is_overloaded() in schedulers

[Benoit Gaussen <ben@xxxxxxxxxx>]

Hi,

While digging around LVS code, I saw this is_overloaded() function, that
is present in many schedulers (dh, sh, lblc, lblcr) :

static inline int is_overloaded(struct ip_vs_dest *dest)
{
                if (atomic_read(&dest->activeconns) >
                                   atomic_read(&dest->weight)*2) {
                                       return 1;
                        }
          return 0;
}


This code seems to prevent scheduling to a real server if it has
more than twice its weight of active connections.

I see two problems here :
  - it is an implicit limitation of connections (ok it's why
         the function is here). There is no information about that in man...
         Moreover an attacker could open a lot of connections and disable a
         real server.
  - there is a  comparison of two values that I think are not
         equivalent and can't be compared.

Is this function really needed ? 
If ratz per real server limitation threshold get to LVS (and I hope
so...), this function will be redondant.

Regards,

Ben.

-- 
Unix IS user friendly, it is just selective about who his friends are.
                                                             Anonymous