To provide usage tracking off tabular data and chart definitions used in the Chart extension (T374746), JsonConfig has been extended (T374747) with an optional cross-wiki usage tracking table set: globaljsonlinks, globaljsonlinks_target, and globaljsonlinks_wiki.

For the production environment these will live on x1 cluster.

(A test deployment [T378127] occurred to avoid polluting tables with pre-production data, and has a temporary installation of these tables on testcommonswiki)

• Should this table be replicated to wiki replicas (does it not contain private data)?
  • ok to replicate (public derived data)
• Will you be doing cross-joins with the wiki metadata?
  • no cross-joins, is meant to live standalone. references page_namespace/page_title indirectly on each side.
• Size of the table (number of rows expected).
  • 1 row in globaljsonlinks per chart invocation, this is expected to be a few tens of thousands of rows
  • smaller number of rows in globaljsonlinks_wiki and globaljsonlinks_target which consolidate strings for source wikis (a few hundred) and target data page references (smaller than the total number of invocations)
• Expected growth per year (number of rows).
  • relatively small in future, though it will grow more intensely at first as we migrate old Graphs invocations and create new Charts invocations. on the order of thousands of rows/year expected.
• Expected amount of queries, both writes and reads (per minute, per hour...per day, any of those are ok).
  • makes at least one read query per LinksUpdate in job queue
  • makes inserts/deletes during LinksUpdate in job queue
  • updating a data page on Commons will trigger a read to distribute cache invalidation jobs
• Examples of queries that will be using the table.
  • Mostly SELECTs joining the three globaljsonlinks tables in-place and issuance of fresh INSERTs when recording new links; these either return all matching links for a given outgoing source page or given incoming target page, or return id numbers of existing records.
  • No joins against remote tables, only between the tree globaljsonlinks* tables.
• The release plan for the feature (are there specific wikis you'd like to test first etc).
  • we are running this setup on testcommonswiki as a temporary master for a test rollout
  • This production version will live on x1 in a standalone database to serve as the store for changes made on commons. Testing of the globallinks functionality with commons will occur on Test2 wiki

• Create the tables to testcommonswiki on s4 on a temporary basis, with intent to remove them after tearing down the test deployment -Table schema json in Extension:JsonConfig
• Deply config patch needed to point testcommonswiki & testwiki's virtual-globaljsonlinks domain at testcommonswiki, and enable $wgTrackGlobalJsonLinks for those two wikis to start populating links - https://gerrit.wikimedia.org/r/c/operations/mediawiki-config/+/1087975/