Architecture overview

Global overview

Holodeck B2B is a standalone application that provides the AS4 messaging capability to your solution. The Holodeck B2B gateway takes care of all complexity related to the message exchange with your trading partner, the business application only needs to provide the business documents and some meta-data telling Holodeck B2B who to send the data to.
The open source version provides a simple file based integration method with the business application.
Using Holodeck B2B’s extension mechanism additional customised connectors can be plugged into the gateway. These can be tailored to the specific requirements of your environment and for example handle validation and transformation of the business data.

Modular architecture

The Holodeck B2B message service handler uses a modular architecture as shown in the picture. It implements the separation of concerns principle to enable easy adaption to the needs of the target environment. The main module is the Core which handles the AS4 message processing.
Around the Core module is an interface layer (the API) operating in two directions:

  • Defining functionality offered by the Core that can be used by connectors and extensions.
  • Defining the functionality needed by the Core which can be provided by extensions.

Using this interface layer, Connectors realise the integration with the business application and Extensions implement the functions needed by the Core, for example the storage of message meta-data.
The open source distribution includes default implementations for the functionality needed by the Core and a file based Connector to integrate the gateway with the business application.

Holodeck B2B layers

Main components

The Archimate model below shows an overview of the main application components that exist in every Holodeck B2B gateway implementation. These components are:

  • Message handlers: these perform the actual ebMS3/AS4 message exchange with the partner gateway. Responsible for the processing of the ebMS and WS-Security headers in the SOAP messages. Part of the Core module.
  • Message database: stores the meta-data of the messages processed by the gateway. Besides the ebMS meta-data this also includes Holodeck B2B specific meta-data like the processing state of the message.
  • Message submitter: the Core component that accepts the business documents and meta-data for sending them using AS4 to the business partner. It checks whether the data can be sent before triggering the sending process.
  • Message deliverers: the components part of Connectors and responsible for the delivery of business documents in received User Messages and notification on Signal Messages to the business application.
  • Workers: these components act as services and handle recurring tasks like triggering pull requests and watching for configuration changes.

Holodeck B2B components