debian-mirror-gitlab/doc/development/service_ping/metrics_dictionary.md
2022-07-29 14:03:07 +02:00

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Metrics Dictionary Guide

Service Ping metrics are defined in individual YAML files definitions from which the Metrics Dictionary is built. Currently, the metrics dictionary is built automatically once a day. When a change to a metric is made in a YAML file, you can see the change in the dictionary within 24 hours. This guide describes the dictionary and how it's implemented.

Metrics Definition and validation

We are using JSON Schema to validate the metrics definition.

This process is meant to ensure consistent and valid metrics defined for Service Ping. All metrics must:

  • Comply with the defined JSON schema.
  • Have a unique key_path .
  • Have an owner.

All metrics are stored in YAML files:

WARNING: Only metrics with a metric definition YAML and whose status is not removed are added to the Service Ping JSON payload.

Each metric is defined in a separate YAML file consisting of a number of fields:

Field Required Additional information
key_path yes JSON key path for the metric, location in Service Ping payload.
name no Metric name suggestion. Can replace the last part of key_path.
description yes
product_section yes The section.
product_stage yes The stage for the metric.
product_group yes The group that owns the metric.
product_category no The product category for the metric.
value_type yes string; one of string, number, boolean, object.
status yes string; status of the metric, may be set to active, removed, broken.
time_frame yes string; may be set to a value like 7d, 28d, all, none.
data_source yes string; may be set to a value like database, redis, redis_hll, prometheus, system.
data_category yes string; categories of the metric, may be set to operational, optional, subscription, standard. The default value is optional.
instrumentation_class yes string; the class that implements the metric.
distribution yes array; may be set to one of ce, ee or ee. The distribution where the tracked feature is available.
performance_indicator_type no array; may be set to one of gmau, smau, paid_gmau, or umau.
tier yes array; may contain one or a combination of free, premium or ultimate. The tier where the tracked feature is available. This should be verbose and contain all tiers where a metric is available.
milestone yes The milestone when the metric is introduced and when it's available to self-managed instances with the official GitLab release.
milestone_removed no The milestone when the metric is removed.
introduced_by_url no The URL to the merge request that introduced the metric to be available for self-managed instances.
removed_by_url no The URL to the merge request that removed the metric.
repair_issue_url no The URL of the issue that was created to repair a metric with a broken status.
options no object: options information needed to calculate the metric value.
skip_validation no This should not be set. Used for imported metrics until we review, update and make them valid.

Metric key_path

The key_path of the metric is the location in the JSON Service Ping payload.

The key_path could be composed from multiple parts separated by . and it must be unique.

We recommend to add the metric in one of the top-level keys:

  • settings: for settings related metrics.
  • counts_weekly: for counters that have data for the most recent 7 days.
  • counts_monthly: for counters that have data for the most recent 28 days.
  • counts: for counters that have data for all time.

NOTE: We can't control what the metric's key_path is, because some of them are generated dynamically in usage_data.rb. For example, see Redis HLL metrics.

Metric name

To improve metric discoverability by a wider audience, each metric with instrumentation added at an appointed key_path receives a name attribute filled with the name suggestion, corresponding to the metric data_source and instrumentation. Metric name suggestions can contain two types of elements:

  1. User input prompts: enclosed by angle brackets (< >), these pieces should be replaced or removed when you create a metrics YAML file.
  2. Fixed suggestion: plaintext parts generated according to well-defined algorithms. They are based on underlying instrumentation, and must not be changed.

For a metric name to be valid, it must not include any prompt, and fixed suggestions must not be changed.

Generate a metric name suggestion

The metric YAML generator can suggest a metric name for you. To generate a metric name suggestion, first instrument the metric at the provided key_path. Then, generate the metric's YAML definition and return to the instrumentation and update it.

  1. Add the metric instrumentation class to lib/gitlab/usage/metrics/instrumentations/.
  2. Add the metric logic in the instrumentation class.
  3. Run the metrics YAML generator.
  4. Use the metric name suggestion to select a suitable metric name.
  5. Update the metric's YAML definition with the correct key_path.

Metric statuses

Metric definitions can have one of the following statuses:

  • active: Metric is used and reports data.
  • broken: Metric reports broken data (for example, -1 fallback), or does not report data at all. A metric marked as broken must also have the repair_issue_url attribute.
  • removed: Metric was removed, but it may appear in Service Ping payloads sent from instances running on older versions of GitLab.

Metric value_type

Metric definitions can have one of the following values for value_type:

  • boolean
  • number
  • string
  • object: A metric with value_type: object must have value_json_schema with a link to the JSON schema for the object. In general, we avoid complex objects and prefer one of the boolean, number, or string value types. An example of a metric that uses value_type: object is topology (/config/metrics/settings/20210323120839_topology.yml), which has a related schema in /config/metrics/objects_schemas/topology_schema.json.

Metric time_frame

  • 7d: The metric data applies to the most recent 7-day interval. For example, the following metric counts the number of users that create epics over a 7-day interval: ee/config/metrics/counts_7d/20210305145820_g_product_planning_epic_created_weekly.yml.
  • 28d: The metric data applies to the most recent 28-day interval. For example, the following metric counts the number of unique users that create issues over a 28-day interval: config/metrics/counts_28d/20210216181139_issues.yml.
  • all: The metric data applies for the whole time the metric has been active (all-time interval). For example, the following metric counts all users that create issues: /config/metrics/counts_all/20210216181115_issues.yml.
  • none: The metric collects a type of data that's not tracked over time, such as settings and configuration information. Therefore, a time interval is not applicable. For example, uuid has no time interval applicable: config/metrics/license/20210201124933_uuid.yml.

Data category

We use the following categories to classify a metric:

  • operational: Required data for operational purposes.
  • optional: Default value for a metric. Data that is optional to collect. This can be enabled or disabled in the Admin Area.
  • subscription: Data related to licensing.
  • standard: Standard set of identifiers that are included when collecting data.

Metric name suggestion examples

Metric with data_source: database

For a metric instrumented with SQL:

SELECT COUNT(DISTINCT user_id) FROM clusters WHERE clusters.management_project_id IS NOT NULL
  • Suggested name: count_distinct_user_id_from_<adjective describing: '(clusters.management_project_id IS NOT NULL)'>_clusters
  • Prompt: <adjective describing: '(clusters.management_project_id IS NOT NULL)'> should be replaced with an adjective that best represents filter conditions, such as project_management
  • Final metric name: For example, count_distinct_user_id_from_project_management_clusters

For metric instrumented with SQL:

SELECT COUNT(DISTINCT clusters.user_id)
FROM clusters_applications_helm
INNER JOIN clusters ON clusters.id = clusters_applications_helm.cluster_id
WHERE clusters_applications_helm.status IN (3, 5)
  • Suggested name: count_distinct_user_id_from_<adjective describing: '(clusters_applications_helm.status IN (3, 5))'>_clusters_<with>_<adjective describing: '(clusters_applications_helm.status IN (3, 5))'>_clusters_applications_helm
  • Prompt: <adjective describing: '(clusters_applications_helm.status IN (3, 5))'> should be replaced with an adjective that best represents filter conditions
  • Final metric name: count_distinct_user_id_from_clusters_with_available_clusters_applications_helm

In the previous example, the prompt is irrelevant, and user can remove it. The second occurrence corresponds with the available scope defined in Clusters::Concerns::ApplicationStatus. It can be used as the right adjective to replace prompt.

The <with> represents a suggested conjunction for the suggested name of the joined relation. The person documenting the metric can use it by either:

  • Removing the surrounding <>.
  • Using a different conjunction, such as having or including.

Metric with data_source: redis or redis_hll

For metrics instrumented with a Redis-based counter, the suggested name includes only the single prompt to be replaced by the person working with metrics YAML.

  • Prompt: <please fill metric name, suggested format is: {subject}_{verb}{ing|ed}_{object} eg: users_creating_epics or merge_requests_viewed_in_single_file_mode>
  • Final metric name: We suggest the metric name should follow the format of {subject}_{verb}{ing|ed}_{object}, such as user_creating_epics, users_triggering_security_scans, or merge_requests_viewed_in_single_file_mode

Metric with data_source: prometheus or system

For metrics instrumented with Prometheus or coming from the operating system, the suggested name includes only the single prompt by person working with metrics YAML.

  • Prompt: <please fill metric name>
  • Final metric name: Due to the variety of cases that can apply to this kind of metric, no naming convention exists. Each person instrumenting a metric should use their best judgment to come up with a descriptive name.

Example YAML metric definition

The linked uuid YAML file includes an example metric definition, where the uuid metric is the GitLab instance unique identifier.

key_path: uuid
description: GitLab instance unique identifier
product_category: collection
product_section: growth
product_stage: growth
product_group: group::product intelligence
value_type: string
status: active
milestone: 9.1
instrumentation_class: UuidMetric
introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/1521
time_frame: none
data_source: database
distribution:
- ce
- ee
tier:
- free
- premium
- ultimate

Create a new metric definition

The GitLab codebase provides a dedicated generator to create new metric definitions.

For uniqueness, the generated files include a timestamp prefix in ISO 8601 format.

The generator takes a list of key paths and 3 options as arguments. It creates metric YAML definitions in the corresponding location:

  • --ee, --no-ee Indicates if metric is for EE.
  • --dir=DIR Indicates the metric directory. It must be one of: counts_7d, 7d, counts_28d, 28d, counts_all, all, settings, license.
  • --class_name=CLASS_NAME Indicates the instrumentation class. For example UsersCreatingIssuesMetric, UuidMetric

Single metric example

bundle exec rails generate gitlab:usage_metric_definition counts.issues --dir=7d --class_name=CountIssues
create  config/metrics/counts_7d/issues.yml

Multiple metrics example

bundle exec rails generate gitlab:usage_metric_definition counts.issues counts.users --dir=7d --class_name=CountUsersCreatingIssues
create  config/metrics/counts_7d/issues.yml
create  config/metrics/counts_7d/users.yml

NOTE: To create a metric definition used in EE, add the --ee flag.

bundle exec rails generate gitlab:usage_metric_definition counts.issues --ee --dir=7d --class_name=CountUsersCreatingIssues
create  ee/config/metrics/counts_7d/issues.yml

Metrics added dynamic to Service Ping payload

The Redis HLL metrics are added automatically to Service Ping payload.

A YAML metric definition is required for each metric. A dedicated generator is provided to create metric definitions for Redis HLL events.

The generator takes category and event arguments, as the root key is redis_hll_counters, and creates two metric definitions for weekly and monthly time frames:

bundle exec rails generate gitlab:usage_metric_definition:redis_hll issues count_users_closing_issues
create  config/metrics/counts_7d/count_users_closing_issues_weekly.yml
create  config/metrics/counts_28d/count_users_closing_issues_monthly.yml

To create a metric definition used in EE, add the --ee flag.

bundle exec rails generate gitlab:usage_metric_definition:redis_hll issues users_closing_issues --ee
create  config/metrics/counts_7d/i_closed_weekly.yml
create  config/metrics/counts_28d/i_closed_monthly.yml

Metrics Dictionary

Metrics Dictionary is a separate application.

All metrics available in Service Ping are in the Metrics Dictionary.

Copy query to clipboard

To check if a metric has data in Sisense, use the copy query to clipboard feature. This copies a query that's ready to use in Sisense. The query gets the last five service ping data for GitLab.com for a given metric. For information about how to check if a Service Ping metric has data in Sisense, see this demo.