Regions and Availability Domains

This topic describes the physical and logical organization of Oracle Cloud Infrastructure resources.

About Regions and Availability Domains

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. Most Oracle Cloud Infrastructure resources are either region-specific, such as a virtual cloud network, or availability domain-specific, such as a compute instance. Traffic between availability domains and between regions is encrypted. 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.

The availability domains within the same region are connected to each other by a low latency, high bandwidth network, which makes it possible for you to provide high-availability connectivity to the internet and on-premises, and to build replicated systems in multiple availability domains for both high-availability and disaster recovery.

Oracle is adding multiple cloud regions around the world to provide local access to cloud resources for our customers. To accomplish this quickly, we’ve chosen to launch regions in new geographies with one availability domain.

As regions require expansion, we have the option to add capacity to existing availability domains, to add additional availability domains to an existing region, or to build a new region. The expansion approach in a particular scenario is based on customer requirements as well as considerations of regional demand patterns and resource availability.

For any region with one availability domain, a second availability domain or region in the same country or geo-political area will be made available within a year to enable further options for disaster recovery that support customer requirements for data residency where they exist.

Regions are independent of other regions and can be separated by vast distances—across countries or even continents. Generally, you would deploy an application in the region where it is most heavily used, because using nearby resources is faster than using distant resources. However, you can also deploy applications in different regions for these reasons:

  • To mitigate the risk of region-wide events such as large weather systems or earthquakes.
  • To meet varying requirements for legal jurisdictions, tax domains, and other business or social criteria.

Regions are grouped into realms . Your tenancy exists in a single realm and can access all regions that belong to that realm. You cannot access regions that are not in your realm. Currently, Oracle Cloud Infrastructure has multiple realms. There is one commercial realm. There are multiple realms for Government Cloud: US Government Cloud FedRAMP authorized and IL5 authorized, and United Kingdom Government Cloud.

The following table lists the regions in the Oracle Cloud Infrastructure commercial realm :

Region Name Region Identifier Region Location Region Key Realm Key Availability Domains
Australia East (Sydney) ap-sydney-1 Sydney, Australia SYD OC1 1
Australia Southeast (Melbourne) ap-melbourne-1 Melbourne, Australia MEL OC1 1
Brazil East (Sao Paulo) sa-saopaulo-1 Sao Paulo, Brazil GRU OC1 1
Brazil Southeast (Vinhedo) sa-vinhedo-1 Vinhedo, Brazil VCP OC1 1
Canada Southeast (Montreal) ca-montreal-1 Montreal, Canada YUL OC1 1
Canada Southeast (Toronto) ca-toronto-1 Toronto, Canada YYZ OC1 1
Chile (Santiago) sa-santiago-1 Santiago, Chile SCL OC1 1
Germany Central (Frankfurt) eu-frankfurt-1 Frankfurt, Germany FRA OC1 3
India South (Hyderabad) ap-hyderabad-1 Hyderabad, India HYD OC1 1
India West (Mumbai) ap-mumbai-1 Mumbai, India BOM OC1 1
Japan Central (Osaka) ap-osaka-1 Osaka, Japan KIX OC1 1
Japan East (Tokyo) ap-tokyo-1 Tokyo, Japan NRT OC1 1
Netherlands Northwest (Amsterdam) eu-amsterdam-1 Amsterdam, Netherlands AMS OC1 1
Saudi Arabia West (Jeddah) me-jeddah-1 Jeddah, Saudi Arabia JED OC1 1
South Korea Central (Seoul) ap-seoul-1 Seoul, South Korea ICN OC1 1
South Korea North (Chuncheon) ap-chuncheon-1 Chuncheon, South Korea YNY OC1 1
Switzerland North (Zurich) eu-zurich-1 Zurich, Switzerland ZRH OC1 1
UAE East (Dubai) me-dubai-1 Dubai, UAE DXB OC1 1
UK South (London) uk-london-1 London, United Kingdom LHR OC1 3
UK West (Newport) uk-cardiff-1 Newport, United Kingdom CWL OC1 1
US East (Ashburn) us-ashburn-1 Ashburn, VA IAD OC1 3
US West (Phoenix) us-phoenix-1 Phoenix, AZ PHX OC1 3
US West (San Jose) us-sanjose-1 San Jose, CA SJC OC1 1

To subscribe to a region, see Managing Regions.

For a list of regions in the the Oracle Government Cloud realms, see the following topics:


Your Tenancy's Availability Domain Names

Oracle Cloud Infrastructure randomizes the availability domains by tenancy  to help balance capacity in the data centers. For example, the availability domain labeled PHX-AD-1 for tenancyA may be a different data center than the one labeled PHX-AD-1 for tenancyB. To keep track of which availability domain corresponds to which data center for each tenancy, Oracle Cloud Infrastructure uses tenancy-specific prefixes for the availability domain names. For example: the availability domains for your tenancy are something like Uocm:PHX-AD-1, Uocm:PHX-AD-2, and so on.

To get the specific names of your tenancy's availability domains, use the ListAvailabilityDomains operation, which is available in the IAM API. You can also see the names when you use the Console to launch an instance and choose which availability domain to launch the instance in.

Fault Domains

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 a compute instance, edit the fault domain. To change the fault domain for a bare metal or virtual machine DB system 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.

For more information:

Subscribed Region Limits

Trial, free tier, and pay-as-you-go tenancies are limited to one subscribed region. You can request an increase to the limit for pay-as-you-go tenancies, see To request a subscribed region limit increase for more information.

Universal monthly credit tenancies can subscribe to all publicly released commercial regions.

Requesting a Limit Increase to the Subscribed Region Count

You can submit a request to increase the subscribed region count for your tenancies from within the Console. If you try to subscribe to a region beyond the limit for your tenancy, you'll be prompted to submit a limit increase request. Additionally, you can launch the request from the service limits page or at any time by clicking the link under the Help menu (Help menu icon).

To request a subscribed region limit increase
  1. Open the Help menu (Help menu icon), go to Support and click Request service limit increase.

  2. Enter the following:

    • Primary Contact Details: Enter the name and email address of the person making the request. Enter one email address only. A confirmation will be sent to this address.
    • Service Category: Select Regions.
    • Resource: Select Subscribed region count.
    • Tenancy Limit: Specify the limit number.
    • Reason for Request: Enter a reason for your request. If your request is urgent or unusual, please provide details here.
  3. Click Submit Request.

After you submit the request, it is processed. A response can take anywhere from a few minutes to a few days. If your request is granted, a confirmation email is sent to the address provided in the primary contact details.

If we need additional information about your request, a follow-up email is sent to the address provided in the primary contact details.

Service Availability Across Regions

All Oracle Cloud Infrastructure regions offer core infrastructure services, including the following:

  • Compute: Compute (Intel-based bare metal & VM, DenseIO & Standard), Container Engine for Kubernetes, Container Registry, Artifact Registry
  • Storage: Block Volume, File Storage, Object Storage, Archive Storage
  • Networking: Virtual Cloud Network, Load Balancing, FastConnect (specific partners as available and requested)
  • Database: Database, Exadata Cloud Service, Autonomous Data Warehouse, Autonomous Transaction Processing
  • Edge: DNS
  • Platform: Audit, Identity and Access Management, Monitoring, Notifications, Tagging, Work Requests
  • Security: Vault

Generally available cloud services beyond those in the previous list are made available based on regional customer demand. Any service can be made available within a maximum of three months, with many services deploying more quickly. New cloud services are made available in regions as quickly as possible based on a variety of considerations, including regional customer demand, ability to achieve regulatory compliance where applicable, resource availability, and other factors. Because of Oracle Cloud Infrastructure's low latency interconnect backbone, you can use cloud services in other geographic regions with effective results when those services are not available in your home region, as long as data residency requirements do not prevent you from doing so. We regularly work with customers to help ensure effective access to required services.

Resource Availability

The following sections list the resource types based on their availability: across regions, within a single region, or within a single availability domain.


In general: IAM resources are cross-region. DB Systems, instances, and volumes are specific to an availability domain. Everything else is regional. Exception: Subnets were originally designed to be specific to an availability domain. Now, you can create regional subnets, which are what Oracle recommends.

Cross-Region Resources

  • API signing keys
  • compartments
  • detectors (Cloud Guard; regional to reporting region)
  • dynamic groups
  • federation resources
  • groups
  • managed lists (Cloud Guard)
  • network sources
  • policies
  • responders (Cloud Guard; regional to reporting region)
  • tag namespaces
  • tag keys
  • targets (Cloud Guard; regional to reporting region)
  • users

Regional Resources

  • agents (Database Migration)
  • alarms
  • apm-domains (Application Performance Monitoring)
  • applications (Data Flow service)
  • applications (Functions service)
  • artifact-repositories (Artifact Registry)
  • bastions
  • blockchain platforms (Blockchain Platform service)
  • buckets: Although buckets are regional resources, they can be accessed from any location if you use the correct region-specific Object Storage URL for the API calls.
  • clusters (Big Data service)
  • clusters (Container Engine for Kubernetes service)
  • cloudevents-rules
  • config work requests (Logging Analytics)
  • configuration source providers (Resource Manager)
  • connections (Database Migration)
  • content and experience (Content Management)
  • customer-premises equipment (CPE)
  • dashboards (Management Dashboard)
  • data catalogs
  • database insights (Operations Insights)
  • DB Systems (MySQL Database service)
  • deployments (GoldenGate)
  • devops projects (DevOps)
  • deployment pipelines (DevOps)
  • DHCP options sets
  • dynamic routing gateways (DRGs)
  • encryption keys
  • entities (Logging Analytics)
  • fleets (Java Management)
  • functions
  • generic-artifacts (Artifact Registry)
  • host scans
  • images
  • internet gateways
  • jobs (Database Management)
  • jobs (Database Migration)
  • jobs (Resource Manager)
  • load balancers
  • local peering gateways (LPGs)
  • log groups (Logging Analytics)
  • management agent install keys
  • management agents
  • managed database groups (Database Management)
  • managed databases (Database Management)
  • metrics
  • migrations (Database Migration)
  • models
  • NAT gateways
  • network security groups
  • node pools
  • notebook sessions
  • object collection rules (Logging Analytics)
  • port scans
  • private endpoints (Database Management)

  • private endpoint work requests (Database Management)

  • private templates (Resource Manager)
  • problems (Cloud Guard; regional to reporting region)
  • projects
  • queryjob work requests (Logging Analytics)
  • registered databases (GoldenGate)
  • repositories
  • reserved public IPs
  • route tables
  • runs
  • saved searches (Management Dashboard)
  • scan recipes
  • scheduled tasks (Logging Analytics)
  • secrets
  • security lists
  • security zones
  • service connectors
  • service gateways
  • sessions (Bastion)
  • stacks (Resource Manager)
  • storage work requests (Logging Analytics)
  • subnets: When you create a subnet, you choose whether it's regional or specific to an availability domain. Oracle recommends using regional subnets.
  • subscriptions
  • tables
  • targets (Vulnerability Scanning)
  • tickets (Support Management service)
  • topics
  • vaults
  • virtual cloud networks (VCNs)
  • volume backups: They can be restored as new volumes to any availability domain within the same region in which they are stored.
  • vulnerability reports
  • workspaces

Availability Domain-Specific Resources

  • DB systems (Oracle Database service)
  • ephemeral public IPs
  • instances: They can be attached only to volumes in the same availability domain.
  • subnets: When you create a subnet, you choose whether it is regional or specific to an availability domain. Oracle recommends using regional subnets.
  • volumes: They can be attached only to an instance in the same availability domain.