For highest level of resilience you can deploy the application between regions and distribute on availability domain and fault domains.

https://www.oracle.com/cloud/iaas/faq.html

Oracle Cloud Infrastructure is hosted in regions and availability domains. A region is a localized geographic area, and an availability domain is one or more data centers located within a region. A region is composed of one or more availability domains.

Regions are independent of other regions and can be separated by vast distances---across countries or even continents.

Availability domains are isolated from each other, fault tolerant, and very unlikely to fail simultaneously. Because availability domains do not share infrastructure such as power or cooling, or the internal availability domain network, a failure at one availability domain within a region is unlikely to impact the availability of the others within the same region.

Fault domain is a grouping of hardware and infrastructure within an availability domain. Each availability domain contains three fault domains. Fault domains provide anti-affinity: they let you distribute your instances so that the instances are not on the same physical hardware within a single availability domain. A hardware failure or Compute hardware maintenance event that affects one fault domain does not affect instances in other fault domains. In addition, the physical hardware in a fault domain has independent and redundant power supplies, which prevents a failure in the power supply hardware within one fault domain from affecting other fault domains.

https://docs.cloud.oracle.com/en-us/iaas/Content/General/Concepts/regions.htm

Oracle Functions is a fully managed, multi-tenant, highly scalable, on-demand, Functions-as-a-Service platform. It is built on enterprise-grade Oracle Cloud Infrastructure and powered by the Fn Project open source engine. Use Oracle Functions (sometimes abbreviated to just Functions) when you want to focus on writing code to meet business needs.

Theserverlessandelasticarchitecture of Oracle Functions means there's no infrastructure administration or software administration for you to perform. You don't provision or maintain compute instances, and operating system software patches and upgrades are applied automatically. Oracle Functions simply ensures your app is highly-available, scalable, secure, and monitored. With Oracle Functions, you can write code in Java, Python, Node, Go, and Ruby (and for advanced use cases, bring your own Dockerfile, and Graal VM). You can then deploy your code, call it directly or trigger it in response to events, and get billed only for the resources consumed during the execution.

You can create and manage resources in the following ways:

Oracle Cloud Infrastructure Console The Console is an intuitive, graphical interface that lets you create and manage your instances, cloud networks, and storage volumes, as well as your users and permissions. SeeUsing the Console.

Oracle Cloud Infrastructure APIs The Oracle Cloud Infrastructure APIs are typical REST APIs that use HTTPS requests and responses. SeeAPI Requests.

SDKs Several Software Development Kits are available for easy integration with the Oracle Cloud Infrastructure APIs, including SDKs for Java, Ruby, and Python. For more information, seeDeveloper Resources.

Command Line Interface (CLI) You can use a command line interface with some services. For more information, seeDeveloper Resources.

Terraform Oracle supports Terraform. Terraform is 'infrastructure-as-code' software that allows you to define your infrastructure resources in files that you can persist, version, and share. For more information, seeGetting Started with the Terraform Provider.

Ansible Oracle supports the use of Ansible for cloud infrastructure provisioning, orchestration, and configuration management. Ansible allows you to automate configuring and provisioning your cloud infrastructure, deploying and updating software assets, and orchestrating your complex operational processes. For more information, seeGetting Started with Ansible for Oracle Cloud Infrastructure.

Resource Manager Resource Manager is an Oracle Cloud Infrastructure service that allows you to automate the process of provisioning your Oracle Cloud Infrastructure resources. It helps you install, configure, and manage resources using the 'infrastructure-as-code' model. For more information, seeOverview of Resource Manager.

https://docs.cloud.oracle.com/en-us/iaas/pdf/gsg/OCI_Getting_Started.pdf

Open a support service request with MOS option is available to paid accounts. Customers using only Always Free resources are not eligible for Oracle Support. Limited support is available to Free Tier accounts with Free Trial credits. After you use all of your credits or after your trial period ends (whichever comes first), you must upgrade to a paid account to access Oracle Support. If you choose not to upgrade and continue to use Always Free Services, you will not be eligible to raise a service request in My Oracle Support.

In addition to support for technical issues, useMy Oracle Supportif you need to:

* Reset the password or unlock the account for the tenancy administrator

* Add or change a tenancy administrator

* Request aservice limitincrease

https://docs.cloud.oracle.com/en-us/iaas/Content/GSG/Tasks/contactingsupport.htm