In case EDA people search those key words, I might help to answer the questions.
Since 2006, we use below concepts:
free_slot = total compute node cpu number in cluster
calibre_slot = calibre remote cpu number
tflex_slot = brion tflex remote leaf cpu number
$oreng file , A signal in calibre host runfile
lsf_linux, tapeout_tflex , our scripts to submit mentor graphic calibre jobs and tflex jobs.
with this kind of concept, we can make sure EDA applications which use master and slave compute concept have enough cpu/licenses to run jobs.
Original doc on http://www.teraproc.com/teraproc-blog/eda-cost-savers/