Update: downtime window has been shortened from 2 hours to 30 minutes.
Drupal.org will be going down for up to 30 minutes starting Tuesday, April 29th, 17:00 PDT (April 30th, 0:00 UTC).
This maintenance window will be used for an issue queue update, which will need to alter a large table,. Logging into sub-sites (api.drupal.org, groups.drupal.org, etc) will be disabled; they will otherwise remain available.
Please follow the @drupal_infra Twitter account for updates during the downtime.
Thanks for your patience!