[Swift-devel] swift changing walltime of prews-gram jobs

[Ben Clifford]

Using coasters will cause job submissions with different walltimes than 
your individual swift-level jobs.

Coaster workers get submitted with a longer walltime than the jobs you are 
trying to send through. This is intended to result in coaster workers that 
will run long enough to run many jobs.

At the moment, this is not very configurable. In the source code,

provider-coaster//src/org/globus/cog/abstraction/coaster/service/job/manager/WorkerManager.java

contains these fragments:

    public static final Seconds TIME_RESERVE = new Seconds(60);
    public static final int OVERALLOCATION_FACTOR = 10;
    startWorker(new Seconds(req.maxWallTime.getSeconds())
                            .multiply(OVERALLOCATION_FACTOR)
                            .add(TIME_RESERVE), req.prototype);


so whatever your maxwalltime is, you'll get coaster workers submitted with 
ten times that plus one minute.

The coaster workers don't enforce job maxwalltimes, so you can work around 
this by making the job maxwalltimes small enough so that 10*that+60s fits 
inside the queue maximum wall time, even if that is actually too small for 
your jobs.

You should see the same behaviour using local:pbs, which will use direct 
PBS submission instead of GRAM; but you don't. That is an inconsistency 
that suggests something is not right. My initial suspicion would be that 
the cog PBS provider is not correctly passing either the walltime or queue 
parameters. I will investigate this.

Probably coasters should get another configuration option to allow the 
worker wall time to be more explicitly set, separately from job execution 
wall times - that makes sense for sites where parameters such as queue 
limits are well known by the user.

Thanks for testing 0.8rc1.

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