I got an email notification that there was some downtime today between 4:35am ET and 6:11am ET.
I looked at the error log to see what could be a cause and saw these entries:
[Tue Jul 09 04:35:01 2024] [notice] [pid 108823] sapi_apache2.c(349): [client 116.202.254.214:54230] WordPress database error WSREP has not yet prepared node for application use for query SELECT * FROM `wp_cavalcade_jobs` WHERE site = 1120 AND hook = 'jetpack_v2_heartbeat' AND args = 'a:0:{}' AND status IN('waiting','running') ORDER BY nextrun ASC LIMIT 1 made by require('wp-blog-header.php'), require_once('wp-load.php'), require_once('wp-config.php'), require_once('wp-settings.php'), do_action('plugins_loaded'), WP_Hook->do_action, WP_Hook->apply_filters, Jetpack->configure, Jetpack_Heartbeat::init, Automattic\\Jetpack\\Heartbeat::init, Automattic\\Jetpack\\Heartbeat->__construct, wp_next_scheduled, wp_get_scheduled_event, apply_filters('pre_get_scheduled_event'), WP_Hook->apply_filters, HM\\Cavalcade\\Plugin\\Connector\\pre_get_scheduled_event, HM\\Cavalcade\\Plugin\\Job::get_jobs_by_query
[Tue Jul 09 04:35:02 2024] [notice] [pid 109152] sapi_apache2.c(349): [client 84.51.29.236:4803] WordPress database error WSREP has not yet prepared node for application use for query SELECT display_meta, notifications FROM wp_1859_gf_form_meta WHERE form_id=1 made by require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), include('/themes/twentyfourteen/single.php'), get_sidebar, locate_template, load_template, require_once('/themes/twentyfourteen/sidebar.php'), dynamic_sidebar, WP_Widget->display_callback, GFWidget->widget, GFFormsModel::get_form_meta
I looked up this error -- https://galeracluster.com/library/documentation/crash-recovery.html -- and it looks like one of the database cluster nodes went down, which might have triggered a database restart from Lihua's scripts. I haven't contacted IT about this yet.
Sorry for the double-post for those that already received it. I previously posted this message in the wrong ticket (#18841).