Understanding high availability and disaster recovery for DNS Services

All IBM Cloud® general availability (GA) offerings have a Service Level Agreement of 99.99% availability. IBM Cloud® DNS Services is a GA service that is offered globally. The public API endpoints for DNS configuration are available globally through a global load balancer in two MZRs (Multi Zone Regions) of IBM Cloud, providing high availability. The regions are Dallas and Washington, DC. If one region experiences an outage, the global load balancer ensures that the API traffic gets routed to another region. For instance, if the Dallas region experiences an outage, requests get routed to the geographically nearest region, in this case, Washington, DC.

The DNS resolvers are distributed around the world in multiple MZRs with any cast IP addresses for optimizing latencies and providing high availability. If one region experiences an outage, the DNS queries are routed to another region. The data is replicated to the following regions for latency optimization and high availability:

• Dallas (us-south)
• Washington, D.C. (us-east)
• London (eu-gb)
• Madrid (eu-es)
• Frankfurt (eu-de)
• Osaka (jp-osa)
• Tokyo (jp-tok)
• Toronto (ca-tor)
• Sydney (au-syd)
• Sao Paulo (br-sao)

A best practice is to deploy custom resolvers to more than one location to ensure high availability. It is recommended that you deploy in all three availability zones.

See How do I ensure zero downtime? to learn more about the high availability and disaster recovery standards in IBM Cloud. You can also find information about Service Level Agreements.