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

[Thierry Parmentelat]

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