On 05/29/2012 05:42 PM, Doug Hellmann wrote: > IIRC, the meters discussed in the wiki [1] are supposed to show "delta" > values (usage since the last time an event was generated), although the > "Alternate Gauge Design" section discusses cumulative meters instead. The > libvirt pollsters we have now produce cumulative data, and it might be > complicated and error-prone to change them to compute the deltas internally > before generating events. On the other hand, some of the other counters may > be more complicated to generate as cumulative values. > > Rather than taking an either/or approach, I propose we document for each > counter whether it uses the delta or cumulative approach. The API server can > ask the meter plugin for that piece of information when calculating the > aggregate value so that the caller does not have to keep track of the rules > for each meter. > I tend to prefer using a gauge and I agree that documenting what was preferred (gauge or delta) for a given meter / counter is enough.
My 2ct ;-) -- Loïc Dachary Chief Research Officer // eNovance labs http://labs.enovance.com // ✉ l...@enovance.com ☎ +33 1 49 70 99 82 _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
