[Swift-devel] Intentional change to behavior of high/lowOverAllocation parameter?

[Michael Wilde]

Mihael,

For quite a while now I have been telling people to set the coaster parameters lowOverAllocation and highOverAllocation to 100 to force coasters to set the time allocation of every block to maxTime. (This was based on your advice around the time we started running on Beagle, to enable the user to force a specific and constant PBS job walltime).

Cog rev 3225 seems to have introduced a change that insists that these two parameters have a value < 1.0:
+        checkLessThan("lowOverallocation", 1);
+        checkLessThan("highOverallocation", 1);

If not, the job fails with an exception:

org.globus.cog.abstraction.impl.common.task.TaskSubmissionException: lowOverallocation must be < 1.0 (currently 100.0)

In addition, when I *do* set both parameters to 0.9999 (to try to achieve the same effect as they gave before) then I encounter the phenomenon of coasters starting with a ~10 minute walltime, but my app job doesnt seem to "fit" into the coaster block, and hence Swift just idles making no progress.  If I try to reduce my app maxwalltime, then walltime of the PBS job is lowered, but the app job still doesnt "fit" and never gets run.  I can send a log if the cause for this not obvious to you.

Can you explain what the intended behavior is here, and whether you think the new check (circa Aug 7) introduced a bug?

Thanks,

- Mike