Re: [libvirt] [PATCH] libxl: open libxl log stream with libvirtd log_level

On Tue, Sep 15, 2015 at 11:21:00AM -0600, Jim Fehlig wrote: > Daniel P. Berrange wrote: > > On Tue, Sep 15, 2015 at 10:57:50AM -0600, Jim Fehlig wrote: > > > >> Daniel P. Berrange wrote: > >> > >>> On Tue, Sep 15, 2015 at 09:26:23AM -0600, Jim Fehlig wrote: > >>> > >>> > >>>> Instead of a hardcoded DEBUG log level, use the overall > >>>> daemon log level specified in libvirtd.conf when opening > >>>> a log stream with libxl. libxl is very verbose when DEBUG > >>>> log level is set, resulting in huge log files that can > >>>> potentially fill a disk. Control of libxl verbosity should > >>>> be placed in the administrator's hands. > >>>> > >>>> Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; > >>>> --- > >>>> src/libxl/libxl_conf.c | 18 +++++++++++++++++- > >>>> 1 file changed, 17 insertions(+), 1 deletion(-) > >>>> > >>>> > >>> ACK, this makes sense as default behaviour. As a future enhancement > >>> you might also consider supporting a config setting in /etc/libvirt/libxl.conf > >>> to explicitly control the libxl library logging behaviour independantly. > >>> > >>> > >> I had actually thought of adding it there first, but then took this > >> approach assuming it would be more receptive upstream :-). Personally, > >> I'm on the fence. I like the idea of a single knob to control log level > >> throughout the daemon, making it a bit easier on admins. On the other > >> hand, individual knobs are more friendly to those pouring through logs. > >> I can add a knob in libxl.conf if preferred. > >> > > > > After thinking about it some more, I could actually see value in > > create a dedicated virLogSource() instance, solely for libxl > > library messages. If we then created a virLogSourceGetPriority() > > method, you could query that to see if to turn on logging for > > the libxl library. That would ultimately allow you to turn on > > debug for just the libxl library if desired, eg > > > > static virLogSource virLogLibXL = { > > .name = "libxl.libxl_library", > > .... > > } > > > > LIBVIRT_LOG_FILTERS="1:libxl_library" > > > > Ah, good idea. I'll look into it. Is it done anywhere? If not, how can I help? This the above change (setting libxl log level to libvirtd global one), makes almost impossible to get libxl debug, because the rest of libvirtd trashes the logs (hundreds virEvent* and virObject* messages, at "info"(!) level).