GHN Manager

Introduction

The gHNManager is a gCube Local Service deployed together with the gCore package. Its main role is to provide an interface (mainly exploited by the VRE Manager service) for managing the node as well as publishing node information. The service is responsible for a correct management and changes of the scope of the GHN and RI resources representing the node and the locally deployed service instances.

Implementation overview

The gHNManager is a stateless service since it manages the state of local GCUBE Resources (node and instances). The service has one port-type providing the operations to manipulate such a state. As it has to be contacted in all the GHN scopes, it is always in all the scopes of the node resources.

Operations

The main functions supported by gHNManager (thanks to the support of the gCube Application Framework and its scope management) are:

• addScope() – takes as input a valid scope expression; the scope is assigned to the gHN
• removeScope() – takes as input a valid scope expression; the scope is removed from the gHN
• addRItoScope() – takes as input a valid scope expression, a service name and a service class; the scope is assigned to the local instance identified by the given name and class.
• removeRIScope() – takes as input a valid scope expression, a service name and a service class; the scope is removed from the local instance identified by the given name and class.
• shutdown()– takes as input a set of non-mandatory options; as basic behavior it shutdowns the gHN, depending on the input options, the gHN state is cleaned and the container is restarted.