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I'm trying to capture all of the traffic to and from an Apache2 web server for troubleshooting purposes, so I did the following to try to set mod_dumpio up properly:

  1. Used a2enmod to enable mod_dumpio
  2. Changed LogLevel to "debug" in apache2.config
  3. Added "DumpIOInput On", "DumpIOOutput On" and "DumpIOLogLevel debug" to apache2.config
  4. Issued "/etc/init.d/apache2 restart" to restart Apache
  5. Issued "apache2ctl -t -D DUMP_MODULES" to make sure mod_dumpio was loaded

I'm watching /var/log/apache2/error.log, but not seeing much there, and certainly not a dump of all input and output.

Can anyone help?

share|improve this question it!

The problem was apparently that just one of my VirtualHosts (as defined in /etc/apache2/sites-enabled) had a LogLevel declared that was something other than debug, thus interfering with the overall behavior of mod_dumpio for reasons that escape me :)

I hope someone else finds this helpful.

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Note that if the LogLevel directive is set anywhere in the base httpd.conf or apache2.conf, it will prevent the module from logging (despite what the Apache docs seem to indicate). – Bruce Alderson Aug 2 '11 at 18:50

I've been struggling with this for a day, too. It seems they moved mod_dumpio output to the log level 'trace7' and disabled parameter DumpIOLogLevel.

I needed

LogLevel trace8


LogLevel info dumpio:trace8

for it to work.

Do remember that you usually have LogLevel at two levels, server level and virtual host level, check both.

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