----- Original Message ----- > From: "Livnat Peer" <lp...@redhat.com> > To: "Yair Zaslavsky" <yzasl...@redhat.com> > Cc: engine-devel@ovirt.org > Sent: Sunday, June 30, 2013 8:06:28 AM > Subject: Re: [Engine-devel] SSH Soft Fencing > > On 06/30/2013 05:46 AM, Yair Zaslavsky wrote: > > > > > > ----- Original Message ----- > >> From: "Barak Azulay" <bazu...@redhat.com> > >> To: "Martin Perina" <mper...@redhat.com> > >> Cc: "Yair Zaslavsky" <yzasl...@redhat.com>, engine-devel@ovirt.org, "Eli > >> Mesika" <emes...@redhat.com> > >> Sent: Thursday, June 27, 2013 8:31:35 PM > >> Subject: Re: SSH Soft Fencing > >> > >> > >> > >> ----- Original Message ----- > >>> From: "Eli Mesika" <emes...@redhat.com> > >>> To: "Yair Zaslavsky" <yzasl...@redhat.com> > >>> Cc: "Martin Perina" <mper...@redhat.com>, engine-devel@ovirt.org, "Barak > >>> Azulay" <bazu...@redhat.com> > >>> Sent: Thursday, June 27, 2013 5:55:29 PM > >>> Subject: Re: SSH Soft Fencing > >>> > >>> > >>> > >>> ----- Original Message ----- > >>>> From: "Yair Zaslavsky" <yzasl...@redhat.com> > >>>> To: "Eli Mesika" <emes...@redhat.com> > >>>> Cc: "Martin Perina" <mper...@redhat.com>, engine-devel@ovirt.org, "Barak > >>>> Azulay" <bazu...@redhat.com> > >>>> Sent: Thursday, June 27, 2013 5:43:17 PM > >>>> Subject: Re: SSH Soft Fencing > >>>> > >>>> > >>>> > >>>> ----- Original Message ----- > >>>>> From: "Eli Mesika" <emes...@redhat.com> > >>>>> To: "Martin Perina" <mper...@redhat.com> > >>>>> Cc: engine-devel@ovirt.org, "Yair Zaslavsky" <yzasl...@redhat.com>, > >>>>> "Barak > >>>>> Azulay" <bazu...@redhat.com> > >>>>> Sent: Thursday, June 27, 2013 3:48:39 PM > >>>>> Subject: Re: SSH Soft Fencing > >>>>> > >>>>> > >>>>> > >>>>> ----- Original Message ----- > >>>>>> From: "Martin Perina" <mper...@redhat.com> > >>>>>> To: engine-devel@ovirt.org > >>>>>> Cc: "Yair Zaslavsky" <yzasl...@redhat.com>, "Barak Azulay" > >>>>>> <bazu...@redhat.com>, "Eli Mesika" <emes...@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) > > > > +1 on configuration. > > Configuration must reside at host-related entities (i.e - VdsStatic). > > > > Yair > > > > Why would a user like to avoid fencing VDSM when host becomes > non-responsive? > > I think that adding another configuration option is cumbersome with no > real value.
I totally agree with Livnat here , restarting vdsm may resolve problems and is much less brutal that host restart, should be implemented without any configuration IMHO > > Livnat > > >> > >> > >> > >>> > >>>> > >>>>> > >>>>>> > >>>>>> 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 > >>>>>> > >>>>> > >>>> > >>> > >> > > _______________________________________________ > > Engine-devel mailing list > > Engine-devel@ovirt.org > > http://lists.ovirt.org/mailman/listinfo/engine-devel > > > > _______________________________________________ > Engine-devel mailing list > Engine-devel@ovirt.org > http://lists.ovirt.org/mailman/listinfo/engine-devel > _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel
