Hi Jason, On Jan 13, 2010, at 3:52 PM, Jason Zurawski wrote:
Hi Candido;
- I think the structure of namespace could be explained
The original thinking was the NM-WG document, "An Extensible Schema for Network Measurement and Performance Data", would contain the entire explanation of namespaces (the idea itself coming from another OGF WG). Any future documents from related projects (NMC, NML, others?) would reference this and only note caveats to the original rule. The NM- WG doc is here:
https://forge.gridforum.org/sf/go/doc15649?nav=1
And I think namespaces are in section 4. Does everyone think this is sufficient, or should we consider other options? The explanation of namespaces is clear to me. But I have a comment about EventTypes. In 3.1 and in 7.1 I understand that the EventyType in a metadata MUST appear only one time. But in the last example in 5.4 is showing two event types and it says that those "MAY NOT appear". I think it should say "MUST NOT appear" unless there are cases where it makes sense to allow two or more event types. Also, the section 5 was a little confuse to me. I see that metadata can be merged but I don't get how they should be merged. I read it again and I'll send comments and ideas about this.
I am a little lost in your explanation, there is not a section 3.1 in the NMC Base document, are you referring to the NM-WG document instead?
Yep, I'm sorry about this confusion. I'd printed both document and I brought the wrong one to home :(
Let me try to clear up the eventType explanation anyway:
- multiple eventTypes in a single metadata are possible and common, e.g. something from the 'characteristic' namespace and the 'tool' namespace. An example would be SNMP data:
http://ggf.org/ns/nmwg/tools/snmp/2.0 http://ggf.org/ns/nmwg/characteristic/utilization/2.0
Yes, I think it's very well explained in the nmc-base document. Maybe we can add a row in tables specifying if the element is multiple or not...
- The example you are referring to (page 30 in the nmc doc I think?) is poorly worded. The situation I was trying to describe is merging metadata where the eventTypes are not compatible. In this case 'errors' is very different than 'utilization' and shouldn't be merged. I will place a note in this to clear this up down the road.
Does this help a little bit?
Chaining is a hard concept, and this represents my view of how it works. I may have some details wrong. I think that Martin, Jeff, and Roman should carefully read these sections to check my accuracy in describing things.
I think it's clearer in the nmc-base document. However, if I've understood it well, the document explains some general rules about chaining but it's the service which decides how it will do it, isn't it? So, there isn't any standard (or automatic) way of doing? Also, there is a typo in the first line in 7.1.5.1. I cannot see the the whole value of the eventType. And about the event types hierarchy, I prefer the 2nd option. Regards
Thanks;
-jason
-- Cándido Rodríguez Montes E-mail: candido.rodriguez@rediris.es Middleware warrior Tel:+34 955 05 66 13 Red.ES/RedIRIS Edificio CICA Avenida Reina Mercedes, s/n 41012 Sevilla SPAIN