The Cloud Provider Ranker is a standalone REST WEB Service which ranks cloud providers basing on rules implemented with the Drools framework.

The INDIGO PaaS Orchestrator interacts with it in order to obtain a ranking of two or more cloud providers basing on particular rules.

The aim of this micro component is to fully decouple the ranking logic from the Orchestrator's business logic.

The Cloud Provider Ranker can be installed on any machine which is reachable from the Orchestrator via TCP connection (including the machine running the Orchestrator itself). It can be set up to listen on plain or on SSL socket, using HTTP as transport.

It is a fully stateless service; it can be used by several Orchestrators, or by any other REST client complying with the expected JSON request.