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 _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
