httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Plüm, Rüdiger, VF-Group <ruediger.pl...@vodafone.com>
Subject Re: [PATCH] Apache 2.2.x: Implicit creation of new proxy_workers
Date Mon, 10 Sep 2007 10:01:57 GMT


> -----Ursprüngliche Nachricht-----
> Von: Nick Kew 
> Gesendet: Montag, 10. September 2007 11:29
> An: dev@httpd.apache.org
> Betreff: Re: [PATCH] Apache 2.2.x: Implicit creation of new 
> proxy_workers
> 
> 
> On Tue, 4 Sep 2007 14:19:23 +0200
> Axel-Stéphane  SMORGRAV <Axel-Stephane.SMORGRAV@europe.adp.com> wrote:
> 
> > I will create a Bugzilla report for this issue.
> 
> That'll be PR#43308, in which you wrote:
> 
> > In Apache 2.2.x a worker, and the associated backend 
> connection pool,
> > is created for each ProxyPass directive. In that case the backend
> > connections will by default be persistent (reusable).
> 
> > (chop - RewriteRule [P])
> 
> > I therefore suggest to modify ap_proxy_pre_request() in order to
> > create new workers as needed in the event of requests that do not
> > match an existing worker.
> 
> Does this open the way to a DoS?  If a rewriterule[P] enables backends
> to be derived from the request URI, then you're creating unlimited
> numbers of workers, which may never be used.  Where are the limits
> on that?

Also the scoreboard is a limiting factor for this. The number of available
scoreboard entries is determined during the configuration phase of the
startup (it cannot even be changed during graceful starts, this is why we
add some additional entries to the number of workers we have counted in the
configuration).

To be honest I am still not convinced that the dynamic creation of workers
is a good idea at all.

Regards

Rüdiger



Mime
View raw message