If you use a Domain Name System (DNS) record to route user traffic in your data centers, the DNS record should point to a load balancer in the primary data center under normal operating situations.
If the primary data center becomes unavailable, the DNS record should be updated to point to the load balancer in the secondary data center.
When the primary data center becomes available again, the DNS record should be updated to point to the load balancer in primary data center.
Setting Time To Live in DNS Record
The time to live (TTL) setting determines how long before DNS related information is refreshed in the cache. For a seamless failover of View desktops and applications, make sure that the time to live (TTL) setting on the DNS records is short. If the TTL setting is set too long, users might not be able to access their View desktops and applications immediately after failover. To enable quick refresh of the DNS, set the DNS TTL to 30 seconds.