10:57 p.m.
----- Original Message -----
From: "Barak Azulay" <bazulay(a)redhat.com>
To: "Martin Perina" <mperina(a)redhat.com>
Cc: "Yair Zaslavsky" <yzaslavs(a)redhat.com>, engine-devel(a)ovirt.org,
"Eli Mesika" <emesika(a)redhat.com>
Sent: Sunday, June 30, 2013 7:35:22 PM
Subject: Re: SSH Soft Fencing
----- Original Message -----
> From: "Barak Azulay" <bazulay(a)redhat.com>
> To: "Martin Perina" <mperina(a)redhat.com>
> Cc: "Yair Zaslavsky" <yzaslavs(a)redhat.com>, engine-devel(a)ovirt.org,
"Eli
> Mesika" <emesika(a)redhat.com>
> Sent: Thursday, June 27, 2013 8:31:35 PM
> Subject: Re: SSH Soft Fencing
>
>
>
> ----- 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 ?
Yes, I think we should limit that 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.
We can keep this internal and not expose it to the user, just implement explicitly in non
responding treatment
Martin ? Eli? Yair?
Can you please refer to the issue above ?
>
> Thoughts ?
>
>
>
> > > >
> > > > >
> > > > >
> > > > > Martin Perina
> > > > >
> > > >
> > >
> >
>