how many vda's can one delivery controller handle?
If the database is available again the principle broker instruct the secondary broker to stop listening. When the VDA communicates with the Delivery Controller a re-registration process is taken place. Currently the feature can handle up to 5000 VDAs, which sound logical as Citrix also mentions that one Delivery Controller can handle up to 5000 VDAs. Logically the secondary broker requires resources to function, check the Citrix article for all figures.