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Extended Enterprise::Exposed Direct Connection application pattern::Runtime patterns
On this page, two categories of Runtime patterns are described:
Generic Exposed Direct Connection runtime patterns
When using the Exposed Direct Connection runtime pattern, shown in the figure below, the source application uses a connector to access the target application.
The connector itself may be explicitly or implicitly modeled. If the connector is explicitly modeled, the modeler can use decomposition and abstraction techniques to expand the connector to the appropriate level of detail.
The term Connector may be qualified by both the connector variation and by the interaction variation. Some examples are:
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Adapter Connector
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Path Connector
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Message Connector
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Call Connector
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Call Adapter Connector
The target application relies on services provided by its hosting server. These are modeled using the Application Server/Services component.
The Rules Directory may or may not exist. If it does exist, it is a modeling decision as to whether it needs to be shown in the Runtime pattern. For example, analysis may determine that connection rules are not an important part of the solution, so the Rules Directory may be left off the Runtime pattern.
The Directory and Security services node supplies authentication and
authorization services. It also holds the user ID and password and related
privileges. This node typically leverages LDAP-based directories. It also contains
configuration information needed to support secure access between the
enterprise and partner services.
Exposed Direct Connection application pattern::Runtime pattern
(Click a node to get a detailed explanation.)
Design Last Updated: 11-11-2005
The figure above shows a standard pattern of Path Connectors (firewalls and network infrastructure), but other variations do exist with fewer or more firewalls.
The secure zone Exposed Connector is primarily concerned with logical connection of the Path Connector to the Application Services, and will therefore often be modeled as an Adapter Connector.
Less secure applications and connectors may be placed within the Demilitarized Zone, depending on local security policies; they are usually placed as shown in the figure above.
The Connector in the Enterprise Demilitarized Zone may or may not be modelled. It provides connectivity from the Enterprise Secure Zone to the Inter-enterprise Zone. It may be a low level component (e.g. TCP/IP infrastructure) which is omitted from the diagram or it may have more advanced capabilities such as caching of reusable content (e.g. a Web server).
This Runtime pattern allows two different organizations to talk to each other with a mutually agreed message format and protocol. Each partner can use their own internal messaging format, using a connector adapter to convert from the internal format to the external format.
You may notice that we don't have separate Runtime patterns for the message and call variations of the Exposed Direct Connection application pattern. It is still important to identify that your business scenario requires a message or call application pattern because you can use this knowledge as a consideration when selecting a Product mapping. In the next section we highlight Product mappings that have a more natural fit to the Application pattern message variation or to the Application pattern call variation.
SOA profile
In this second section we specialize the Exposed Direct Connection pattern for the SOA environment using the SOA profile. The SOA profile terminology is indicated using the [SOA] qualifier.
The generic Exposed Connector, Rules Directory and Partner Infrastructure shown above are specialized in the SOA profile to:
- an Exposed ESB Gateway (supporting the Exposed requirement)
- an ESB (supporting the Connector and Rules Directory requirement plus the SOA infrastructure requirement for service location transparency and interoperability, encapsulated reusable business function and explicit implementation-independent interfaces)
- Service Consumers and Providers representing the Partner infrastructure
[SOA]Exposed Direct Connection runtime pattern (aka Exposed ESB Gateway composite pattern)
(Click a node to get a detailed explanation.)
Design Last Updated: 11-11-2005
Next, review product mappings for this Runtime design.
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