Consider how your environment will be configured to support
the Web services enablement of the service integration bus. Determine
which of the bus-enabled Web services roles you want each server or cluster to perform.
The following figure shows a client request being received by an
endpoint listener, then passed through an inbound port to an inbound
service. It also shows an outbound service passing a request through
an outbound port to an external service.
This following figure shows a client request being received by
an endpoint listener, then passed through an inbound port to an inbound
service. It also shows an outbound service passing a request through
an outbound port to an external service, as well as a gateway service
resembling an inbound service and mapping to a target service.
The figure shows the main component types and flows for bus-enabled
Web services. Of all these component types, only three interact directly
with the world outside the bus:
- The endpoint listeners.
- The outbound ports (which act as service invokers).
- The service destinations (which provide mediation points).
By configuring these component types for a given
standalone server
or cluster, you enable that server
or cluster to perform one or more
of the following associated bus-enabled Web services roles:
- Endpoint. Incoming requests to use an internally-hosted
service (an inbound service) are received at an endpoint, then passed
to an inbound port and sent on to the service destination. Responses
follow the same path in reverse.
- Service invoker. When you create an outbound service (a
mapping to an externally-hosted target service) you configure an outbound
port for each port defined in the target service WSDL. The service
is invoked by passing messages between the outbound service and the
target service through the most convenient available port.
- Mediation point A mediation is deployed to a server or cluster, then configured for a
specific service destination. The mediation acts on messages that
pass through the mediation point (service destination). The action
taken by a mediation depends upon the specific instructions you give
in the mediation handler. For example, you can use a mediation to
change the contents of a message, or to choose a particular forward
route for a message.
You might choose to use a cluster rather
than a standalone application server to support a role for any of
the following reasons:
- Reliability.
- Scalability.
- Performance.
For example, in a production environment you would typically
use a cluster to act as an endpoint.
Note: There is actually a fourth
role of Configuration connection point This role
is never provided by a cluster; only a deployment manager or an unfederated
standalone server can act as a configuration connection point.