Description

Metrics Platform provides the least-effort approach to instrument WikiLambda for event logging, and appears to meet our needs (subject to further analysis). Once we've defined one or more streams, it's very easy to start creating instruments in JavaScript and/or PHP code.

No schema creation is needed; MP relies on a predefined "monoschema".

The essential requirement for defining an MP stream is to determine which of the predefined "contextual values" should be added to the stream's events, by MP. (Note: In addition to these contextual values, event-specific "custom values" can be specified by each instrument. These custom values are not mentioned in the stream's definition.)

If our initial logging is focused on function editing steps, some candidates for contextual values (i.e., keys for the values) would be: agent.client_platform_family (indicates mobile versus desktop device), page.id, page.title, page.revision_id, performer.is_logged_in, performer.id, performer.name, performer.session_id, performer.language, performer.language_variant, performer.edit_count. Note: if a value for any of these keys isn't available when a particular event is created, MP handles it gracefully (e.g., by inserting a null value).

Once these contextual values have been determined, and a stream name chosen, the stream can be declared in ext-EventStreamConfig.php, for production and beta, or in InitialiseSettings-labs.php, for beta only.

Relevant documentation is at Metrics_Platform/Creating_a_Stream_Configuration and related pages. Example MP stream definitions can be found in ext-EventStreamConfig.php, by searching for metrics_platform_client.

Desired behavior/Acceptance criteria

• Once instrument(s) for the stream have been created, their behavior should be consistent with what's described at Event_Platform/Instrumentation_How_To#Viewing_and_querying_events

Completion checklist

• Before closing this task, review one by one the checklist available here: https://www.mediawiki.org/wiki/Abstract_Wikipedia_team/Definition_of_Done#Front-end_Task/Bug_Completion_Checklist