[cups.general] query about the cups class scheduling algorithm

[Ashley GC]

Hi cups fans,

Needless to say, I've checked the documentation and the newsgroups 
with no success, so:

Why does cups schedule a job sent to a class on a printer which is 
unavailble (e.g. turned off) ?

( Versions: 
distro: RedHat 9
cups version: From RedHat RPM: cups-1.1.17-13.3.0.3
kernel: From RedHat RPM: kernel-2.4.20-30.9
)

As a text, I have created a class with two printers, and leave one 
printer turned off. I send a job, which goes to the first printer, I 
then wait a few minutes, then send another job, which gets sent to the 
second printer. Except it's turned off so it stays in the queue.

The function that seems to be the cause is FindAvailablePrinter in 
scheduler/classes.c, and it does not seem to take into account the 
current state of the printer being checked, except to see if it's 
(last known?) status is idle.

Is this functionality considered ok, or is under review?, in which 
case I'd like to suggest:
- dynamic load balancing of jobs on queues on the same class
- monitoring of printers (ICMP pings, or better, test-connects to the 
  port that will be used (tcp/631, tcp/515, ...)

Thanks in advance,

Ashley GC.