How can you ensure high availability of applications hosted in OCI?

Utilizing multiple availability domains is a crucial strategy for ensuring high availability of applications hosted in Oracle Cloud Infrastructure (OCI). Availability domains are isolated locations within a region that provide redundant and independent power, cooling, and network connectivity. By deploying applications across multiple availability domains, you can protect against outages that may affect a single domain.

In the event of a failure in one availability domain, the applications can continue to operate in the other domains, thus minimizing downtime and maintaining service continuity. This setup allows for a more resilient architecture where resources can be effectively managed and scaled, ensuring that applications remain accessible to users even during incidents that impact one part of the infrastructure.

Other options do not support the same level of resilience. For instance, relying on a single compute instance does not offer redundancy and presents a single point of failure. Limiting the number of resources reduces the capacity and resilience necessary for high availability, and deploying in only one region can be risky since it may expose the application to regional outages without any failover options. Therefore, leveraging multiple availability domains is an essential practice for achieving high availability in OCI.