "name": {
+    "key_path": {
       "type": "string"
     },
     "description": {
@@ -22,12 +22,6 @@
       "type": ["string"],
       "enum": ["data_available", "planned", "in_progress", "implmented"]
     },
-    "default_generation": {
-      "type": "string"
-    },
-    "full_path": {
-      "type": "object"
-    },
     "milestone": {
       "type": ["number", "null"]
     },

config/metrics/settings/database_adapter.yml

-name: adapter
+key_path: database.adapter
 description: This metric only returns a value of PostgreSQL in supported versions of GitLab. It could be removed from the usage ping. Historically MySQL was also supported.
 value_type: string
 product_category: collection
 stage: growth
 status: data_available
-default_generation: generation_1
-full_path:
-  generation_1: database.adapter
 group: group::enablement distribution
 time_frame: none
 data_source: database

doc/development/usage_ping/metrics_dictionary.md

@@ -15,7 +15,7 @@ We are using [JSON Schema](https://gitlab.com/gitlab-org/gitlab/-/blob/master/co
 This process is meant to ensure consistent and valid metrics defined for Usage Ping. All metrics *must*:
 
 - Comply with the definied [JSON schema](https://gitlab.com/gitlab-org/gitlab/-/blob/master/config/metrics/schema.json).
-- Have a unique `full_path` .
+- Have a unique `key_path` .
 - Have an owner.
 
 All metrics are stored in YAML files:
@@ -26,12 +26,10 @@ Each metric is definied in a separate YAML file consisting of a number of fields
 
 | Field               | Required | Additional information                                         |
 |---------------------|----------|----------------------------------------------------------------|
-| `name`              | yes      |                                                                |
+| `key_path`          | yes      | JSON key path for the metric, location in Usage Ping payload.  |
 | `description`       | yes      |                                                                |
 | `value_type`        | yes      |                                                                |
 | `status`            | yes      |                                                                |
-| `default_generation`| yes      | Default generation path of the metric. One full_path value. (1) |
-| `full_path`         | yes      | Full path of the metric for one or multiple generations. Path of the metric in Usage Ping payload. (1) |
 | `group`             | yes      | The [group](https://about.gitlab.com/handbook/product/categories/#devops-stages) that owns the metric. |
 | `time_frame`        | yes      | `string`; may be set to a value like "7d"                             |
 | `data_source`       | yes      | `string`: may be set to a value like `database` or `redis_hll`.       |
@@ -43,9 +41,6 @@ Each metric is definied in a separate YAML file consisting of a number of fields
 | `milestone_removed` | no       | The milestone when the metric is removed. |
 | `introduced_by_url` | no       | The URL to the Merge Request that introduced the metric. |
 
-1. The default generation path is the location of the metric in the Usage Ping payload.
-   The `full_path` is the list locations for multiple Usage Ping generaations.
-
 ### Example metric definition
 
 The linked [`uuid`](https://gitlab.com/gitlab-org/gitlab/-/blob/master/config/metrics/license/uuid.yml)
@@ -53,16 +48,12 @@ YAML file includes an example metric definition, where the `uuid` metric is the
 instance unique identifier.
 
 ```yaml
-name: uuid
+key_path: uuid
 description: GitLab instance unique identifier
 value_type: string
 product_category: collection
 stage: growth
 status: data_available
-default_generation: generation_1
-full_path:
-  generation_1: uuid
-  generation_2: license.uuid
 milestone: 9.1
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/1521
 group: group::product intelligence

ee/config/metrics/counts_all/geo_nodes.yml

-name: geo_nodes
+key_path: counts.geo_nodes
 description: Total number of sites in a Geo deployment
 value_type: integer
 product_category: disaster_recovery
 stage: enablement
 status: data_available
-default_generation: generation_1
-full_path:
-  generation_1: counts.geo_nodes
 milestone: 11.2
 group: 'group::geo'
 time_frame: all

lib/gitlab/usage/metric.rb

@@ -7,16 +7,16 @@ module Gitlab
 
       InvalidMetricError = Class.new(RuntimeError)
 
-      attr_accessor :default_generation_path, :value
+      attr_accessor :key_path, :value
 
-      validates :default_generation_path, presence: true
+      validates :key_path, presence: true
 
       def definition
-        self.class.definitions[default_generation_path]
+        self.class.definitions[key_path]
       end
 
-      def unflatten_default_path
-        unflatten(default_generation_path.split('.'), value)
+      def unflatten_key_path
+        unflatten(key_path.split('.'), value)
       end
 
       class << self

lib/gitlab/usage/metric_definition.rb

@@ -13,9 +13,8 @@ module Gitlab
         @attributes = opts
       end
 
-      # The key is defined by default_generation and full_path
       def key
-        full_path[default_generation.to_sym]
+        key_path
       end
 
       def to_h

spec/lib/gitlab/usage/metric_definition_spec.rb

@@ -5,17 +5,13 @@ require 'spec_helper'
 RSpec.describe Gitlab::Usage::MetricDefinition do
   let(:attributes) do
     {
-      name: 'uuid',
       description: 'GitLab instance unique identifier',
       value_type: 'string',
       product_category: 'collection',
       stage: 'growth',
       status: 'data_available',
       default_generation: 'generation_1',
-      full_path: {
-        generation_1: 'uuid',
-        generation_2: 'license.uuid'
-      },
+      key_path: 'uuid',
       group: 'group::product analytics',
       time_frame: 'none',
       data_source: 'database',
@@ -44,12 +40,11 @@ RSpec.describe Gitlab::Usage::MetricDefinition do
     using RSpec::Parameterized::TableSyntax
 
     where(:attribute, :value) do
-      :name               | nil
       :description        | nil
       :value_type         | nil
       :value_type         | 'test'
       :status             | nil
-      :default_generation | nil
+      :key_path           | nil
       :group              | nil
       :time_frame         | nil
       :time_frame         | '29d'

spec/lib/gitlab/usage/metric_spec.rb

@@ -4,15 +4,15 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Usage::Metric do
   describe '#definition' do
-    it 'returns generation_1 metric definiton' do
-      expect(described_class.new(default_generation_path: 'uuid').definition).to be_an(Gitlab::Usage::MetricDefinition)
+    it 'returns key_path metric definiton' do
+      expect(described_class.new(key_path: 'uuid').definition).to be_an(Gitlab::Usage::MetricDefinition)
     end
   end
 
   describe '#unflatten_default_path' do
     using RSpec::Parameterized::TableSyntax
 
-    where(:default_generation_path, :value, :expected_hash) do
+    where(:key_path, :value, :expected_hash) do
       'uuid'                                     | nil    | { uuid: nil }
       'uuid'                                     | '1111' | { uuid: '1111' }
       'counts.issues'                            | nil    | { counts: { issues: nil } }
@@ -21,7 +21,7 @@ RSpec.describe Gitlab::Usage::Metric do
     end
 
     with_them do
-      subject { described_class.new(default_generation_path: default_generation_path, value: value).unflatten_default_path }
+      subject { described_class.new(key_path: key_path, value: value).unflatten_key_path }
 
       it { is_expected.to eq(expected_hash) }
     end