Evolution of the Open Cloud Computing Interface

The OCCI standard has been in use for half a decade, with multiple server-side and client-side implementations in use across the world in heterogeneous cloud environments. The real-world experience uncovered certain peculiarities or even deficiencies which had to be addressed either with workarounds, agreements between implementers, or with updates to the standard. This article sums up implementers’ experience with the standard, evaluating its maturity and discussing in detail some of the issues arising during development and use of OCCI-compliant interfaces. It shows how particular issues were tackled at different levels, and what the motivation was for some of the most recent changes introduced in the OCCI 1.2 specification.