Ulf Wendel napsal(a): > Jan, > > Thanks for getting back to me. > > Am 10.04.2013 15:02, schrieb Jan Friesse: >> Ulf, >> >> Ulf Wendel napsal(a): >>> Dear experts, >>> >>> I browsed parts of the documentation and wiki but missed to understand a >>> basic property thus far. I understand corosync constitutes a ring of >>> executive daemons with application clients connected to the executive >>> daemons. >>> >>> - How many executive daemons can there be? >> >> Officially supported are 16 nodes, but success are reported for 32 and >> even 64 nodes. 64 nodes is maximum (I'm really not sure exactly WHY this >> limit exists) > > Great, that is well within the numbers I am looking for. > >>> - Can executive daemon be added and removed online? >>> >> >> Sure >> >>> I assume the number of application clients is limited by practical >>> matters only, for example, time required to reach out to all connected >>> application clients shoud be considered. Clients can connect and >>> disconnect without bringing the cluster down. >>> >>> But, what if one wants to add executives? Will this require >>> reconfiguration of all other executives in the cluster, will the cluster >>> go down or experience a view change only... >>> >> >> As long as you are using udp (multicast) nothing is needed. For udpu >> (unicast), you must issue commands described in cmap_keys man page. > > > Excellent! > > I've had only a quick look at spread.org but it seemed to me that > spread.org required updating and deploying the config file manually. As > I understand you, config deployment is an integral part of the corosync > API and can be done at runtime. Actually it's only partly true. You still need to deploy configuration file (config deployment is for sure one of things which may be so nice to have and there were ideas of using DNS for that), but when using multicast, you can set mcast bind address to network address (so let's say network is 192.168.1.0/24 and n1 is 192.168.1.1, n2 is 192.168.1.2, ..., you can set 192.168.1.0 as bindaddr in corosync.conf) and don't need to configure each node in file on each node (as in spread toolkit). Honza > > Thanks, > Ulf > _______________________________________________ discuss mailing list discuss@xxxxxxxxxxxx http://lists.corosync.org/mailman/listinfo/discuss
