An hypervisor needs to be rebooted. Customers that are impacted will shortly receive an email and add-ons that can be migrated will be migrated before the reboot. Estimated downtime is about 15 minutes.
Add-ons will start being migrated at 20:30 UTC+2. Hypervisor will be rebooted at 21:30 UTC+2
EDIT 20:36 UTC+2: Maintenance is starting. Applications are getting redeployed and add-ons are starting their migrations
EDIT 21:30 UTC+2: Add-ons that could be migrated have been migrated, applications have been redeployed. Server will now reboot
EDIT 22:00 UTC+2: Server has finished its reboot, add-ons that weren't migrated should have been reachable since 21:45 UTC+2. The maintenance is over.