getting to yaws

Joe Armstrong <>
Thu Jul 4 10:31:06 CEST 2002

On Wed, 3 Jul 2002, Jimmie Houchin wrote:

> Hello,
> I recently downloaded yaws-5.1 and tested it and ran a few (ab) 
> benchmarks and did similarly to Apache, AOLServer, thttpd, etc.
> Very impressive. I'll post results and questions later. They are on a 
> different machine at home.

If you are doing benchmarks then the following question is
very interesting.

How well does yaws work in the presence of overload, and how
well does yews work in the presences of massing simulatenous access.

I want to measure the following:

1) raw page rate (one user multiple connects)

2) Set up (say) 20,000 sockets and dribble data into them - make
the HTTP requests very slowly ( 1 byte/sec).
   Then set up one fast client (as in 1) and measure the page rate

   Do 2) varying the number of slow sockets

   Plot the page rate/# slow sockets connections

   Compare with Apache.

   I think the results might be surprising :-)

3) Measure the throughput as you massivly overload the system.

   (say the page rate is 1000 pages/sec)

   Subject the system to 10000 requests/sec.

   The desirable behaviour is that 10% of the traffic is accepted
90% is rejected.

   Consider only the accepted requests. How many accepted requests/sec
do we get as a function of the the input load.

  Measure this rate as a function of the overload. For the AXD301 Uffe
reports astoundingly good results here - if we can reproduce this in a
web server I think there is a good chance that we will be
be very much better than Apache etc.

  This measure tells how well  your system behaves during a denayal of
service attack.

I am very interested in the measurements 1) - 3) above.

All measurements should be normalised to a 1 GHz machine.

  I will be doing these  measurements myself so it will be interesting
to compare results.


> It gives me great encouragement and incentive to learn Erlang to use for 
> my website. I was afraid I was going to have to write Apache modules for 
> good performance. Ha! :)
> This makes me very happy. Thanks.
> I am busy going thru the Erlang materials to get up to speed.
> After recieving the below message I downloaded yaws-5.2. Several times 
> actually and now on different machines and OSes (Debian Linux and 
> WinME). All gzip utilities tell me that it isn't a gzipped archive. I 
> had know problems with the previous version.
> Anyone else had such experiences?
> Thanks for any help.
> Jimmie Houchin
> Klacke wrote:
> [snip]
> > Ok new release 0.52 ... now containing johans security bugfixes,
> > -heart support by tobbe and a wiki web.
> > 
> >   (hopefully up this time)
> > 
> > /klacke

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