Problem with Downloads, using Apache as Forward Proxy

[Sai Jai Ganesh Gurubaran <sg...@cordys.com>]

Hi,
	 
I have posted many queries to Apache users mailing list but has not got
any answers till now. I need to desperately get this issue solved. 

The issue is this:
        We are having Apache (version 2.0.54) installed as a forward
proxy on RHEL 3.0. 
Downloads fail more often than being successful. 


The set up:
------------------
Apache as the Forward proxy, connected to ISA server, which is in turn
connected to Firewall. Users connect to Apache as Forward proxy.

Issue:
---------
Partial/incomplete Downloading of file. 
Download starts properly after some time it suddenly says download
complete. Attempting to open the file, we get invalid/corrupt downloaded
file alert.

For e.g.: 
    if we attempt to download 116MB , download stops after 10 MB (some
time it went till 110MB).

When we directly connect to the web server, without Apache as a forward
proxy, we get successful downloads 100%.

Error log:
-------------

The error log does not show anything in 2.0.54.

Using 2.0.48, we get 
	[notice] child pid 20653 exit signal Segmentation fault (11)
and 
	[Fri Aug 12 15:02:51 2005] [notice] child pid 431 exit signal
Abort (6)

If we use Apache 2.1.6 alpha:
        (104)Connection reset by peer: proxy: error reading response

We tested all the known versions of Apache 2.0 (2.0.48, 2.0.52, 2.0.54,
2.1.6 alpha). Changed the OS to RHEL 4.0 but the problem persists.

Without Apache downloads are successful.

We need to get this solved as early as possible. Please do help us in
this regard.

configuration of the HTTPD:
Note:
    The changed httpd.conf entries are as follows:

<IfModule worker.c>
StartServers       15
MaxClients        750
MinSpareThreads    25
MaxSpareThreads    750
ThreadsPerChild     50
MaxRequestsPerChild  0
#ServerLimit          10
MaxMemFree      2000
</IfModule>

#Apache as Proxy
ProxyRequests On


(Everything else is default conf file.)

Thanks and Regards,
Sai Jai Ganesh. G 


Also, the recent log by Gerrit is the same situation as ours.

I Quote his post:
-----Original Message-----
From: Gerrit van der Kolk 
Sent: Monday, August 22, 2005 5:31 PM
To: users@httpd.apache.org
Subject: [users@httpd] apache forward proxy download problem


Hi,
I'm facing a problem when using apache with mod_proxy module configured
as forward proxy. Downloads fail more often than there successful.
Especially large downloads(10MB+), but also the small ones. I have tried
to use different combinations of configurations to eliminate the
problem, but the problem is still there. The problem is reproducible on
different hardware, 2 different linux versions( Redhat Enterprise 3 and
Redhat Enterprise 4) and different apache versions(2.0 and I also tried
the 2.1 alpha version). I also tried to compile mod_proxy support into
apache, not with modules. That doesn't make the difference. Things I see
in the error_log of apache 2.1 are:

(104)Connection reset by peer: proxy: error reading response

error_log of apache 2.0:
[notice] child pid 20653 exit signal Segmentation fault (11) and [Fri
Aug 12 15:02:51 2005] [notice] child pid 431 exit signal Abort (6) I
added a rule to the apache configuration to force the use of http-1.0
and not to use keepalives, but downloads still fail. Apache is compiled
with mpm=worker Does anyone have a solution for this? Or is this maybe a
bug in apache/mod_proxy?

Regards,
Gerrit


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Re: Problem with Downloads, using Apache as Forward Proxy

[r....@t-online.de]

Hi,

Sai Jai Ganesh Gurubaran wrote:


[..cut..]

> 
> Error log:
> -------------
> 
> The error log does not show anything in 2.0.54.
> 
> Using 2.0.48, we get 
> 	[notice] child pid 20653 exit signal Segmentation fault (11)
> and 
> 	[Fri Aug 12 15:02:51 2005] [notice] child pid 431 exit signal
> Abort (6)

I assume that you do not use any 3rd party modules within your Apache.
So a gdb stacktrace would be very helpful here (or even the whole coredump,
but do no post it to the list because it is too large for that.)
Please have a look

http://httpd.apache.org/docs/2.0/mod/mpm_common.html#coredumpdirectory

on how to make Apache save the core dump to a specific directory.

> 
> If we use Apache 2.1.6 alpha:
>         (104)Connection reset by peer: proxy: error reading response
> 

The error indicates that the remote host from which httpd as a forward
proxy reads the data has closed the connection (for whatever reason).

BTW: Apache 2.1.7 alpha is available in the meantime.

Regards

Rüdiger