node select expr based on server_addr

I'm going to map a server IP address (server_addr) for a wildcard virtual server to a pool member using the following node select expression:

 

 

select node("192.168.0." + getfield("${server_addr}", '.', 4) + ":${server_port}")

 

 

Does this syntax make any sense? Will it work? Is there more efficient way to choose a pool member IP address based on the server_addr variable?

 

 

Thank you,

 

 

Dmitriy