Andy Zhou <[email protected]> wrote on 09/11/2015 07:49:37 PM: > > >> On Wed, Nov 4, 2015 at 5:22 AM, Liran Schour <[email protected]> wrote: > >> > In order not to have 2 new monitor methods, maybe we should combine them > >> > into a single method. > >> > > >> > However, as I thought on this, monitor_cond without any conditions > >> > should > >> > not send any updates at all. A typical usage will be in OVN when > >> > ovn-controller will open a monitor_cond session with empty > >> > "where"condition > >> > array and when VMs are deployed on this host, it will add conditions by > >> > monitor_cond_change method and by that will get all the updates relevant > >> > to > >> > that specific host. > >> > > >> > As I see it, we have here 2 options: > >> > 1. monitor_cond without any "where" value will behave as the proposed > >> > monitor2 method - send updates upon all rows using update2 > >> > notifications. > >> > monitor_cond with "where" value that is an empty array will not send > >> > any > >> > updates at all till conditions are added by monitor_cond_change method. > >> > > >> This can work, but the API seems subtle. So I'd prefer to explore the > >> next option more. > >> > >> > 2. monitor_cond always sends updates. If there is no "where" value or it > >> > is > >> > an empty array, updates on all rows will be sent using update2 > >> > notifications. In this case a client will not be able to open a monitor > >> > session and expect no updates at all like written in the usage above. > >> > > >> > >> This seems natural. > >> > >> If no updates are expected at the beginning, could we come up with a > >> where condition that > >> will not generate any updates? Like "where false". > >> > > > > It can work if we can define "where" to be an array of <condition> and > > boolean values. For example: "where" : [false, <condition>*]. Since the > > monitor_cond will monitor any row that match at least one of the conditions, > > if we will have "where" : [false] no row will be monitored. > > This solution looks good to me. May be we can define <condition> as either > a 3-element array or a JSON boolean. For completeness, we can define > where : [] to be the same as where : [true] >
OK, I will work on a combined patch series based on your monitor2 branch with the Bug fix. However it seems that I will not be able to make it till after the OVS conference. _______________________________________________ dev mailing list [email protected] http://openvswitch.org/mailman/listinfo/dev
