[Planetlab-devel] cache-based federation and slice attributes

[Tony Mack]

We need to agree on a set of attributes that we will pass between peers 
and define a way to translate attributes between peers.
Once we've done that we could limit what gets passed to NM, or make NM 
decide whats it should accept from each slice.


Larry Peterson wrote:
> How do we go about selecting attributes, on an as-needed basis, that
> we need to translate across federation boundaries. I agree that parsing
> slices.xml by hand sucks.
>
> Larry
>
> On Jul 17, 2007, at 11:27 AM, Thierry Parmentelat wrote:
>
>> Hello everyone
>>
>> I'd like to come back on an issue that I'm having with the federation 
>> code
>> I've tried to make that point already but am not sure I did, so just 
>> so everyone is on the same page:
>>
>> To summarize the issue:
>> * some/most slices, like comon, need slice attributes to operate 
>> correctly (e.g. proper privileges)
>> * the federation code does *not* cache this at the moment, the 
>> rationale being that granting such privileges should be an explicit 
>> decision on the foreign plc end (e.g. for comon, we at planet-lab.eu 
>> should set those slice attributes for the nodes that we run)
>> * but since the slice attributes are not cached *at all*, that 
>> foreign plc has no clue what is actually needed.
>>
>>
>> As a quick and dirty workaround, so we can run planet-lab.eu 
>> smoothly, I went into a gory parsing of slices.xml and eventually 
>> digged my way; I hope to have comon show up shortly; other slices may 
>> need to ask us to set this sort of things.
>>
>>
>> However this of course sucks. The point I tried to make is that the 
>> current data model in myplc needs to be altered.
>> IMO there should be a clear distinction between, on the one hand what 
>> a slice requested, and on the other hand what the hosting myplc has 
>> granted. The former being, if I got it right, a function of the SA 
>> side of myplc, and the latter a function of the MA side.
>>
>>
>> As a final note. The idea that was presented by Stephen in Warsaw, 
>> about using a 'delegation' slice on foreign nodes as a 'service 
>> creation handle' looks real nice, and the more I think about it the 
>> more I like this idea; it would clearly have a simpler impact on the 
>> data model than the current cache-based federation scheme had had, 
>> and would make the separation between MA and SA much more natural. It 
>> would be however, mostly orthogonal with the issue I described above; 
>> IMHO.
>>
>> -- Thierry
>>
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>
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