Hi here:
What does this mean..
host.processors=4, global_host.nuke=1 ..?
The short version:
Each subjob process will reserve four job slots and one global_host resource called "nuke". A host.processor reservation reserves the given number of job slots on a machine per subjob. This global_host reservation reserves the given number of "nuke" resources per machine per subjob - meaning that multiple subjobs on the same machine only reserve a single global_host resource.
The long version:
To add to dmeyer's correct response above, this reservation can be broken down into two parts:
host.processors=4 - This will reserve 4 job slots for every instance of this job that's running on the farm. By default, a worker has a job slot count that is equal to the number of processing units seen by the OS. So on a dual, quad-core with hyperthreading enabled, the OS will see 2*4*2=16 "processors" which will make Qube assign 16 job slots to the worker. In this case, 4 instances of this job could run on this machine at once (therefore rendering 4 frames in parallel through 4 subjob processes). On a farm with 10 of these render nodes, you could potentially have 40 instances of this job running at once time.
global_host.nuke=1 - This assumes a global_host resource called "nuke" has been created on the supervisor (through supervisor_global_resources - see section 8.5 in the Administration manual
http://pipelinefx.com/docs/). Assuming that is true, this reservation will tell Qube that every instance of this job will use 1 of the "nuke" global_host resources. Nuke's licensing model is one that allows nuke to run multiple instances on a single machine while only consuming a single license. A global_host resource is only counted once per node, regardless of the number of instances running on that node, so even if you were to run 4 instances of nuke on a machine, Qube will only reserve a single "nuke" global_host resource.
To put it together, let's assume you have a 10 node farm, with each node having dual-quad core processors with hyperthreading enabled (therefore each node has 16 job slots), and you've set the supervisor to have global_host.nuke=2 in the global resources.
If you then submit a job with the reservation of:
host.processors=4, global_host.nuke=1
You are telling Qube that every instance of this job will reserve 4 job slots and 1 "nuke" global_host resource. Being that you only have 2 "nuke" global resources, only 2 machines can run this job (or any other job with the same reservation) at any one time. Being that you reserve 4 job slots for every instance, each machine can run 4 instances of this job (4*4 = 16). In this case, then, the maximum number of instances that can run on this farm of 10 machines is 8 - 4 on one machine and 4 on another.