DARPA ULTRALOG Final Report - Industrial and Manufacturing ...

Manuscript for IEEE Transactions on Automatic Control 20
8. Empirical results
We ran several experiments using discrete-event simulation to validate the designed control
mechanism. Though we use a small network in the experimentation for validation purpose, the
decentralized model, especially, can handle much larger networks.
8.1 Experimental design
The experimental network is composed of fifteen components with a tree structure as shown
in Fig. 8. Each component in the lowest position has 200 root tasks. Also, all the components
have a common linear value function and the cost of completion time is linear increasing
function as indicated in the figure.
A 1
A 2
CCT(T) = 4T
A 3
A 15
A 4 A 5
A 8 A 9 A 10 A 11
A 6 A 7
A 12 A 13 A 14
200 200 200 200 200 200 200 200
Fig. 8. Experimental network configuration
We set up four different experimental conditions as shown in Table 2. There can be stressors
which share resources with components. We assign weight w i to a component i and w i ′ to a
stressor sharing resource with component i. A stressor, which has infinite work (continuously
requiring resource), can impose different levels of stress on the component directly by changing
w i ′. When it is zero there is no stress, and as it increases the stress level increases. We implement
the stress environment by using a weighted round-robin scheduling, in which CPU time received