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! > > 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? >
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 _______________________________________________ Openais mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/openais
