Class of information

There are three broad classes of information gathered for load balancing: The configuration of a system (see #tbcnf#2481>) must be known so it can be compared meaningfully with other systems. The system state is monitored periodically. The processes that run may be characterised so that they can be scheduled - this can be done short term as they run based on very recent history, or long term based over a number of runs - this is especially true of embedded and real time systems.

Table: Typical System Configuration Information

In addition, in a distributed system, it is necessary to have other configuration information - in particular the relative proximity of processes, processors and data. In a large system this may involve interacting with routing/topological information (e.g. bandwidth and delay/latency and error rates of lines between systems - for instance FDDI may be faster than bus access for some systems or in other words remote file access than data migration to a slower disk).