Single write region
All clients will automatically redirect reads to other regions. No read or write availability loss for all configurations, except 2 regions with strong consistency which loses write availability until the service is restored or, if service-managed failover is enabled, the region is marked as failed and a failover occurs.
No data loss.
Read region outage
What to do
During the outage, ensure that there are enough provisioned RUs in the remaining regions to support read traffic.When the outage is over, re-adjust provisioned RUs as appropriate.