LHC Computer Grid - Rollout
> [mailto:[log in to unmask]] On Behalf Of Rod Walker said:
> Only the scheduler knows which job will start next so only
> the scheduler can give the estimated response time.
In general even the scheduler doesn't know in advance when jobs will
start - and it certainly doesn't know when they will finish!
> Maui provides showstart [JOB]
> http://www.clusterresources.com/products/maui/docs/commands/sh
> owstart.shtml
The disclaimers on that page suggest that in general it won't give a
useful answer. Also it says that it calculates the earliest possible
start time, which isn't really what you want. I regularly argue that you
should err on the side of pessimism - better for a site to repel jobs it
could run than attract jobs it can't.
Another point is that the values published across sites need to be
reasonably compatible, so methods for different batch systems which give
substantially different answers aren't a good idea. A simple example of
that is that early in EDG the BQS info provider at Lyon always published
an ETT of at least 120 seconds because it took that long to start any
job, whereas PBS published zero (and still does) for empty queues. The
result was that Lyon got no jobs until every other sites was full ...
Stephen
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