Answers to questions such as what is the web services gateway
and how does it work.
What are web services?
Web services
are modular applications that interact with one another across the
Internet. Web services are based on shared, open and emerging technology
standards and protocols (such as SOAP, UDDI and WSDL) and can communicate,
interact and integrate with other applications, no matter how those
applications are implemented.
What is the web services gateway?
The gateway provides you with a single point of control, access and
validation of Web service requests, and you can use the gateway to
control which services are available to different groups of web service
users. For example you can use the gateway to make available controlled
sets of web services for use within your organization and by external
users. The services that each gateway instance makes available as
web services can be a mixture of internal services that are directly
available at service integration
bus destinations and external web services.
This approach provides the following benefits:
- The gateway service is made available at a different web address
to the target service, so you can replace or relocate the target service
without changing the details for the associated gateway service.
- You can have more than one target service (that is, more than
one implementation of the same logical service) for each gateway service.
- The gateway service can be made available on a different service
integration bus to the target service.
- The gateway provides a common interface to the services in each
set. Your gateway service users need not know where each underlying
service is located, or whether the underlying service is being provided
internally or sourced externally, or whether there are multiple target
services available for a single gateway service.
How does the web services gateway work?
When you create a gateway service
, you map an existing
destination that hosts a target service (either an internal service
or an external web service) to a new web service that seems to be
provided by the gateway.
Who should use the web services gateway?
An enterprise that chooses to share its resources selectively
with its business partners and customers, or an enterprise that uses
external web services and wants to make them available internally.
IT managers and developers, who deploy resources, can also benefit
from this technology.
What business problems are solved by the web
services gateway?
The gateway solves the following business
problems:
-
Securely "externalizing" web services:
Business
applications that are exposed as web services can be used by any web
service-enabled tool, regardless of the implementation details. To
better integrate your business processes, you might want to expose
these assets to business partners, customers and suppliers who are
outside the firewall. The gateway lets clients from outside the firewall
use web services that are hosted within your enterprise. Using the
gateway, you can control access to each of these services.
-
Better return on investment:
Any number of partners
can reuse a process that you develop as a web service.
-
Use of existing infrastructure:
With the gateway,
you can make readily available as web services any combination of
your existing internal services and external web services, no matter
how each of those existing services are currently accessed (for example
through a service integration bus destination, a web address or a
UDDI registry).
-
Protocol transformation:
You might use one particular
messaging protocol to invoke web services, whereas your partners use
some other protocol. Using the web services gateway, you can trap
the request from the client and transform it to another messaging
protocol.
How do I migrate from a previous version of
the gateway?
You use the wsadmin tool to migrate a
WebSphere® Application Server Version 5.1 gateway to the gateway
capability that is provided in Version 7.0 by completing the steps
described in Migrating a Version 5.1 Web services gateway configuration.
Can a gateway that is fully integrated within
IBM service integration technologies co-exist with a previous version
of the gateway?
A
WebSphere Application Server Version 7.0 cell can
contain Version 5.1, Version 6 and Version 7.0 application servers,
so you can continue to use Version 5.1 gateways that are deployed to Version 5.1 application servers even
if you migrate the cell from a Version 5.1 to a Version 7.0 deployment
manager. However, before you migrate the cell you must preserve the
gateway configuration as described in Preserving a Version 5.1 gateway when migrating a cell.