Problem/Motivation
update.settings.yml
says:
check:
disabled_extensions: false
interval_days: 1
If this value is set to 0 or lower, the logic in update_cron()
pulls down update data from d.o on every cron run, for every multisite that has update module enabled.
This is a costly for d.o which has to handle these requests for all sites everywhere.
Proposed resolution
Add a usefulness check on the days-before-next-check value so that it never falls below one.
Allow arbitrary days-until-check settings to encourage even longer intervals, which means less bandwidth cost for the Drupal Association.
Document or somehow encourage users to disable update module on redundant sites, such as multisite.
Remaining tasks
There will likely be a follow-up where the update API is redesigned to be more efficient and scalable.
User interface changes
The settings form for the days-until-check setting will change from a 1 or 7 day dropdown to a numeric setting if the user has changed the value in some other way.
The user can issue a Drush command such as drush cset update.settings check.interval_days 23
and this value will then be reflected in the UI. If they change it back to 1 or 7, the dropdown will return.
API changes
Data model changes