[asterisk-users] "Cheapest" way to determine channels in a group from outside asterisk?

[Nick Adams]

I need to determine the number of active calls in a group from outside 
of Asterisk. Currently I poll the manager API and parse the channel 
status list but this is becoming too expensive on CPU.

What are my options? What is considered "standard practice" ? Update a 
DB field? Poll the manager api? Use an asterisk -rv 'some command' call?