OCI Logging service is a highly scalable and fully managed service that allows you to access logs from OCI resources. OCI Logging allows three kinds of logs: Audit, service, and custom logs. You can find more details for each of these logs in the documentation3 OCI Logging service is a centralized single pane of glass for all logs in a tenancy. You can view and search logs on the Logging Search page. When searching logs, you can correlate across many logs simultaneously. For example, you can view results from multiple logs, multiple log groups, or even an entire compartment with one query3 OCI Logging service can index, enrich, and aggregate log data from application. Custom logs are logs that contain diagnostic information from custom applications, other cloud providers, or an on-premises environment. Custom logs can be ingested through the API, or by configuring the Unified Monitoring Agent. You can configure an OCI compute instance/resource to directly upload Custom Logs through the Unified Monitoring Agent. Custom logs are supported in both a virtual machine and bare metal scenario3 OCI Logging service can analyze critical diagnostic information that describes how resources are performing and being accessed. These logs include audit logs related to events emitted by the OCI Audit service, such as API calls or console actions performed by users or services in your tenancy; service logs emitted by OCI native services, such as API Gateway, Events, Functions, Load Balancer, Object Storage, and VCN Flow Logs; and custom logs from your own applications or sources3

A single registry can contain both private and public Docker repositories in OCIR. A private repository requires authentication to pull images, while a public repository allows anyone with internet access and the appropriate URL to pull images. You can create and manage both types of repositories using the OCI Console or the Docker CLI3.

Users are not a component of the OCI Identity domains, but rather a resource within an identity domain. An identity domain is a container for managing users and roles, federating and provisioning of users, secure application integration through Oracle Single Sign-On (SSO) configuration, and SAML/OAuth based Identity Provider administration1.

Compartment and Cost-tracking tag are two valid targets for setting up OCI budgets. Budgets are set on cost-tracking tags or compartments (including the root compartment) to track all spending in that cost-tracking tag or for that compartment and its children2. You can create alerts on your budget to receive email notifications based on actual or forecasted spending thresholds2.

The Oracle Cloud Infrastructure Domain Name System (DNS) service lets you create and manage your DNS zones. You can create zones, add records to zones, and allow Oracle Cloud Infrastructure’s edge network to handle your domain’s DNS queries.

The primary purpose of a network security group (NSG) in the Oracle Cloud Infrastructure Networking service is to control traffic flow between specific resources within a VCN. An NSG is a set of virtual firewall rules that can be applied to one or more resources, such as instances, load balancers, or database nodes. NSGs allow users to define granular security policies for different types of resources within a VCN.

To design a high availability architecture, three key elements should be considered- redundancy, monitoring, and failover:
1) Redundancy means that multiple components can perform the same task. The problem of a single point of failure is eliminated because redundant components can take over a task performed by a component that has failed.
2) Monitoring means checking whether or not a component is working properly.
3) Failover is the process by which a secondary component becomes primary when the primary component fails.
The best practices introduced here focus on these three key elements. Although high availability can be achieved at many different levels, including the application level and the cloud infrastructure level, here we will focus on the cloud infrastructure level.
An Oracle Cloud Infrastructure region is a localized geographic area composed of one or more availability domains, each composed of three fault domains. High availability is ensured by a redundancy of fault domains within the availability domains.
An availability domain is one or more data centers located within a region. Availability domains are isolated from each other, fault tolerant, and unlikely to fail simultaneously. Because availability domains do not share physical infrastructure, such as power or cooling, or the internal availability domain network, a failure that impacts one availability domain is unlikely to impact the availability of others.
A fault domain is a grouping of hardware and infrastructure within an availability domain. Each availability domain contains three fault domains. Fault domains let you distribute your instances so that they are not on the same physical hardware within a single availability domain. As a result, an unexpected hardware failure or a Compute hardware maintenance that affects one fault domain does not affect instances in other fault domains. You can optionally specify the fault domain for a new instance at launch time, or you can let the system select one for you.
All the availability domains in a region are connected to each other by a low-latency, high bandwidth network. This predictable, encrypted interconnection between availability domains provides the building blocks for both high availability and disaster recovery.

The Accelerated Data Science (ADS) SDK is an Oracle-developed Python library that makes common data science tasks faster, easier, and less error prone. The ADS SDK provides tools for data ingestion, exploration, transformation, visualization, modeling, evaluation, interpretation, and deployment. The ADS SDK also integrates with other popular Python libraries such as pandas, scikit-learn, TensorFlow, PyTorch, etc.
The ADS SDK is included as part of the Data Science service at no additional cost. The Data Science service is a fully managed platform that enables data scientists to build, train, deploy, and manage machine learning models on OCI. The Data Science service provides access to notebook sessions that come pre-installed with the ADS SDK and other essential Python packages for data science workflows.

An instance configuration is the term used to describe the combination of an instance’s shape, base image, and metadata in the Oracle Cloud Infrastructure Compute service. An instance configuration defines the hardware and software specifications for launching an instance.

https://docs.oracle.com/en/cloud/paas/atp-cloud/index.html

A 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.
To control the placement of your compute instances, bare metal DB system instances, or virtual machine DB system instances, you can optionally specify the fault domain for a new instance or instance pool at launch time. If you don’t specify the fault domain, the system selects one for you. Oracle Cloud Infrastructure makes a best-effort anti-affinity placement across different fault domains, while optimizing for available capacity in the availability domain. To change the fault domain for an instance, terminate it and launch a new instance in the preferred fault domain.
Use fault domains to do the following things:
Protect against unexpected hardware failures or power supply failures.
Protect against planned outages because of Compute hardware maintenance.
We can use fault domains to do the following things:
1) Protect against unexpected hardware failures or power supply failures.
2) Protect against planned outages because of Compute hardware maintenance

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

You can think of a Dynamic Routing Gateway (DRG) as a virtual router that provides a path for private traffic (that is, traffic that uses private IPv4 addresses) between your VCN and networks outside the VCN’s region.
For example, if you use an IPSec VPN or Oracle Cloud Infrastructure FastConnect (or both) to connect your on-premises network to your VCN, that private IPv4 address traffic goes through a DRG that you create and attach to your VCN. For scenarios for using a DRG to connect a VCN to your on-premises network, see Networking Scenarios. For important details about routing to your on-premises network, see Routing Details for Connections to Your On-Premises Network.
Also, if you decide to peer your VCN with a VCN in another region, your VCN’s DRG routes traffic to the other VCN over a private backbone that connects the regions (without traffic traversing the internet). For information about connecting VCNs in different regions, see Remote VCN Peering (Across Regions).

Service Plane is NOT an SLA provided by OCI. See the table below: