8:31 p.m.
----- Original Message -----
From: "Eli Mesika" <emesika(a)redhat.com>
To: "Yair Zaslavsky" <yzaslavs(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 5:55:29 PM
Subject: Re: 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
I would say yes - but would add it only with appropriate configuration
(enableAutoSoftVdsmRestartWhenNoPMAvailable .... I hate the name)
>
> >
> > >
> > > 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
On one hand it makes sense, but I have several questions on the above:
- Who do we think may want to use such a command ?
- Should (or even can) we limit the use of such command to noneResponsiveTreatment ?
Having general commands available to all code when there is only one specific case we are
using it might be a bit riskey,
Especially when we talk about restarting something.
Thoughts ?
> >
> > >
> > >
> > > Martin Perina
> > >
> >
>