DNS GSLB for Disaster Recovery

While application data controllers (or load balancers) are capable of distributing application traffic towards servers within the data center, a global server load balancing (GSLB) solution enhances this to cover multi-data center strategies. GSLB can also prove valuable for disaster recovery scenarios based on activating dedicated IT resources in a specific spare data center. DNS combined with GSLB offers an easy and efficient way to simplify the required network operations. EfficientIP application repository eases the preparation phase of the IT Disaster Recovery Plan (DRP) and DNS GSLB can be used to perform the actual switchover in case of disaster.

DNS Simplifies Disaster Recovery Switchover

Since the early days of IP networks, DNS service has been used to perform application migration from one server to another by simply changing the IP address resolved behind an FQDN. Part of the operations performed during an IT disaster recovery DNS switchover consist of changing the IP addresses associated with application resources like server names or virtual endpoints. With this approach, the entire IT ecosystem – including the client devices and applications – does not need to be reconfigured. This is of huge value to IT teams as well as users. DNS recovery is a very pragmatic approach but requires manual configuration actions. This is likely to be time-consuming as there could be a high number of FQDNs that require reconfiguration. However, it is possible to re-configure the DNS records with an automated process. This necessitates an orchestration tool with the appropriate interface to the DNS system, or strong scripting expertise if directly manipulating the database of the engines.

Planning the operations to be performed during the effective switchover is a mandatory phase where the EfficientIP application repository can be valuable. It allows network and application administrators to specify the backup IP address that would be used during the disaster recovery period. The meta-data associated with the application and FQDN can be adapted to the DRP organization, bringing important flexibility. For example, at the application level, a specific meta-data can be added to specify the switchover priority conforming to the BIA (Business Impact Analysis).

DNS GSLB is a powerful tool for Disaster Recovery Plans

During the switchover, since this kind of operation is not frequent (hopefully), actions to be performed should be simple, understandable and easy to execute. Changing the configuration of the DNS entries for multiple applications can be confusing and may lead to errors. DNS GSLB can be used to prepare the scenario and ease the activation. Nodes can be inserted in pools with the status set to “unmanage”. These nodes will not be selected for receiving traffic during normal operations, but GSLB configuration will be prepared for when the switchover occurs.

During the disaster recovery phase, switching the manage status of the nodes, based on application priority, will automatically change the DNS configuration on all the servers and direct the user application traffic towards the services located in the backup data center.

For more mature IT teams where automation has been adapted, the coupling of the DRP orchestrator with SOLIDserver through APIs can allow even more robust and easier switchover of all the DNS records, either with the standard DNS module or the more advanced DNS GSLB. This approach provides potential for more evolved scenarios and a higher integration level between IT repositories and switchover tools like VMware Site Recovery Manager (aka SRM).

Incorporating DRP with the support of EfficientIP’s DNS GSLB solution offers the ability to use its edge load balancing feature for all normal operations, meaning IT is providing a service to its users and customers most of the time. The unique Edge GSLB application traffic routing solution allows multi-data center load balancing of user traffic towards applications, improved user experience and advanced failure bypass options.

In a nutshell

• DRP is really important in terms of preparation for business continuity. It has to occur after a major disaster, so operations should be easy to perform, straightforward and efficient.
• Planning the operation is an ongoing process within the IT department. EfficientIP application repository can help modelize data to prepare the technical tasks to be performed in the event of a disaster (”IP Golden Record” approach).
• EfficientIP DNS GSLB can be configured to ease the switchover, and automation through the SOLIDserver APIs can keep manual and error-prone actions to a minimum. In normal conditions, edge DNS GSLB optimizes routing of user traffic towards appropriate services and significantly improves user experience.