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Restrictions are used to allow or restrict where jobs run, and are applied to both jobs and workers. Restrictions are based on cluster names, but differ from the clusters themselves by an important difference:
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Jobs and workers can belong to 1 and only 1 cluster, but can be restricted to none, 1, or several clusters |
This seems a bit hard to fathom, until you remember that a job has preferential priority on a worker whose cluster matches the job's cluster, but the job is free to run on any host in other clusters. The job's restriction value can be used to limit what other clusters the job could possibly run on.
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