On Feb 16, 2011, at 5:12 PM, Soren Hansen wrote: > * Whenever I ask something for information and I get out-of-date, > cached data back I feel like I'm back in 2003. And 2003 sucked, I > might add.
The other side of that coin was the implementation of pub/sub. New/deleted/changed instances would publish these events, and the zones would update accordingly. So there should be no time travel back to 2003. We had debated doing a regular polling to update, but pretty much everyone agreed that that would be especially sucky. > * Doesn't this caching strategy only help if people are asking for > the same stuff over and over? It doesn't sound very awesome if 100 > requests for new stuff coming in at roughly the same time causes a > request to be sent to every single compute node (or whereever the data > actually resides). I'm assuming breadth-first search here, of course. Well, if we get 100 requests to spin up instances, each zone will know which hosts or sub-zones it needs to query, which is the information being cached. If the request is to spin up a new instance, the multi-cluster/zone traversal part will be the fastest part of the determination. What will be more time-consuming is the scheduler logic to determine the host for that instance, and that isn't dependent on how zones are arranged or how information about them is tracked and updated. -- Ed Leafe _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp