This was a great thread. :) It also made me realize we don't document cluster-name in Pacemaker Explained, so I'll do that for the next release.
On Thu, 2019-03-28 at 08:30 +0000, Christine Caulfield wrote: > On 26/03/2019 20:12, Brian Reichert wrote: > > This will sound like a dumb question: > > > > The manpage for pcs(8) implies that to set up a cluster, one needs > > to provide a name. > > > > Why do clusters have names? > > > > Is there a use case wherein there would be multiple clusters > > visible > > in an administrative UI, such that they'd need to be > > differentiated? > > > > > Alongside the current usage there's some history here. Originally > (when > cman was in the kernel) the name was used to get the correct > information > from the centralised cluster configuration daemon (ccsd). > > After that it got used as a hash to generate a cluster_id for > clusters > that might be on the same network (cluster_id as a number was also > allowed, but as name was already a field it seemed sensible to keep > using it). The hashed cluster_id was included in the protocol so that > clashing clusters would ignore each other's messages. In a later > revision the cluster name was also hashed to generate a very > primitive > encryption key for openais if one was not provided. This was, again, > more to provide isolation than actual security. > > Of course it's used for none of those things now, but that's where it > came from originally :) > > Chrissie -- Ken Gaillot <[email protected]> _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
