Re: debugging mod_proxy performance with WireShark

[Dustin Chesterman <dchester11@xxxxxxxxx>]

Thanks Igor for the reply. Sorry for not knowing quite enough to be specific with some of this. When I say it hangs, I mean every once in a while it takes 15-20 seconds to respond. When I have a direct Tomcat connection setup it doesn't happen.

mod_status was a great suggestion I did not realize was there. I'm not sure how I can use it though to debug this type of problem when many of the requests go though fine and one does not once in a while.

I removed everything that was default per your suggestion. This is my new configuration:
<VirtualHost 192.168.XXX.XXX:80>
ÂÂÂ RewriteEngine On
ÂÂÂ RewriteCond %{HTTPS} off
ÂÂÂ RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
</VirtualHost>
<VirtualHost 192.168.XXX.XXX:443>
ÂÂÂ ServerName 192.168.XXX.XXX
ÂÂÂ ProxyPreserveHost On
ÂÂÂ SSLEngine On
ÂÂÂ SSLCertificateFile /etc/httpd/ssl/jirassl-pem.crt
ÂÂÂ SSLCertificateKeyFile /etc/httpd/ssl/jirassl.key
ÂÂÂ ProxyPass / http://localhost:8080/ disablereuse=off
ÂÂÂ ProxyPassReverse / http://localhost:8080/
</VirtualHost>

I also added the diablereuse key.

I have not used the AJP connection since the warning message about an open proxy scared me off. Would this be an issue for a reverse proxy? Would this cause issues that last a long as I am seeing?

I have a capture of the problem in a wireshark log. Is there something I can look for in there that would point me in the right direction to filtering his down?

Thanks again for your help and patience :)

-Dustin
From ÂÂÂ Igor GaliÄ <i.ga...@xxxxxxxxxxxxxx>
Subject ÂÂÂ Re: [users@httpd] debugging mod_proxy performance with WireShark
Date ÂÂÂ Wed, 13 Oct 2010 20:53:35 GMT

----- "Dustin Chesterman" <dchester11@xxxxxxxxx> wrote:

> Hey all-
> I wasn't sure if I posted this correctly since I did it before my
> confirmation email from subscribing and it looked different in the

Welcome Dustin,

> archives. I'm looking for any ideas why my apache proxy would be
> causing such a huge performance hit to our web app. Thanks! :)
> 
> ---------- Forwarded message ----------
> From: Dustin Chesterman < dchester11@xxxxxxxxx >
> To: users@xxxxxxxxxxxxxxxx
> Date: Tue, 12 Oct 2010 10:24:35 -0700
> Subject: debugging mod_proxy performance with WireShark
> Hi all-
> I am new to Apache httpd and have gotten about as far as I can
> debugging some performance problems we are having on a machine. It is
> a VM with Fedora 13 installed. I am running a stand alone JIRA Tomcat
> installation on port 8080 and running httpd with mod_proxy as a
> reverse proxy on the same box. If I remove the httpd layer and go
> directly to Tomcat the performance is normal. When I add the httpd
> layer it slows down overall and hangs dramatically fairly often. I
> installed Wireshark and have captured some requests but I'm not really
> sure what I'm looking for. How can I tell what's going on in the time
> between some of the traffic going on? I also configured Flood but that
> doesn't seem to offer me any insight into what is causing the problem
> either. I'm likely not using these tools quite right but I can't seem
> to find out what I should be looking for.

How, exactly, does a hanging look like?
What does mod_status say?

> Here are my two VHosts. I am redirecting to HTTPS also, but if I take
> that layer out, it still has performance issues.
> 
> <VirtualHost *:80>
> RewriteEngine On
> RewriteCond %{HTTPS} off
> RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
> </VirtualHost>
> <VirtualHost 192.168.XXX.XXX:443>
> #<VirtualHost 192.168.XXX.XXX:80>
> ServerName 192.168.XXX.XXX
> ProxyRequests Off

ProxyRequests off is default

> ProxyPreserveHost On
> SSLEngine On
> SSLCertificateFile /etc/httpd/ssl/jirassl-pem.crt
> SSLCertificateKeyFile /etc/httpd/ssl/jirassl.key
> ProxyPass / http://localhost:8080/
> ProxyPassReverse / http://localhost:8080/

When using HTTP, I greatly suggest you set disablereuse=on, see:
https://issues.apache.org/bugzilla/show_bug.cgi?id=45362
for reference

> <Proxy *>
> Order deny,allow
> Allow from all

This is default too.

> </Proxy>
> </VirtualHost>
> 
> 
> Any suggestions insight into where i can find info to help me learn to
> debug issues with httpd in general would be greatly appreciated.

Try the disablereuse, try AJP as alternative.
Â
> Thanks all
> -Dustin Chesterman

i
-- 
Igor GaliÄ

Tel: +43 (0) 664 886 22 883
Mail: i.galic@xxxxxxxxxxxxxx
URL: http://brainsware.org/

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