[libvirt] [PATCH 2/2] Improve logging documentation including the debug buffer

[Daniel Veillard]

On Thu, Mar 17, 2011 at 05:25:53PM -0600, Eric Blake wrote:
> On 03/17/2011 01:41 AM, Daniel Veillard wrote:
> > * docs/logging.html.in: document the fact that starting from
> >   0.9.0 the server logs goes to libvirtd.log instead of syslog
> >   by default, describe the debug buffer, restructure the page
> >   and add a couple more examples
> 
> > -      <li>log messages: they are information generated at runtime by
> > +      <li><b>log messages</b>: they are information generated at runtime by
> >            the libvirt code. Each message includes a priority level (DEBUG = 1,
> >            INFO = 2, WARNING = 3, ERROR = 4), a category, function name and
> >            line number, indicating where it originated from, and finally
> >            a formatted message.  In addition the library adds a timestamp
> >            at the begining of the message</li>
> 
> While you're here:
> 
> s/begining/beginning/
> 
> > -      <li>log filt> +    <p>Note that the logging module saves all logs to a <b>debug buffer</b>
> > +       filled in a round-robin fashion as to keep a full log of the
> > +       recent logs including all debug. The debug buffer can be resized
> > +       or deactivated in the daemon using the log_buffer_size variable,
> > +       default is 64 kB. This can be used when debugging the libvrary
> 
> s/libvrary/library/
> 
> > +    <p>Starting from 0.9.0, the daemon can save all the content of the debug
> > +       buffer to the defined error channels (or /var/log/libvirt/libvirtd.log
> > +       by default) in case of crash, this can also be activated explicitely
> 
> s/explicitely/explicitly/
> 
> > +       for debugging purposes by sending the daemon an USR2 signal:</p>
> 
> s/an USR2/a USR2/
> 
> > @@ -111,6 +153,9 @@
> >         will log all warnings and errors to syslog under the libvirtd ident
> >         but also log everything debugging and informations included in the
> 
> While we're here: s/log everything debugging and informations/log all
> debug and information/
> 
> >      what is happening and where things are going wrong, allowing to then
> >      put the correct breakpoints when running under a debugger.</p>
> > +    <p>To activate full debug of the libvirt entry points, utilities
> > +    functions and the QEmu/KVM driver, setting:</p>
> 
> s/utilities functions/utility functions/
> s/setting:/set:/
> 
> > +    <pre>log_filters=1:libvirt 1:util 1:qemu
> > +log_output=1:file:/var/log/libvirt/libvirtd.log</pre>
> > +    <p>in the libvirtd.conf and restarting the daemon will allow to
> > +    gather a copious amount of debugging traces for the operations done
> > +    in those areas.</p>
> > +    <p>On the other hand to deactivate the logbuffer in the daemon
> > +    for stable high load servers, set</p>
> > +    <pre>log_buffer_size=0</pre>
> > +    <p>in the libvirtd.conf.</p>
> 
> s/in the/in/
> 
> ACK with those nits fixed.

  Heh, thanks for all the fixes :-)

  Applied and pushed both !

BTW I'm clearly not a native english speaker, but "a USR2 signal" sounds
strange to me, or rather hard to pronounce, and I would have assumed that
"an" would have to be used even with an acronym, or maybe there is a
different reason :)

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/