[GridSim-developers] Problems with Gridlet cancellation and some questions

[Marcos D. de A. <ma...@cs...>]

Dear All,

Firstly, I would like to know if someone has used the gridlet
cancellation capabilities of GridSim? Secondly, I would like to
mention a few things about the gridletCancel() methods in the
allocation policy classes. It seems that at no point the Gridlet
status is changed to CANCELED. The method sendCancelGridlet() of the
AllocPolicy class contains:

[=85]
long gridletSize =3D 0;
        if (gl !=3D null) {
            gridletSize =3D gl.getGridletOutputSize();
        }
[=85]
super.sim_schedule( outputPort_, GridSimTags.SCHEDULE_NOW, tag,
                            new IO_data(gl, gridletSize, destId) );

Which means that the status of the Gridlet is not changed and that the
gridlet is sent back to the user when cancelled. The number of bytes
transmitted is in fact the size of the output files. That means that
even if the Gridlet is cancelled, it is actually not cancelled and the
number of bytes sent back to the sender is equals to the number of
bytes that would be sent if the Gridlet had been completed.

My questions are regarding the advance reservation features. I know
that GridSim uses a resource calendar and some estimates of local
load. It uses this to get information about days of the week and
respective local load. However, I am wondering and intrigued, why do
we need time zones particularly in advance reservations? If this is a
policy related issue, for example, a resource provider accepts advance
reservations on Mondays? Still, I am not sure whether we need the time
zone information in classes like ARObject. GridSim, as any event
driven simulator uses a simulation clock. All entities schedule events
based on this clock. Therefore, why do we need to convert times
between time zones? I would be grateful if anybody could explain to me
the design decisions that have led to the adoption of time zones in
the advance reservation framework.

Regards,

Marcos


--=20
Marcos Dias de Assuncao
Grid Computing and Distributed Systems (GRIDS) Laboratory
Department of Computer Science and Software Engineering
The University of Melbourne, Australia
Email: ma...@cs...