Convergence
One of the main ideas in CFEngine is that changes in computer configuration should be carried out in a convergent manner. This means that each change operation made by the agent should have the character of a fixed point. Rather than describing the steps needed to make a change, CFEngine language describes the final state in which one wants to end up. The agent then ensures that the necessary steps are taken to end up in this "policy compliant state". Thus, CFEngine can be run again and again, whatever the initial state of a system, and it will end up with a predictable result. CFEngine supports the item of statistical compliance with policy, meaning that a system can never guarantee to be exactly in an ideal or desired state, rather one approaches (converges) towards the desired state by best-effort, at a rate that is determined by the ratio of the frequency of environmental change to the rate of CFEngine execution.
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