Databases Reference
In-Depth Information
Moving service location
To virtualize the address of our service, we use the business service in the Service
Bus. We covered creating a business service in
Chapter 2
,
Writing your First Composite
.
Note that we are not limited to services described by WSDL. In addition to already
defined business and proxy services, we can base our service on XML or messaging
systems. The easiest to use is the WSDL web service.
Endpoint address considerations
When specifying endpoints in the Service Bus, it is generally not
a good idea to use localhost or 127.0.0.1. Because the Service Bus
definitions may be deployed across multiple nodes, there is no
guarantee that business service will be co-located with the Service Bus
on every node the Service Bus is deployed upon. Therefore, it is best
to ensure that all endpoint addresses use virtual hostnames. Machines
that are referenced by a virtual hostname should have that hostname
in the local hosts file pointing to the loopback address (
127.0.0.1
)
to benefit from machine affinity.
When we selected the WSDL we wanted to use in
Chapter 2
,
Writing your First
Composite
, we were taken to another dialog that introspects the WSDL, identifies any
ports or bindings, and asks us for which one we wish to use. Bindings are mappings
of the WSDL service onto a physical transport mechanism such as SOAP over
HTTP. Ports are the mapping of the binding onto a physical endpoint such
as a specific server.
Note that if we choose a port, we do not have to provide physical endpoint details
later in the definition of the business service, although we may choose to do so. If we
choose a binding because it doesn't include a physical endpoint address, we have to
provide the physical endpoint details explicitly.
