[occi-wg] Events ?

[Gary Mazz]

You've got it...

I do like the idea of long life messages and events. I think events will 
be important just from the perspective of well know programming 
practices. I personally don't see unix signals going away for a long 
while. 

Resources can change states for one reason or another. Networking and 
storage (another network) are often victims of accidental switch 
reconfigurations resulting in loss of connectivity to endpoints.

Configuration changes to resources outside the scope of the "active 
state" in the "life cycle model" may need to be logged or corrective 
action may be engaged.

Long life remote service dependencies are another area where events may 
be appropriate. Normally, I would suggest the applications handle 
occurrences between parties, but with migration as a normal 
circumstance, it may be out of control and scope of the parties. Either 
the infrastructure will handle a "pause for migration" event or the 
container will tell the app which will tell the other party. Queuing (a 
bridge) may be a way to avoid the issue as long as the service 
parameters are not violated. But it may be out of scope for 
interoperability.

Security or privilege revocation is another area. Hard execution breaks 
due to user or admin control is still another area. 

Polling may be inappropriate in many cases, driving up CPU loads and 
network bandwidth consumption.

I'll get them on the wiki in the later AM... I'm gmt -7

-gary

Sam Johnston wrote:
> On Mon, May 18, 2009 at 7:55 PM, Gary Mazz <garymazzaferro at gmail.com 
> <mailto:garymazzaferro at gmail.com>> wrote:
>
>     Hi,
>
>      From the current discussions, there has been no mention of
>     events. Will
>     the occi support events ? What will the model look like ?
>
>
> This is something I had thought about a little but not considered a 
> focus point for us. I did however consider the possibility of OCCI 
> messages being long lived in that they can be queued and passed over 
> transports like XMPP (this was one of a number of potential use cases 
> for signatures).
>
> The interest in doing this would be, for example, a client that has 
> rendered a number of resources and wants to know about state changes 
> and the like. They would just need to subscribe to the resource and 
> when the state changes they would be sent the updated entry. Similarly 
> an management system could ask for regular updates of e.g. performance 
> monitor counters.
>
> Does this sound adequate for your needs or do you have use case(s) 
> that require more - and if so, why aren't they in the wiki ;)
>
> Sam
>