Oar is an open source batch scheduler which provides a simple and flexible exploitation of a cluster.
It manages resources of clusters as a traditional batch scheduler (as PBS / Torque / LSF / SGE / SLURM). In other words, it doesn't execute your job on the resources but manages them (reservation, acces granting) in order to allow you to connect to these resources and use them.
Its design is based on high level tools:
It is flexible enough to be suitable for production clusters and research experiments. It currently manages over than 5000 nodes and has executed more than 10 million jobs.
Like any other batch scheduler, OAR must become the users that submit jobs.
In OAR, security and user switching is managed by the “oardodo” command. It is a suid binary executable only by root and the oar group members. This is used to launch commands, scripts with the privileges of a particular user. When “oardodo” is called, it checks the value of the environment variable OARDO_BECOME_USER:
Here are the scripts/modules where “oardodo” is called and which user is used during this call:
For all these functions, the user used in the OARDO_BECOME_USER variable is the user that submits the job.