On Nov 13, 2012, at 5:58 AM, Nick Kew <n...@webthing.com> wrote: > As to what that represents, that must surely depend on the bottlenecks > in a particular system. A backend doing heavy number-crunching and > one doing lots of complex SQL queries have different loads, and a > good load measure for one may be meaningless if applied to the other. > How would a 'universal' measure reflect that kind of difference? > > Where I think you could usefully focus is on standardising a protocol > for backends to communicate loads to balancers. That then becomes > something we can implement in an lb method module in HTTPD. > But it has to be left to individual backend systems exactly how they > measure their own loads.
Yeah, and that can be "tricky" because it opens it up to becoming a marketing tool, rather than a useful load balancing tool. That's why I like a simple 0.0-1.0 scale at a minimum. Also, let's not forget that, at least which httpd, we also have load-factors and so we can weigh even what's returned by the backend. So even if they skew the results, we can always adjust for the real world.
