[libvirt-users] libvirt: XML-RPC error : Cannot write data: Broken pipe

[Daniel P. Berrange]

On Thu, Aug 10, 2017 at 10:45:49AM +0200, Dominik Psenner wrote:
> 2017-08-10 8:21 GMT+02:00 Michal Privoznik <mprivozn at redhat.com>:
> 
> > On 08/09/2017 03:59 PM, Dominik Psenner wrote:
> > > The error message could however give a hint what is going on. It should
> > sax
> > > that it is impossible to talk to libvirtd and that it might be stopped.
> >
> > [Please don't top post on technical lists]
> 
> 
> > Yes and no. There can be a lot of reasons why client can't talk to
> > daemon. They all don't demonstrate in local connection, but imagine
> > talking to a daemon on distant host.
> 
> And suddenly somebody cuts the
> > cable, or inserts incorrect firewall rules, etc. Suggesting that daemon
> > is not running would be wrong in this case.
> 
> 
> Actually, it would most probably be true in this case and still the most
> probable cause if the communication went over a wire. Yes, it could be a
> firewall issue but still it is more likely that the host or the service is
> not up.
> 
> 
> > Also, we tend to report
> > system errors and leave mgmt application figure out how to deal with it.
> > For instance:
> >
> > http://libvirt.org/git/?p=libvirt.git;a=blob;f=tools/virsh.c;h=
> > 94bb7ff6c93afa46d31d085eaa5e504f1cca7593;hb=HEAD#l90
> 
> 
> Are you indicating that a user should have to read the sourcecode of
> libvirt and libvirtd to understand their error messages? Please bear in
> mind that we are humans that use a software and as such the software should
> be written to be used by humans. I know very well that good error handling
> is a tough task to achieve, but it is still worth the effort. I suggest
> that the error message:
> 
> libvirt: XML-RPC error : Cannot write data: Broken pipe
> 
> should read as:
> 
> libvirt: Could not connect to the libvirtd service : Cannot write data:
> Broken pipe

The code in question is used to communicate with *faaar* more than
just libvirtd, so such a change would be pretty misleading in
general.

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|