httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Nick Kew <>
Subject Re: The Case for a Universal Web Server Load Value
Date Tue, 13 Nov 2012 10:58:09 GMT
A protocol for backends to communicate load to balancers in real time
has appeal.  You could hack it in HTTP or similar with
X-Server-Load: 0.1234
Perhaps a series of numbers representing different moving averages, etc.

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.

Nick Kew

View raw message