Tony Hoare: Invention of the null-reference a billion dollar mistake

Computing Pioneer Sir Charles Antony Richard Hoare (aka C.A.R. Hoare) was mostly known for his Quicksort algorithm, but less remembered for the idea of the “null-reference”. He noted in 2009 that it was his “billion-dollar mistake” which he regretted and only implemented it because it was so easy to do: I call it my billion-dollar […]

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Service Level Agreements for Carrier-Grade Clouds: beyond best-effort

Service Level Agreements (SLAs) are a the nuts and bolts of a business agreement and next to QoS and Security the final pillar of a Carrier-Grade Cloud offering. SLAs define functional and non-functional conditions under which the service should be delivered. They allow for penalties or compensations to be directly derived. Ironically these SLAs have historically been best-effort, static (sometimes paper) constructs, taking only […]

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