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.