Proxy hiccups with WSAEADDRINUSE

["Tikka, Sami" <Sa...@F-Secure.com>]

We are using httpd 2.0.48 as a forward proxy. We run on Windows 2000 and 2003
servers and have seen weird errors when the load is high. Proxy vomits in the
error log:

[error] (OS 10048)Only one usage of each socket address (protocol/network
address/port) is normally permitted.  : proxy: HTTP: attempt to connect to
1.2.3.4:80 (1.2.3.4) failed

... hundreds of megabytes of these errors.

10048 is WSAEADDRINUSE. It seems to happen in proxy_util.c in
ap_proxy_connect_to_backend() when apr_connect() is called. 

My interpretation is that the host is out of free local ports. 'netstat' also
shows a very large number of connections.

Is my interpretation correct? Is there anything that can be done? Has anyone
else seen this?

-- 
Sami Tikka, senior software engineer, F-Secure Corporation
tel: +358 9 2520 5115, fax: +358 9 2520 5015
http://www.F-Secure.com
BE SURE.

Re: Proxy hiccups with WSAEADDRINUSE

[Jeff Trawick <tr...@attglobal.net>]

Tikka, Sami wrote:

> [error] (OS 10048)Only one usage of each socket address (protocol/network
> address/port) is normally permitted.  : proxy: HTTP: attempt to connect to
> 1.2.3.4:80 (1.2.3.4) failed
> 
> ... hundreds of megabytes of these errors.
> 
> 10048 is WSAEADDRINUSE. It seems to happen in proxy_util.c in
> ap_proxy_connect_to_backend() when apr_connect() is called. 
> 
> My interpretation is that the host is out of free local ports. 'netstat' also
> shows a very large number of connections.
> 
> Is my interpretation correct? Is there anything that can be done? Has anyone
> else seen this?

your interpretation sounds correct to me

see http://www.ncftpd.com/ncftpd/doc/misc/ephemeral_ports.html#Windows