IBM® Rational® Publishing Engine web
service provides a remote engine, instead of the local engine used
by default in the Rational Publishing Engine installation.
The Launcher and Document Studio connects to a remote engine and transfers
the publishing process to a more powerful computer or server. Rational Publishing Engine Web
Service is optional and you might choose to install it based on your
business requirements.
Rational Publishing Engine web
service provides server-side facility to relocate potentially resource
and time-consuming publishing operations to a high-performance computer
or server.
Rational Publishing Engine web
service is available as part of the installation. You can also manually
install
Rational Publishing Engine web
service.
Rational Publishing Engine web
service generates documents on the server, offsetting workload on
the client computer. As a requirement to deploy
Rational Publishing Engine web
service, the following application servers are required:
- Apache Tomcat 6.0.18 and later
- IBM WebSphere® Application Server 6.1
- Any Axis compatible application server
Rational Publishing Engine performs
the following actions:
- Provides request queueing to alleviate the resource strain on
the server. Based on the server settings, the server can process a
certain number of publishing requests simultaneously. Further requests
are moved to a queue until a slot is made free by a process that ended.
- Uploads the required artifacts. The launcher prepares an archive
containing required artifacts:
- 1 document specification
- 1 or more templates
- 1 or more style sheet files
These files are unpacked on the server and consumed as required.
- All of the output files are packed into a single archive. Unlike
when using a local engine, a remote publishing process always returns
a single output archive. This avoids the need to download multiple
files.
- Does not upload data. This means the data used for configuring
the document specification must be available in the server context.
- Downloads results.
- Provides the load balancing feature that reduces the workload
directed to a single web server instance by providing a larger set
of web service instances to publish documents. The load balancer redirects
the request to one or more web service instances. If there are a large
number of requests to a particular web service and if that web service
cannot cope with these requests, you can adopt the load balancing
feature.
In previous versions of Rational Publishing Engine,
the only way to publish documents using Rational Publishing Engine web
service was through the Preferences option.
Now, you can use a load balancing gateway entry, which is a URL, to
publish documents using the load balancer or using the existing web
service instance. The server which provides the load balancing returns
a URL that has the address of the web service either in the first
or second instance of the Rational Publishing Engine web
service. When Rational Publishing Engine client
sends the request to this URL, the requests goes through the load
balancer. The load balancer dispatches the request to one of the
available server. You can configure the Rational Publishing Engine launcher
to use the load balancer directly.
This new URL, http://localhost/rpe/wsgate,
which provides a gate to the Rational Publishing Engine web
service, can also be used outside the load balancer environment.
It redirects the Rational Publishing Engine to
the web service URL from the same server. The standard web service
can run in IBM WebSphere Application Server as
well as Apache Tomcat.
Note: The configuration in the load balancer
must use URLs that are visible and can be resolved from all the client
machines that use Rational Publishing Engine.
The local node must be visible and accessible from the Rational Publishing Engine client.
- Provides mobility via connection recovery. For a long remote publishing
process, you can disconnect your notebook from the Rational Publishing Engine web
service processes and reconnect later without losing the connectivity
to that process, and then download the results. On restoring the connection,
you can still retrieve the generated documents. In earlier versions
of Rational Publishing Engine,
if the connection disconnected, the document generation process could
not complete and there was no way to obtain the document although
the document was successfully generated on the server.
- With the web service approach, various clients can be constructed,
for example, Java client, implemented
in Rational Publishing Engine Launcher.
Note: The Rational Publishing Engine Web
Service does not support thin clients. The client must be AXIS2 compatible.