Re: [Engine-devel] SSH Soft Fencing
----- Original Message -----
From: "Yair Zaslavsky" <yzaslavs(a)redhat.com>
To: "Eli Mesika" <emesika(a)redhat.com>
Cc: "Martin Perina" <mperina(a)redhat.com>, engine-devel(a)ovirt.org,
"Barak Azulay" <bazulay(a)redhat.com>
Sent: Thursday, June 27, 2013 5:43:17 PM
Subject: Re: SSH Soft Fencing
----- Original Message -----
> From: "Eli Mesika" <emesika(a)redhat.com>
> To: "Martin Perina" <mperina(a)redhat.com>
> Cc: engine-devel(a)ovirt.org, "Yair Zaslavsky" <yzaslavs(a)redhat.com>,
"Barak
> Azulay" <bazulay(a)redhat.com>
> Sent: Thursday, June 27, 2013 3:48:39 PM
> Subject: Re: SSH Soft Fencing
>
>
>
> ----- Original Message -----
> > From: "Martin Perina" <mperina(a)redhat.com>
> > To: engine-devel(a)ovirt.org
> > Cc: "Yair Zaslavsky" <yzaslavs(a)redhat.com>, "Barak
Azulay"
> > <bazulay(a)redhat.com>, "Eli Mesika" <emesika(a)redhat.com>
> > Sent: Thursday, June 27, 2013 1:51:06 PM
> > Subject: SSH Soft Fencing
> >
> > Hi,
> >
> > SSH Soft Fencing is a new feature for 3.3 and it tries to restart VDSM
> > using SSH connection on non responsive hosts prior to real fencing.
> > More info can be found at
> >
> > http://www.ovirt.org/Automatic_Fencing#Automatic_Fencing_in_oVirt_3.3
> >
> > In current SSH Soft Fencing implementation the restart VDSM using SSH
> > command is part of standard fencing implementation in
> > VdsNotRespondingTreatmentCommand. But this command is executed only
> > if a host has a valid PM configuration. If host doesn't have a valid
> > PM configuration, the execution of the command is disabled and host
> > state is change to Non Responsive.
> >
> > So my question are:
> >
> > 1) Should SSH Soft Fencing be executed on hosts without valid PM
> > configuration?
>
> I think that the answer should be yes. The vdsm restart will solve most of
> problems , so why not using it whether a PM agent is defined or not.
I agree.
I would like to say that I also don't like the fact that
VdsNotRespondingTreatment extends RestartVdsCommand.
One should ask if "non responding treatment is a restart vds operation" or
maybe RestartVdsCommand is just a step in the non responding treatment
(inheritance vs containment/delegation).
I think that VdsNotRespodingTreatment should delegate the call to
RestartVdsCommand as the 2nd step after issuing the Soft Fencing command.
Thoughts anyone?
That would be a nice and needed re-factoring
>
> >
> > 2) Should VDSM restart using SSH command be reimplemented
> > as standalone command to be usable also in other parts of engine?
> > If 1) is true, I think it will have to be done anyway.
I agree here.
>
> +1
>
> >
> >
> > Martin Perina
> >
>