Re: [HTCondor-users] Conditionally add default environment variables

[Todd L Miller <tlmiller@xxxxxxxxxxx>]

> What is the cleanest and most robust way for Condor 10.0.x on Linux to 
> add an environment variable assignment to a job's Environment ClassAd 
> attribute at job submission time conditional on there not already being 
> an assignment?

	As far as I know, the only way to do this is with job transforms.

> If there isn't a first class job classadd method to conditionally 
> manipulate the Environment attribute, does anyone have a working 
> JOB_TRANSFORM example that has all the right string escaping and error 
> handling?

	mergeEnvironment() will do what you want if you pass the default 
value(s) first.

> P.S. More generally, does Condor attempt any checks or control over the 
> plethora of environment variables that can be at variance with a job's 
> request_cpu value, e.g., OMP_NUM_THREADS, MPI_NUM_THREADS, 
> MKL_NUM_THREADS, OPENBLAS_NUM_THREADS, KMP_AFFINITY ... While Condor's 
> cgroup support is very helpful at preventing a job for using more than 
> it's fair share of cpu resources I am wondering about the converse where 
> one or more standard multi-threading libraries has gotten confused and 
> is limiting a job to use less than the allocated request_cpu assignment?

	HTCondor sets a number of these variables.  The list is in the 
config variable STARTER_NUM_THREADS_ENV_VARS.  HTCondor currently assumes 
that the user knows better and won't change variables set in the job's 
environment specification.  Note that KMP_AFFINITY appears to be special, 
because its value is not the number of threads to use.

- ToddM