Hangovers from the Scary Grid

Grid software has a - not entirely undeserved - reputation for being complicated.

Things have improved but the NGS support staff still see code left over from the bad old Scary Grid.

Occasionally someone surfaces with a command like:

 
    globusrun -b -r ngs.site.ac.uk/jobmanager-pbs \
    -x '&(count=4)(jobtype=mpi)
       (environment=(NGSMODULES namd/64/2.7b1))
       (executable=/full/path/to/namd2)
       (arguments=/home/ngsxxxx/experiment/thing.in)
       (directory=/home/ngsxxxx/experiment)
       (stdout=/home/ngsxxxx/experiment/job.out)
       (stderr=/home/ngsxxxx/experiment/job.err)'

It works, but not even the most enthusiastic grid advocate could call it user friendly. It also needs a different invocation for every single site.

But things have changed, hopefully for the better...

• The grid software developers have produced less hairy commands. For example, there are globus-job-run and globus-job-submit commands that are simpler than globusrun.


• The NGS sites have agreed a common way for launching applications via scripts called /usr/ngs/SOMETHING that behave in the same way on all sites. This can replace the NGSMODULES environment trick used above.

The modern counterpart to the Scary Grid command would look like:

   globus-job-submit ngs.site.ac.uk/jobmanager-pbs \
       -np 4 -x '(jobtype=mpi)' -d '$(HOME)/experiment' \
       -stdout job.out -stderr job.err
          /usr/ngs/NAMD_2_7b1 namd2 thing.in

It might not be pretty but it is shorter, simpler and easier to convert to a different site.