In Oracle Cloud Infrastructure (OCI), a Fault Domain is a grouping of hardware and infrastructure within a region that share a common power source and network switch. If a failure occurs within a fault domain, it could affect all the instances within that domain.
OCI allows you to spread your resources across multiple fault domains to minimize the impact of a potential failure. When you launch an instance, you can specify the fault domain in which it should be placed. You can also use the OCI API or command line interface to move an instance to a different fault domain if necessary.
It is also possible to create and use specific availability domains in oci, which are similar concepts to Fault domains but with an additional layer of isolation to minimize the impact of failure.
By spreading your resources across multiple fault domains and availability domains, you can ensure high availability and improve the resilience of your applications.