An overview of the OASIS TOSCA standard: Topology and Orchestration Specification for Cloud Applications
Cloud computing has seen an immense rise in recent years, both in new technologies being released as in subsequent use by industry. The use of resources spread across the globe in an on-demand scalable manner, tied to pay-as-you-grow payment schemes, has made the Cloud very attractive. However in part due to this rapid growth, limitations are showing in the majority of Cloud-enabling technologies. More specifically, they lack the capability of providing a standardized view on similar resources served by different providers or through different Cloud middleware solutions. This results in an inability to migrate applications across different platforms without investing high cost and time. This is called the vendor lock-in problem and in order to resolve it, each component of an application, their relationships and management configurations must be encoded in a portable, standardized and a machine readable format. To this end, TOSCA -- the Topology and Orchestration Specification for Cloud Applications (Version 1.0) was released. This standard offers a structured (XML based) language that defines different components of an application and relations between them using an application topology while capturing all management tasks in management plans. The main motivation behind this document is to provide an informational overview of TOSCA to people who are new to the recent developments in the field. As such, this document contains a description of a representative set of works in literature that made contributions to TOSCA.