[ovirt-devel] [vdsm] Connection refused when talking to jsonrpc

[Francesco Romani]

----- Original Message -----
> From: "Piotr Kliczewski" <pkliczew at redhat.com>
> To: "Martin Sivak" <msivak at redhat.com>
> Cc: "Michal Skrivanek" <michal.skrivanek at redhat.com>, "Francesco Romani" <fromani at redhat.com>, "Shira Maximov"
> <mshira at redhat.com>, "devel" <devel at ovirt.org>
> Sent: Wednesday, November 9, 2016 9:54:02 AM
> Subject: Re: [ovirt-devel] [vdsm] Connection refused when talking to jsonrpc
> 
> On Wed, Nov 9, 2016 at 9:48 AM, Martin Sivak <msivak at redhat.com> wrote:
> 
> > > Isn’t the most likely cause by far a simple startup delay? We do open
> > the listener “soon” and responds with code 99, but it’s still not instant
> > of course
> >
> > That is possible of course and we handle those "errors" just fine. But
> > connection refused never happened with xmlrpc. It might have been
> > luck, but it always worked there :)
> >
> >
> There is no difference how we open listening socket (it is used by both
> protocols) and I have seen the engine attempting to connect using both
> protocols
> before the socket was open. What is the time difference that you see?

Not sure I reproduced correctly, but it seems a race on startup.
I got the same error on my box, and here it happens if mom tries to connect
to the unix socket /var/run/vdsm/mom-vdsm.sock *before* that Vdsm creates it.
Once vdsmd succesfully starts, a restart of mom-vdsm seems to fix all the issues.

I'm not sure yet if that's all of it and how to handle with systemd dependencies.
Perhaps Nir's suggestion past in the thread to notify systemd is a good first step
in the right direction.

HTH,

-- 
Francesco Romani
Red Hat Engineering Virtualization R & D
Phone: 8261328
IRC: fromani