As you may have been aware, we've been working on changing how MediaWiki
stores comments: instead of having them as fields in each revision
(rev_comment), log entry (log_comment), and so on, we're storing the text
in a central "comment" table and referring to them by ID from other tables
(log_comment_id and so on).
We've been writing to the new fields and tables since the end of February
2018, and have back-populated them for old revisions, log entries, and so
on. Now we're starting to look at stopping the writes to the old fields,
starting soon with testing wikis such as
test.wikipedia.org and also with
mediawiki.org. Other wikis will follow, likely in October after the DC
switch-back.
For the most part wiki users shouldn't notice any changes, however if you
notice something not displaying a comment or edit summary for new entries,
on these wikis let me know.
For users of the Data Services replicas, such as Toolforge, the views
currently simulate the old columns for you. However this may change in the
future. See
https://phabricator.wikimedia.org/T181650#4581384 for details.
MediaWiki developers should make sure code accessing comment fields makes
use of the CommentStore class that was introduced in MediaWiki 1.30.
You can watch
https://phabricator.wikimedia.org/T166733 (and any subtasks)
for more information on the deployment process.
--
Brad Jorsch (Anomie)
Senior Software Engineer
Wikimedia Foundation