Archive for the ‘Technology’ Category

Messaging identities

Friday, October 5th, 2007

Given Alasdair has been kind enough to include me in the acknowledgements, that guarantees him a plug for his developerWork’s comment line entitled “Connect an application to the default messaging provider using the run-as identity“. This describes how to connect to the default messaging provider in WebSphere Application Server using the application’s current runtime run-as identity rather than, as is usually the case, the credentials administratively associated with the connection factory or resource reference. As always, just because something is possible, doesn’t mean you should do it, so please head Alasdair’s comments about what to consider before implementation.

WebSphere MQ 5.3 and WebSphere Application Server 6.1

Monday, September 3rd, 2007

A question from a colleague had me wondering about the following restriction stated in the WebSphere Application Server Version 6.1 pre-reqs:

IBM WebSphere MQ 5.3 CSD 12 and IBM WebSphere MQ 5.3.1 for z/OS + PK10303 are supported for client mode connections only.

Fortunately, Paul Titheridge from the service team was able to provide me with an explanation. The use of the WebSphere MQ 5.3 JMS client is not supported in a Java 5 JVM which is, of course, what Version 6.1 of the application server is running on. For a client connection, you should use the WebSphere MQ Version 6 JAR files which are supported under Java 5, and also provide backwards compatibility when making a client connection to a Version 5.3 queue manager.

That said, with WebSphere MQ Version 5.3 due to go out of service at the end of next month then this is probably a largely academic discussion.

Updated: Paul’s explanation of the reasoning behind this statement is entirely correct but, it transpires, that statement is now out-of-date and only tells part of the story. WebSphere MQ 5.3 is now supported with WebSphere Application Server 6.1 providing you have at least CSD 13 of the former and 6.1.0.5 (6.1.0.6 on z/OS) of the latter. You also need to set the MQ_INSTALL_VERSION WebSphere variable as explained in the InfoCenter and this tech note. Thanks to Alasdair Nottingham for picking me up on this.

WebSphere MQ and the client container

Friday, August 17th, 2007

WebSphere Application Server has shipped with JAR files for the WebSphere MQ JMS provider since Version 5.0 as they were, at the time, required for the embedded messaging provider. However, if those JAR files do not match the version of WebSphere MQ you are using (as is the case with WebSphere Application Server V6.0 and WebSphere MQ V6) you may see error messages such as java.lang.NoSuchFieldError: msgToken. As documented on the support site and in the InfoCenter, on the server-side the correct thing to do is update the MQ_INSTALL_ROOT WebSphere variable to point to your real WebSphere MQ installation. What I haven’t seen documented anywhere is what to do in the case where you are using the WebSphere Application Server client container. In that scenario, you need to modify the JMS_PATH environment variable defined in the launchClient batch file in the application server bin directory.

Aggregation with WebSphere ESB

Friday, August 17th, 2007

Aggregation isn’t currently one of the capabilities available out of the box with WebSphere ESB but it’s something a number of people have asked me about in the past, particularly those from a WebSphere Message Broker background. I was therefore particularly pleased when Russ Butek showed me a draft of a developerWorks article he was putting together which demonstrated how to achieve aggregation using a custom mediation primitive. Looks like that article has now been published so you can now read all about it for yourselves.

JMS connection pooling

Thursday, August 16th, 2007

I’ve mentioned one of my colleague Paul Titheridge’s articles before (on JMS Application Server Facilities) and he’s just started a new related series which is well worth taking a look at. This time Paul has turned his attention to the myriad of connection pool properties provided by WebSphere Application Server and what they mean when using WebSphere MQ as the JMS provider. As before, Paul has provided some thoroughly worked examples to help explain the implications of changing different values.

Rails Overview: View

Friday, July 20th, 2007

Having covered the Model and Controller aspects of Rails in previous posts, that really means it has to be View next. I’ve already touched on the basics: the controller method renders a template, either explicitly or simply by exiting and allowing the default template for the action to rendered, and the attributes of the controller class setup by the action method are then available to the template.
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Connecting Enterprise Applications to WebSphere Enterprise Service Bus

Friday, July 20th, 2007

Andrew is plugging the draft of his Redbook Connecting Enterprise Applications to WebSphere Enterprise Service Bus over on SOA Tips ‘n’ Tricks and rightly so as it’s well worth a look. If you thought that WebSphere ESB was just about SOAP/HTTP then this book should set you straight. It covers details of integration via WebSphere MQ, JDBC and HTTP and connecting to CICS. I’ve been working on the labs for the corresponding ITSO Workshop rolling out later this year.

Gallery rewrites are back

Monday, July 16th, 2007

Many thanks to Ilya Azarov who answered my plea for assistance and supplied his nginx rewrite rules for Gallery2. I won’t claim to understand why his work and mine didn’t (although previously I wasn’t aware that you could nest location directives so that was something I hadn’t tried). They still can’t cope with spaces in file names but I can live with that.