We currently have a Virtual servers hosted on two different data centers and we have a BIGIP DNS tagged to those 2 virtual servers for the fail over purpose between the two Data centers. The way the two virtual servers configured are based on the irule, for example like /abc goes to abc pool and so on. There are few different pools that are currently in the irule and everything is based on the URI to pool redirection with a default pool too and is working as expected. so there is new requirement that came up recently like the app team wants that BIGIP DNS to be fail over between the two data centers based on the two pools that are already there in the LTM Irules. so the way it should function is that if all them members of "EITHER" pool fail the health check then the VIP will be marked as down and BIG IP DNS will then send traffic to the other datacenter. is this something that can be achieved?
You could set up multiple HTTP monitors for the DNS pool to check the different context paths. As part of the advanced options for the pool to "All Health Monitors" and if any fail it would mark that DC as down.