On 14/07/10 17:47, Sampathkumar, Kishore wrote: > Christine Caulfield wrote . . . > > +On 13/07/10 15:19, Sampathkumar, Kishore wrote: > > +> I had another follow-up question. > > +> > > +> Without any quorum provider (say, testquorum, votequorum), the cluster > > +> is always is ?quorate?. I observe that this is the ?default? behavior. > > +> > > +> Now, when a quorum provider like testquorum sets the quorum to > > +> ?inquorate? (see below), what is the expected behavior? Do all the > > +> MCAST messages sent by/to this Node (on which quorum is ?inquorate?) > fail? > > +> > > +> As an aside, ?testquorum? seems to set only the local node quorum to > > +> ?inquorate?. The other node is unaffected! > > +>
Yes. if there is no quorum provider loaded then you will always have quorum. That's a default setting to stop things breaking really. It's not meant to be very useful! Testquorum is a test program. it does what it does. It's not mean to be used to drive a cluster... Chrissie > > +> - Kishore > > +> > > +> *From:* Sampathkumar, Kishore > > +> *Sent:* Tuesday, July 13, 2010 10:49 AM > > +> *To:* [email protected] > > +> *Subject:* What does the quorum service really do when it has no > > +> linkage to groups/nodes? > > +> > > +> The following are the entries I have made towards the end of > > +> /etc/corosync/corosync.conf: > > +> > > +> service { > > +> > > +> name: corosync_quorum > > +> > > +> ver: 0 > > +> > > +> } > > +> > > +> quorum { > > +> > > +> provider: testquorum > > +> > > +> } > > +> > > +> I then ran the following: > > +> > > +> [r...@localhost tools]# ./corosync-quorumtool -s > > +> > > +> Version: 1.2.3 > > +> > > +> Nodes: 0 > > +> > > +> Ring ID: 0 > > +> > > +> Quorum type: testquorum > > +> > > +> Quorate: No > > +> > > +> [r...@localhost tools]# ./corosync-cpgtool > > +> > > +> Group Name PID Node ID > > +> > > +> CPG1\x00 > > +> > > +> 25398 846833856 (192.168.121.50) > > +> > > +> 2302 1064937664 (192.168.121.63) > > +> > > +> I want to tie the quorum to a specific ?group? (in the above example > > +> CPG1). How do I do that? The API?s for quorum declared in > > +> include/corosync/quorum.h do not have any reference to any CPG. > > +> > > +> So, what is the quorum expected to represent then? Quorum of Nodes in > > +> Ring 0? If so, how? How does a programmer ?use? the quorum API?s then? > > +> > > + > > +Quorum is a property of the whole cluster. Some internal corosync services > > +check it, most don't. That's because they need to keep working during a > quorum > > +transition. It's the job of applications what need to know quorum to > check it > > +for themselves. > > + > > +The quorum API is quite basic, it just tells you whether the cluster has > > +quorum or not, and a list of nodeids. quorum providers (like > votequorum) have > > +more API calls layered onto that to provide extra information as to how > quorum > > +has been calculated. An application that just needs to know quorum state > > +should use the basic quorum_ API calls so that it will work regardless of > > +which quorum provider is loaded. > > + > > +testquorum is a test module ... it's not meant to be used in production :-) > > + > > +Chrissie > > Today, the quorum API reports that the cluster has quorum, but the list of > > nodeids is empty. Is this what is expected when there are no quorum > providers? > > If I include votequorum as the quorum provider, but don't use any of the > API's > > provided by votequorum, will I see the quorum state as well as the list of > > nodeids that form the quorum in the cluster? > > My point is, when we say the cluster has quorum, should one obtain the nodes > > that form the quorum from the quorum API's? If not, how else? > > Thanks, > > - Kishore > > *From:* Sampathkumar, Kishore > *Sent:* Tuesday, July 13, 2010 7:50 PM > *To:* '[email protected]' > *Subject:* RE: What does the quorum service really do when it has no > linkage to groups/nodes? > > I had another follow-up question. > > Without any quorum provider (say, testquorum, votequorum), the cluster > is always is “quorate”. I observe that this is the “default” behavior. > > Now, when a quorum provider like testquorum sets the quorum to > “inquorate” (see below), what is the expected behavior? Do all the MCAST > messages sent by/to this Node (on which quorum is “inquorate”) fail? > > As an aside, “testquorum” seems to set only the local node quorum to > “inquorate”. The other node is unaffected! > > Thanks, > > - Kishore > > *From:* Sampathkumar, Kishore > *Sent:* Tuesday, July 13, 2010 10:49 AM > *To:* [email protected] > *Subject:* What does the quorum service really do when it has no linkage > to groups/nodes? > > The following are the entries I have made towards the end of > /etc/corosync/corosync.conf: > > service { > > name: corosync_quorum > > ver: 0 > > } > > quorum { > > provider: testquorum > > } > > I then ran the following: > > [r...@localhost tools]# ./corosync-quorumtool -s > > Version: 1.2.3 > > Nodes: 0 > > Ring ID: 0 > > Quorum type: testquorum > > Quorate: No > > [r...@localhost tools]# ./corosync-cpgtool > > Group Name PID Node ID > > CPG1\x00 > > 25398 846833856 (192.168.121.50) > > 2302 1064937664 (192.168.121.63) > > I want to tie the quorum to a specific “group” (in the above example > CPG1). How do I do that? The API’s for quorum declared in > include/corosync/quorum.h do not have any reference to any CPG. > > So, what is the quorum expected to represent then? Quorum of Nodes in > Ring 0? If so, how? How does a programmer “use” the quorum API’s then? > > Thanks, > > - Kishore > > > > _______________________________________________ > Openais mailing list > [email protected] > https://lists.linux-foundation.org/mailman/listinfo/openais _______________________________________________ Openais mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/openais
