The hooks package

Here are some of the built-in plugin interfaces; all are in org.jtrix.project.beatrix.plugins.hooks and all are used by the Manager and Worker netlets. Those marked (*) are also provided by the Manager netlet, while those marked (**) are provided by the Worker netlet. So unless otherwise stated, we should not implement our own plugins of these types. Figure  also shows this.

IBeatrixSASSupport

Allows Beatrix to use a service advertisement service (SAS). Only needs to be provided by an implementation of the SAS.

IDeploymentControl (*)

Manages the process of deploying the right netlets on nodes with the right resources. Most applications will not access this directly.

IInternalFacetProvider (*)(**)

Provides internal facets for intra-application communication--see Section . Although the Manager and Worker implement these it is likely we will also want to implement our own application-specific IInternalFacetProvider plugins.

ILeaderSupport (*)

Functionality to help the current leader (Section ).

IManagementState (*)

Helps access the management state available to all managers (Section ).

IManagerLifeCycle

Deals with managers starting (cold starts, warm starts and joins) and leadership changes. Every application needs to implement one of these otherwise the application cannot start. See Section .

IManagerSupport (*)

The core work of managers, including the ability to generate warrants for consumers (Section ).

IPeerSupport (*)(**)

To help managed netlets be part of their application peer group. Find other netlets, announce service eligilibility and set status. See Section .

IServiceManager

Collection point for services. Services register with this and can then be retrieved easily as needed--it is a plugin which is also a plugin manager. Every netlet which wants to provide services needs a service manager and, since this is not necessarily all netlets, Beatrix does not add an IServiceManager by default. See Section .

ITransportProvider

Allows us to change Beatrix's internal network communication mechanism.

IWorkerLifeCycle

Allows a manager to respond to workers stopping and starting (Section ).

IWorkerResourceProvider (**)

Allows a worker plugin to access the resources allocated to that worker. See Section .