Re: Clarification on Xitami DoS

[full-disclosure () lists netsys com (Muhammad Faisal Rauf Danka)]

It could be an  error in Xitami's dynamic-store allocation logic that causes it to fail to reclaim the discarded memory 
per connection ?

Call for Memory Leak Detection Tools
http://www.cs.colorado.edu/homes/zorn/public_html/MallocDebug.html



Regards, 
---------
Muhammad Faisal Rauf Danka

Chief Technology Officer
Gem Internet Services (Pvt) Ltd.
web: www.gem.net.pk


--- "Matthew Murphy" <mattmurphy () kc rr com> wrote:
> > What is vendor's status regarding this issue?
>
> I've e-mailed the vendor, but have received no response *at all*.
>
> > It is good we found the real cause of DoS effect in Xitami.
> > Because, the maxedout values seem to work quiet fine, the problem is
> > Keep-Alive Connection handling.
>
> Yes, I originally thought it was a connection flood because numbers
> started jumping and then Xitami crashed almost immediately.  However,
> I was actually seeing the effects of my flood combined with numerous
> other connections that had "hung open".
>
> > I don't know how did you actually find out when it has dropped a
> > particular connection
>
> Well, I didn't find out when it was dropping connections, just that
> it *wasn't* dropping any.  My WinME box btw required an
> extremely high number of connections to crash (I believe the number
> was over 450), so production machines will require significantly
> more connections -- it seems to be a bug-induced resource exhaustion.
>
> > as in the duration of Keep-Alive affected and
> > it's connection dropping time and whether it matches the value in
> configurations? after how long ?
> > I tried netstat -an frequently by making requests from different hosts on
> my network, but same results as i told you before.
>
> I'm still a bit hazy on exactly *where* in the keep-alive handling that
> Xitami is buggy -- I'm beginning to think that it is not actually related
> to an open connection, and instead just a bad resource cleanup on
> the server end.

_____________________________________________________________
---------------------------
[ATTITUDEX.COM]
http://www.attitudex.com/
---------------------------

_____________________________________________________________
Promote your group and strengthen ties to your members with email () yourgroup org by Everyone.net  
http://www.everyone.net/?btn=tag