[Planetlab-users] Sirius Calendar Service Not Functional

[Robert P Ricci]

The Sirius Calendar Service on PlanetLab is currently not functional.
Though Sirius is still accepting reservations, there is a bug that
prevents it from actually delivering the promised share of the CPU;
having a Sirius reservation currently makes no appreciable difference on
the amount of CPU a sliver gets on PlanetLab nodes.

The bug has been acknowledged by PlanetLab support, and I have been told
that it will not be fixed right away - a new version of the PlanetLab
software will be rolled out soon, so fixing bugs in the current version
is not a priority. I do not know for sure how long Sirius has been
broken, but I'm pretty sure it has been since at least December 19,
2006, when I first noticed the problem and reported it.

I discovered this while investigating why one of my applications did not
behave as expected with a Sirius reservation. I have since run large
experiments confirming the problem. If you're interested, I've put up a
page with more detail, including a graph demonstrating this issue, here:

    http://www.flux.utah.edu/users/ricci/sirius.html

The graph is somewhat interesting in its own right, as it shows the
distribution of available CPU across PlanetLab.

-- 
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| Robert P Ricci <ricci at cs.utah.edu> | <ricci at flux.utah.edu>
| Research Associate, University of Utah Flux Group
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