[Zope] Re: Threading, dtml and performance?!

[Oliver Bleutgen]

Dieter Maurer wrote:

> Oliver Bleutgen writes:
>  > As I wrote before, it happens in mod_perl, it doesn't happen in zope2.3.3 on
> How does "mod_perl" do it?
> It is non-trivial...


I have no idea how theys do it, but with the perl script I posted
in another


> 
>  > And I would still be interested in an explanation why two long running 
>  > methods (not four) seem to be able to stall zopes http server on linux.
> I just checked with an "activeSleep" script:
> 
>    >   from time import time
>    >   
>    >   def sleep(sec):
>    >     e= time() + float(sec)
>    >     while time() < e: pass
>    >     print 'active sleep finished'
>    >     return 'slept'
> 
> I had three parallel "sleep" requests and a forth request could
> manage Zope without problems...
> 
> Maybe your long running methods are special?

No, but I found a explanation, ... well sort of, and the important
point is that it has nothing to do with zope.
It seems that NT limits these connections per process, because
internet explorer behaves as I described, but using tcpdump one
can see that the third request never reaches the server. Using
another http client on the same machine. while the two IE windows
are still loading. gets the zope pages without a problem.
Using mozilla I can reproduce IE's behavior, if I use a pair
of tabbed windows, but not if I open new navigator windows.

Another proof that zope can't be at fault here is that
even an apache server on the same machine is unreachable
under the conditions depicted above.

Ok, if anybody has a hint what happens here, I'm interested,
but perhaps private mail would be in order, as it doesn't
concern zope.

cheers,
oliver