backend availability

[Ashish Nepal]

Hi all,

Is there any work around so that i could say -> minimum set of 
backendserver has to be x if not available add from reserve pool.

e.g. -> i have 5 web servers -> web1,2,3,4,5
             i have reserve pool of 5 web servers -> web6,7,8,9,10


director activepool round-robin {
     { .backend = web1; }
     { .backend = web2; }
     { .backend = web3; }
     { .backend = web4; }
     { .backend = web5; }
}

director reservepool round-robin {
     { .backend = web6; }
     { .backend = web7; }
     { .backend = web8; }
     { .backend = web9; }
     { .backend = web10; }
}

and if web1 is down or web1/2 is down depends upon setting of what is 
minimum set of boxes required. i would like director to pull one of the 
box from reservepool.

or, should this be worth having such feature on backendpolling?



Regards
Ashish