Consider how
your environment will be configured to support
service integration bus-enabled web services. Determine which of the
bus-enabled web services roles you want each server or cluster to perform.
Figure 1. A
service integration environment with a gateway service 
These figures show 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
stand-alone 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 stand-alone 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 a fourth role of Configuration
connection point. This role is never provided by a cluster; only
a deployment manager or an unfederated stand-alone server can act
as
a configuration connection point.