ALPS Environment Variables

The following environment variables modify the behavior of aprun:

APRUN_DEFAULT_MEMORY: Specifies the default per PE memory size. An explicit aprun -m value overrides this setting.
APRUN_XFER_LIMITS: Sets the rlimit() transfer limits for aprun. If this is set to a non-zero string, aprun will transfer the {get,set}rlimit() limits to apinit, which will use those limits on the compute nodes. If it is not set or set to 0, none of the limits will be transferred other than RLIMIT_CORE, RLIMIT_CPU, and possibly RLIMIT_RSS.
APRUN_SYNC_TTY: Sets synchronous tty for stdout and stderr output. Any non-zero value enables synchronous tty output. An explicit aprun -T value overrides this value.
PGAS_ERROR_FILE: Redirects error messages issued by the PGAS library (libpgas) to standard output stream when set to stdout. The default is stderr.
CRAY_CUDA_MPS: Overrides the site default for execution in simultaneous contexts on GPU-equipped nodes. Setting CRAY_CUDA_MPS to 1 or on will explicitly enable the CUDA proxy. To explicitly disable CUDA proxy, set to 0 or off. Debugging and use of performance tools to collect GPU statistics is only supported with the CUDA proxy disabled.
APRUN_PRINT_APID: When this variable is set and output is not suppressed with the -q option, the APID will be displayed upon launch and/or relaunch.

ALPS will pass values to the following application environment variable:

ALPS_APP_DEPTH: Reflects the aprun -d value as determined by apshepherd. The default is 1. The value can be different between compute nodes or sets of compute nodes when executing a MPMD job. In that case, an instance of apshepherd will determine the appropriate value locally for an executable.
ALPS_APP_ID: This value is set to the assigned application ID.
ALPS_APP_PE: This value is set to the ALPS-assigned PE for each application process launched by ALPS.