What happens if a ZoneManager process dies? When the ZoneManager restarts, the compute nodes will send their attributes to the newly restarted ZoneManager and the in-memory list of attributes will be reconstructed, right? The only downside to this approach is the (probably short) time that it takes for the restarted ZoneManager to reconstruct its in-memory db of host attributes.
As an unrelated side note, the folks over in Hadoop land use this sort of 'in-memory data-structures fed by heartbeats' approach with much success. - Jagane ________________________________________ From: [email protected] [[email protected]] On Behalf Of Sandy Walsh [[email protected]] Sent: Friday, April 15, 2011 2:24 PM To: Jay Pipes; Ed Leafe Cc: Mark Washenberger; [email protected] Subject: Re: [Openstack] distributed and heterogeneous schedulers Each update from the services are atomic updates ... fully self contained. Why does this need to be in a persistent store? -S ________________________________________ From: Jay Pipes [[email protected]] > you still need a persistent data store for attributes of the host. Just > because you > store a cached in-memory copy of instance attributes, doesn't mean you > don't need a persistent data store. You still need a persistent data > store regardless of whether it's a database table, a FLAG value, or > /proc/cpuinfo. _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : [email protected] Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : [email protected] Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
