httpd-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Frode E. Moe" <>
Subject Re: [users@httpd] Apache fails to detect client closing connection with windows firewall on client
Date Thu, 23 Nov 2006 10:25:22 GMT
Exactly, but for a public-facing web site we have no saying in whether
clients use a firewall or not :(

Also, doesn't this mean that someone could effectively take down the
entire server by opening (MaxWorkers) requests every 5 minutes 
and then just not respond to / read the response at all? 

Wouldn't this make apache a very easy (D)-DoS target?

Has anyone else experienced this issue? 

Is there a way to reduce the write-to-client timeout in Apache?

FWIW, I think I'll look into PHP's built-in outbut buffering feature 
to reduce the the issue of locked PHP session files while writes time

- Frode

On Thu, Nov 23, 2006 at 11:12:52 +0100, Roman Fiedler wrote:
> Hi,
> seems to be just a firewalling/networking problem. The httpd cannot 
> operate on the protocol stack level since it does not have the right 
> privileges. It could be that your client closes the socket (FIN-ACK), 
> but the the firewall blocks further TCP-packets from the server to your 
> local protocol stack (no ack sent, remote protocol state machine goes to 
> timeout). This could be an anti-scanning/anti-DOS setting in your 
> firewall to prevent that the list of already closed connections may grow 
> too large (close-wait state?)
> roman

The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:> for more info.
To unsubscribe, e-mail:
   "   from the digest:
For additional commands, e-mail:

View raw message