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Interactive jobs

Interactive MPI programs are executed applying the following steps (example for the default medium partition):

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For using compute resources interactively, e.g. to follow the execution of MPI programs, the following steps are required. Note that non-interactive batch jobs via job scripts (see below) are the primary way of using the compute resources.

1. A resource allocation for interactive usage has to be requested first with the salloc --interactive command which should also include your resource requirements.
2. When salloc successfully allocated the requested resources and when working at the Göttingen complex (Emmy), you are automatically logged in at one of the allocated compute nodes. For Berlin (Lise), you have to issue an additional srun command to work one of the allocated nodes (see example below) if you want to work on the compute node.
3. Afterwards, srun or MPI launch commands, like mpirun or mpiexec, can be used to start parallel programs (see according user guides)

blogin1: ~ >$ srunsalloc -t 00:10:00 -p medium40standard96:test -N2 --tasks-per-node 24
salloc: Granted job allocation [...]
salloc: Waiting for resource configuration
salloc: Nodes bcn[1001,1003] are ready for job
# To get a shell on one of the allocated nodes at the Berlin complex/Lise (not required for Göttingen/Emmy)
blogin1 ~ $ srun --pty --interactive bash
bash-4.2$ mpirun hello_world >> hello_world.out
bash-4.2$ exit
blogin1:~ >  --preserve-env ${SHELL}
bcn1001 ~ $ srun hostname | sort | uniq -c
     24 bcn1001
     24 bcn1003
bcn1001 ~ $ exit
# Exit a second time for Berlin/Lise 
blogin1:~ > exit
salloc: Relinquishing job allocation [...]

Job scripts

Please go to our webpage MPI, OpenMP start Guide for more details about job scripts. For introduction, standard batch system jobs are executed applying the following steps:

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