Posts for the ‘WebSphere’ Category

WebSphere 7 Supports Properties-Based Configuration

Wednesday, August 20th, 2008

IBM WebSphere 7 (currently in beta) comes a property-file based configuration tool that provides a "human-consumable" interface to the currently XML-based configuration repository of the application server. This is another proof that XML is simply not the right mechanism for managing configuration of complex software products.

From the release notes:


Properties (name/value pairs) files are more consumable for human administrators than a mix of XML and other formats spread across multiple configuration directories.

Kudos to IBM for recognizing that.

It is still not clear though how hierarchical relationships between configuration objects will be supported.

Back in WAS 6 world, I've been using a simple jython script that converts python named parameters into wsadmin format. This is an example of a resource described in this format:


 WASConfig.DataSource(parent="testJDBCProvider", name="testDS", jndiName="jdbc/testDS",
                              description="Test DataSource", propertySet=dict(
                              resourceProperties=[
                                  dict(name="dbName", value="testDB", type="java.lang.String" ),
                                  dict(name="connectionAttribute",value="", type="java.lang.String")
                               ]))


I think that a slightly more streamlined python-based format will be superior to properties.

Jython in WebSphere Portal

Sunday, August 10th, 2008

Most developers and administrators working with WebSphere Application Server (WAS) know that both JACL and Jython languages can be used for various WAS administration and configuration tasks. However, JACL has always been a preferred choice, simply because this is the default language used by the product's admin tool (wsadmin) and also because JACL examples and documentation are more complete.

Using JACL might have been a valid option just a few years back (when WAS just came out) given the uncertainty surrounding the Jython project. Today, however, jython is clearly alive and well; an alpha version supporting Python 2.5 was announced recently. Therefore there is really no point in using JACL any longer, except may be for shops with a large collection of existing JACL scripts. JACL syntax is quite arcane compared with Python and the language is clearly not as widely used.

IBM confirmed this view by releasing JACL to Jython converter a couple years back.

Unfortunately, up until recently, jython was not officially supported in another IBM product, WebSphere Portal, which comes with wpsript tool for managing pages, deployable modules and other portal artifacts.

But since portal scripting relies on wsadmin's shell, jython is in fact fully supported by the product, it's just not documented. All that you need to do to switch to jython is to invoke wsadmin with "-lang jython" and "-wsadmin_classpath " followed by the list of portal jars (you can copy the classpath from SCRPATH variable definition in wpscript.sh).

As an example, I put together a simple Jython script for cleaning up a page hierarchy. Removing pages before applying an XMLAccess script with page definitions allows to start portal configuration from a clean "known" state. Very often, especially in a development environment, an application's page hierarchy gets polluted with various "test" pages created by developers. The script gets rid of them.

In WebSphere Portal 6.1 Jython is finally made a first-class citizen. The product's documentation proclaims that JACL support will be phased out and that jython is the way to go. Surprisingly, though, all examples still use good old JACL. I assume it's just a matter of time before they convert.