The load metric, provided to all of the load distribution algorithms in chapter 8, is a three dimensional vector of CPU, memory and IO utilisation.
This load vector is further refined by each load distribution algorithm to provide its desired type of ranking. For example, the standard metric used in the simulation is the average of the vector components:
The resource based algorithms use the three vector components individually, as explained in section 8.3.1.
Resource utilisation values are used in the load vector, as unlike the queue length, the range over which they occur is well bounded. This behaviour is important for the resource based algorithms, and to ensure comparability and fairness, all algorithms employ utilisation.