Advantages of a large number of threads cf other approaches?
Tue Feb 17 12:51:17 CET 2004
On Tue, 17 Feb 2004, Joachim Durchholz wrote:
> Joe Armstrong wrote:
> > Interestingly Erlang and Apache perform equally when both are
> > unloaded - this is hardly surprising since the heavy stuff in
> > the Erlang I/O routines is all written in C and the programs are
> > "BIF bound" - but under conditions of massive overload the story
> > is very different.
> > To see how things shape up under massive overload see:
> > http://www.sics.se/~joe/apachevsyaws.html
> > In this experiment Apache crashed when subject to a load of about
> > 4000 parallel sessions - the Erlang web server (yaws) was
> > happily ticking along at 80,000 parallel sessions.
> That's interesting.
> Joe, would you or Ali be interested in running the same test with a
> Linux 2.6 kernel? They implemented an O(1) scheduler there, and it would
> help to determine whether Apache's crash is due to OS process issues or
> due to Apache.
Right now I don't have any time to re-do the tests.
My guess is that the problem lies in the kernel. At 4000+ processes
both Java and C++ started behaving in a wierd manner - I don't think
this was a co-incidence.
> Currently looking for a new job.
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