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Want to hear more from Jim Mason, David Slater and Bradley Stone on Web development? You've got it. Guest speakers from Search400's Live Expert Webcast Web decisions: Which development tool is right for you?, Mason, Slater and Stone answer questions they were unable to get to during the live event.
We are a software package vendor. If we "WebFace" our software, do our customers have to have anything on their AS/400 (like WebSphere Application Server) to run our WebFaced applications?
Slater: When you create a Web interface with IBM WebFacing tool, the same application supports both a Web and 5250 interface. Normally no changes are required to either the DDS or application source code. The Web interface is composed of standard Java components, JSP, servlets and Java beans that will run in any application server that supports these components (almost every application server). You do need an application server to run the Web interface.
Can you do session management with e-RPG? If so, how?
Stone: Session management can be performed either using a "persistent" connection or cookies.
Using persistence is explained in the Web Programming Guide. Using this method each user will use his own job. This is different from normal Web programming in which the jobs running are shared between the users accessing the site. Depending on your site activity, this can result in a number of jobs running at the same time.
I prefer to use the cookie method. In this case you place a cookie on the client's machine with a unique identifier. Then, each time you run a Web page, you read this cookie from the client's machine, telling you which client you are "talking" with.
How does e-RPG performance compare with that of NetData macros?
Stone: e-RPG has a performance edge over Net.Data. That is mainly because Net.Data macros are interpreted, and e-RPG is compiled. The interpretation process takes more resources and subsequently is a little slower than native RPG CGI applications.
What is your assessment of the Web development tools that are available for the 400 today, including ASNA, LANSA, BCD, MRC and WebSphere?
Slater: With the new release of the workstation tools announced on June 4, 2002, WebSphere Development Studio for iSeries is the most comprehensive and integrated suite of tools on any server. And IBM has shipped over 60,000 copies of the tool set and so the tools are pervasive in the iSeries marketplace.
ASNA is a direct competitor to VisualAge RPG, which is a component of WebSphere Development Studio for iSeries. Both ASNA and VisualAge RPG are primarily used for creating client/server solutions using RPG.
LANSA is the most popular 4 GL for the iSeries marketplace. LANSA has plans to integrate their tooling to the new Eclipse workbench, which is shipped in the latest version of WebSphere Development Studio for iSeries. Sorry, I don't have enough information to comment on BCD and MRC
Mason: MRC is also a 4 GL tool for the iSeries. I don't know about any plans they may have for Eclipse integration. Originally, it was a report writing solution. RPG application was added and now Web application generation. Check http://www.mrc-productivity.com/home.html for more information.
FEEDBACK TO RESPONSES
- ASNA's Visual RPG (AVR) can indeed be used to create client server apps. We have hundreds of shops doing so, connecting Windows apps to their iSeries/400s. However, we also have hundreds of customers around the world using AVR to create Web
applications that connect to the iSeries/400.
For example, take a look at http://www.wasserstrom.com -- all done with AVR and by a single RPG coder. But don't stop there! Check out http://www.asna.com/web_solutions.asp for many other AVR Web success stories. Don't think these success stories are limited to the U.S., either. We have distributors in 19 foreign countries and many of these, especially Spain, are hotbeds of AVR-iSeries/400 Web activity.
-- Roger Pence, ASNA education director
Where can we find the tutorial downloads Jim mentioned?
Mason: Our QuickWebSupport site will have a whole set of tutorials on the Web development wizards in the new WDSC product. The tutorials are free for download. You have to register to download the tutorials, but registration is also free The site is: http://groups.yahoo.com/group/QuickWebSupport/. The first tutorials will be on the site by June 30, 2002.
QuickWebEducation -- QWE WDSC tutorials
The model for EACH tutorial includes the following:
1- Define use cases for the tutorial
2- Related WDSC concepts review
3- Load and run a sample application
4- Steps to build your own sample application
5- Tips for building, delivering whole applications
6- Next steps for learning the tools
The QWE WDSC tutorials last about two hours each and cover the following topics:
1- QWE WDSC introduction -- what, why for Web development
2- QWE WDSC project workbench basics
3- QWE WDSC host development- RPG, COBOL
4-- QWE WDSC Web data access applications
5- QWE WDSC Web program call application
6- QWE WDSC XML data access application
7- QWE WDSC B2B Web services application
Will IBM support WebFacing with Tomcat?
Slater: The IBM WebFacing Tool creates standard Java components that will run in any application server, including Tomcat.
I hear that WebSphere is "free," but I also hear WebSphere has a cost. What do I really need for full business use?"
Slater: WebSphere Development Studio for iSeries is a tier-priced iSeries host product. However, the product is a no-charge upgrade from our iSeries AD tools (like RPG and ADTS) with software subscription. Since approximately 85% of our customers have software subscription, WebSphere Development Studio for iSeries is a no-charge upgrade for most customers.
The IBM WebFacing Tool creates standard Java components that will run in any application server, including Tomcat and WebSphere Application Server, Standard Edition, V3.5. Both of these application servers are no-charge options for iSeries customers.
I need a way to generate and deploy WebFaced apps in batch (many logic changes per day). Are there plans for a batch function?
Slater: IBM WebFacing Tool runs on a workstation and creates the Web interface in a batch process. The Java components are then deployed to the application server in a batch process.
If you are making code changes that impact the display file DDS, then the screens that are impacted by these changes can be reconverted and redeployed. You don't have to reconvert all of the DDS display file source.
Is e-RPG synonymous with RPGILE and/or RPG FREE?
Stone: The term "e-RPG" is simply a term that I created to describe RPG programs that are used for Web application development.
Initially, the WebFacing tool could only display one DDS record format at a time. Is that still true or can it now display multiple formats?
Slater: IBM's WebFacing Tool creates separate JSPs and data beans for every DDS record format. WebFacing Tool can generate a very sophisticated Web page consisting of many JSP and data bean. The WebFacing Tool has been used to convert sophisticated ERP applications consisting of approximately 18,000 screens.
Where can I find evaluations of the many vendors offering programs for using the AS/400 from a browser?
Mason: Although IBM doesn't make it easy enough to find, there is a Web site that lists many of the third-party tools available for iSeries development. Some vendors have newer tools that AREN'T listed yet like ebt-now's QuickWebFactory for rapid Web enablement extending the new IBM WDSC tools, but this is good place to start. Go to http://www-1.ibm.com/servers/enable/tools/index.html.
Where can I get information on installing and using the tools, particularly CODE400? Is there a tutorial?
Slater: IBM has developed education courses covering all of the tools in WebSphere Development Studio for iSeries. We are in the process of updating these education courses for the next release. We will also be running a pilot program on delivering these education courses through the IBM partner channel.
There are also Getting Started tutorials for some of the tools. CODE has a getting started tutorial in the product.
Mason: Our QuickWebSupport site will have a whole set of tutorials on the Web development wizards in the new WDSC product. The tutorials are free for download. You have to register to download the tutorials, but registration is also free The site is: http://groups.yahoo.com/group/QuickWebSupport/. The first tutorials will be on the site by June 30, 2002.
QuickWebEducation -- QWE WDSC tutorials
The model for EACH tutorial includes the following:
1- Define use cases for the tutorial
2- Related WDSC concepts review
3- Load and run a sample application
4- Steps to build your own sample application
5- Tips for building, delivering whole applications
6- Next steps for learning the tools
The QWE WDSC tutorials last about two hours each and cover the following topics:
1- QWE WDSC introduction -- what, why for Web development
2- QWE WDSC project workbench basics
3- QWE WDSC host development- RPG, COBOL
4-- QWE WDSC Web data access applications
5- QWE WDSC Web program call application
6- QWE WDSC XML data access application
7- QWE WDSC B2B Web services application
What about Java performance? We have a French company using Java, and when they reverted back to RPG, response times were improved from 50 seconds to less than 3 without expensive server upgrades.
Slater: This is unusual. There are some examples where a Java version of an application runs faster than the RPG version. Normally, you could expect the Java version to be slightly slower because object-oriented applications tend to have a few more instructions, but I would expect less than a 50% increase in response time.
It sounds like either the Java code is poorly written or the Java application has been copied from another platform that requires frequent garbage collection. Many Java applications written for Windows have frequent garbage collection routines built in. These are not required on the iSeries. Once the applications are adjusted to do less garbage collection they usually run faster on the iSeries and compare reasonably to RPG applications. However, if you are writing business logic for the iSeries server, ILE RPG and ILE COBOL are the most productive languages.
Mason: Yes, a badly written application in ANY language will perform poorly. From a design standpoint, Java servlets run very well compared with RPG CGI for Web applications. For batch iSeries applications, Java CAN run reasonably well, though generally not as fast as RPG. The one scenario that is generally poor for Java is calling Java from an RPG application. It has to create a BCI job to run the Java code as well as start the JVM, load classes, etc. For instance an MRP job written in RPG would NEVER call a Java subprogram in this scenario to perform date calculations on each line item read by the RPG program! IF you need to call Java from RPG for batch scenarios, the best way is to start the Java program running in batch and communicate using a "message" model to send a request and read the result through a request table, data queue or MQ.
Stone: This can be the result of one of many things. First, most older machines are not tuned to run Java efficiently. Second, because Java requires its own virtual machine, the performance will rarely be as good as a native RPG program. Lastly, when developing applications in Java, you must pay special attention to performing actions such as reading from a database. If you are not using techniques such as database connection pooling, you will see a decreased performance because making the connection to the database can take a lot of time.
In time, the hardware will "catch up" with the performance requirements of Java and other languages to come. But this also means that RPG should perform that much better. I always say, if a machine will run Java fast, just imagine how fast RPG will run!
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About the speakers: Jim Mason is president of ebt-now; David Slater is World Wide Market Manager of iSeries Application Development at IBM, and Bradley V. Stone, author of the best-selling book e-RPG: Building AS/400 Web Applications with RPG.
