Re: [Condor-users] Looking for something like CpuBusy for Disk

[Lans Carstensen <Lans.Carstensen@xxxxxxxxxxxxxx>]

Greetings!  Ian Chesal wrote:
> On Fri, Sep 3, 2010 at 2:13 PM, Diane Trout <diane@xxxxxxxxxxx 
> <mailto:diane@xxxxxxxxxxx>> wrote:
>
>     Can you define an expression that queries a different machines
>     attributes?
>
>
> Not from within a Job or Machine's ad. During matchmaking you only have 
> access to the machine's ad and the job's ad. You could write a Startd 
> cron that queries your filer for that value and imports it in to the 
> machine's ad.
>  
>
>     For example:
>
>     The main file server publishes an attribute
>     PercentUtilization.Partition1
>
>     Can another machine query the attribute for instance
>     FileServer.PercentUtilization.Partion1? Or would I need to use an
>     external script to push the attribute into each machines local ClassAd?
>
>
> You'd need to pull it in to the startd's ad on the machine where you're 
> trying to decide if a job should run or not using a startd cron.
>
> But: seriously cool idea to be able to reference other machine's ads. 
> Especially if the other ad is for something like a common resource, a 
> filer in your case. Something for Miron and his crew to consider I 
> suppose...

The seriously cool way would be to standardize a global resource classad 
type and allow for expression logic to have a way to directly address 
all resource ads that are deemed to apply to a particular slot and job.

This reminds me that the other way we address the common use case for 
this class of problem is with concurrency limits on jobs - but that 
doesn't handle slot-level use cases, only job-level ones.

Partitionable slot-level resource/concurrency limits would be a useful 
addition towards that goal.  Then you might want to apply some feedback 
mechanism to make the upper bound of that partitionable slot dynamic 
based upon some business logic (like a global resource classad).

-- Lans Carstensen