Oracle Cloud Infrastructure provides several building blocks that you can use to plan for DR of your applications.
Regions, Availability Domains, and Fault Domains
Each Oracle Cloud Infrastructure region is in a geographical area that's independent and separated by vast distances—across countries or even continents, from all the other regions. You can deploy applications in different regions to mitigate the risk of region-wide events, such as large weather systems and earthquakes.
- 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 don’t 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 others. The availability domains within a region are interconnected by a low-latency, encrypted network.
- 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 enable you to distribute your resources so that they don't depend on the same physical hardware within a single availability domain. As a result, hardware failures or maintenance events that affect one fault domain do not affect the resources in other fault domains.
The Oracle Cloud Infrastructure Compute service provides both bare metal and virtual machine compute instances that deliver performance, flexibility, and control. The service is powered by Oracle’s next-generation, internet-scale infrastructure, which is designed to help you develop and run your most demanding applications and workloads in the cloud.
In the context of DR, we recommend deploying your compute instances across multiple availability domains or fault domains to protect your applications from outages. When you create compute instances, you can specify the fault domains in which to place the instances. When carrying out maintenance on the underlying compute infrastructure, Oracle ensures that only a single fault domain is impacted at a time. This practice ensures the availability of your instances in the remaining fault domains. So we recommend distributing your instances across multiple fault domains to achieve high availability.
The compute service enables you to share custom images across tenancies and regions by using the image import/export feature.
The Oracle Cloud Infrastructure Block Volumes service enables you to dynamically provision and manage block storage volumes. You can create, attach, connect, and move volumes as necessary to meet your storage and application requirements.
You can use the volume backup feature to create a point-in-time backup of data on a block volume. The backup volume provides a reliable copy of your data and enables you to successfully complete DR within the same region. You can perform manual backups or implement automated policy-driven backups.
For durability of data, multiple copies of data are stored redundantly across multiple storage servers within an availability domain. To protect against the impact of the failure or unavailability of an availability domain, we recommend making regular backups to a remote region.
The Oracle Cloud Infrastructure File Storage service provides a durable, scalable, distributed, enterprise-grade network file system. File storage is designed to meet the needs of applications and users that need an enterprise file system across a wide range of use cases.
Data is replicated for durability within each availability domain in a highly available infrastructure that implements industry-leading data protection techniques and best practices. To protect against the failure of an availability domain, we recommend making regular backups of file system snapshots to a second availability domain in the same region or in a remote region.
The Oracle Cloud Infrastructure Object Storage service is an internet-scale, high-performance storage platform that offers reliable and cost-efficient data durability. You can use this service safely and securely store or retrieve data directly from the internet or from within the cloud platform. The elasticity of the platform lets you start small and scale seamlessly, without experiencing any degradation in performance or service reliability.
Object Storage is inherently a highly durable storage service. So you don't need to back up data that is stored in Object Storage. All the objects are redundantly stored on multiple storage servers within a region. In each region, data is automatically distributed across availability domains and fault domains to maximize durability. Data integrity is continuously monitored by using checksums, and corrupt data is healed in the background without impact to usability. These native object storage durability characteristics eliminate the need for traditional backups. Object Storage is highly reliable and designed for 99.9% availability.
The Storage Gateway enables you to connect your on-premise applications with Oracle Cloud. You can use the gateway to move files to Oracle Cloud Infrastructure Archive Storage as a cost-effective backup solution. You can move individual files and compressed or uncompressed zip or tar archives.
Storing secondary copies of data is an ideal use case for Storage Gateway. By using Storage Gateway, traditional applications can move data to a highly durable object storage. When you need to recover data, a new instance of the gateway is created, and data can be easily recovered.
Oracle Cloud Infrastructure provides several network-related services and features to meet your application's DR requirements.
A virtual cloud network (VCN) is a software-defined network that you set up in Oracle data centers, with firewall rules and communication gateways that you can define. You can control whether subnets are public or private, and whether instances get public IP addresses. You can set up your VCN to have access to the internet or to be isolated. You can also privately connect your VCN to public Oracle Cloud Infrastructure services such as Object Storage, to your on-premises network, or to another VCN.
Reserved public IP addresses enable you to reassign an IP address to another instance if there is failover or failback, which simplifies the DR process.
Oracle Cloud Infrastructure FastConnect provides an easy way to create a dedicated, private connection between your on-premises data center and Oracle’s cloud infrastructure. FastConnect provides high-bandwidth options and a more reliable and consistent networking experience compared to internet-based connections.
The Oracle Cloud Infrastructure Load Balancing service provides automated traffic distribution from one entry point to multiple servers reachable from your VCN. The service offers a load balancer with your choice of a public or private IP address, and provisioned bandwidth. The load balancer can reduce your maintenance window by draining traffic from an unhealthy application server before you remove it from service for maintenance.
The Oracle Cloud Infrastructure Database service offers several types of Oracle databases. You can quickly launch a database system that meets your needs. You have full access to the features and operations available with the database, but Oracle owns and manages the infrastructure.
- Exadata DB systems
- Bare metal and virtual machine DB systems
- Autonomous databases: Autonomous Transaction Processing and Autonomous Data Warehouse
Oracle offers certified, fully supported 2-node RAC DB systems, where the platform assigns each DB node to a different fault domain by default. You can choose the fault domain for each node during provisioning. You can choose a different fault domain for each of the two DB nodes, and keep the application tier in the third fault domain to avoid any single point of failure.