PBS Professional is a workload manager and job scheduler for high-performance computing (HPC) clusters and supercomputers. It has been architected to meet the needs of companies looking to prepare for the move to exascale. Features and capabilities include a comprehensive health check framework that monitors users’ health check script behavior — either checks run or node is marked down — and scalability to millions of jobs per day, which has been tested to more than 50,000 nodes. Fine-grained targeting for preemption is configurable at the queue level (admin controlled), and general fairshare formula enables accruals per-Q, license sharing, time-of-day, power use, and combinations of these. Custom resources can be created directly using qmgr, without the need to restart the server, and long job and reservation names are supported.