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

[Michal Skrivanek]

> On 9 Nov 2016, at 09:57, Francesco Romani <fromani at redhat.com> wrote:
> 
> 
> 
> ----- 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.

not sure
we would need to wait for recovery to finish if you want to be really nice to “dumb” clients
that would take too long though

I think mom needs a fix in addition anyway

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