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The iSeries: The Once and Future King

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  • #16
    The iSeries: The Once and Future King

    1. Security. You can offload the web access to a cheap PC in the DMZ, thus preventing DoS attacks on your priary machine. To do this with RPG-CGI would require a second iSeries. Response. Not accurate. You can set up a firewall to allow access to standard port 80, and test inside the firewall on the same iSeries with a different port and web server instance. FACT- we do this ALL the time. 2. Scalability. Java supports multi-threading. RPG does not. As your workload grows, synchronization costs in RPG can get quite high. Also, JSPs are compiled classes and RPG-CGI requires constant re-interpretation of templates. This cost gets dramatic as your number of users increases. RESPONSE - Multi-threading comes at a high cost- the Java web server has to handle it, which is why most people have to buy a huge iSeries/i5 just to serve pages to a very few clients. RPG-CGI is just as compiled as JSP's - depending on implementation. In our implementation, HTML is embedded in the compiled object- there is no more 'interpretation' than a JSP would require to extract HTML from coding logic. 3. Flexibility. Changing a logo on a JSP is as quick as editing a text file. You may be able to do that in RPG, but it requires updating a template file with whatever non-standard template language is being used. And if the templates are pre-parsed for performance, you need to somehow let the server know a template has changed. RESPONSE - Not accurate. Changing a logo in CGI is just the same - you do NOT necessarily have to update a 'non-standard' (whatever that means) template file - you can change a text file on the IFS just the same way. 4. Cost. If cost is truly your issue, you can completely offload the web serving to a cheap (under $1000) Unix box, while keeping your business logic on the iSeries. RESPONSE - Now the issue of scaleability really comes up!!!! Joe- would you seriously want to run your enterprise like this? Are you advocating moving off the iSeries/i5 platform in favor of: compromised security/database integration/scaleability/operating system maintenance and failure possibilities/ hardware failure! This is really a specious argument, and detracts from the whole TCO value proposition of the i5. As in my earler post- a 'UI' is NOT in Java (unless you are talking about Java applets- which is not thin, and which I don't think is your intention). Compiled, native ILE objects delivering web pages through the CGI protocol are just as 'thin' (using your apparent definition) as Java servlets. Duncan Kenzie

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    • #17
      The iSeries: The Once and Future King

      WebSmart by BCD is programmed in a pc based ILE. When a program is generated from the ILE it is an RPG ILE program. It is a CGI program. When I look at the free form RPG that is produced it is very clever and very efficient. Does that answer your question? Or did you have something else in mind. Yes, that answers my question, Chuck. Thanks for the info and anecdotes. As I think I posted here awhile back, I saw a Q&A with BCD on the web doing some related research and they were good answers to tough questions. rd

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      • #18
        The iSeries: The Once and Future King

        Joe Pluta said the following on 3/30/2005 5:10 PM: > What if there was a free, relatively low-feature "JSP Starter Kit" > taht allowed you to quickly knock together a couple of screens that > talked with RPG programs? It could install either as an EAR file with > WebSphere or maybe even with Tomcat. It would allow you to write a > simple program that communicated with a JSP using a data queue, and > instead of EXFMT you did a call to an API to send the data. This might work, but the web-facing UI isn't going to look very pretty. That is, web pages I create tend to look pretty lame. Then you have the issues with getting the web server going; group PTFs that have never been applied and all that good stuff. Anything is better than nothing though! --buck

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        • #19
          The iSeries: The Once and Future King

          Joe said: "I feel badly for you" when the chosen way wasn't his. Then Joe also claimed: "(my) tone was less professional than I would have liked" Pity is a condescending way of showing superiority. While you try to rise above the rubble, you're still deep in it. chuck Opinions expressed are not necessarily those of my employer.

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          • #20
            The iSeries: The Once and Future King

            Ralph, Here are a couple of interesting notes about WebSmart.... 1. It can generate Java or RPG-ILE. I choose RPG. It doesn't really matter to me what gets generated, it always works. 2. In the RPG ILE code that is generated the HTML and JavaScript is included in tables at the end of the program. That makes the program very portable and very, very fast. It doesn't preclude me from using includes from IFS locations if I so desire, though. chuck Opinions expressed are not necessarily those of my employer. "Ralph Daugherty" wrote in message news:6b229b3b.50@WebX.WawyahGHajS... > WebSmart by BCD is programmed in a pc based ILE. When a program is > generated from the ILE it is an RPG ILE program. It is a CGI program. When > I look at the free form RPG that is produced it is very clever and very > efficient. Does that answer your question? Or did you have something else > in mind. > > Yes, that answers my question, Chuck. Thanks for the info and anecdotes. > As I think I posted here awhile back, I saw a Q&A with BCD on the web > doing some related research and they were good answers to tough questions. > > rd

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            • #21
              The iSeries: The Once and Future King

              First, I believe CGI is a solution for any size company. We have done scaleability tests for literally thousands of hits per second on small to medium sized iSeries and i5s and CGI holds up fine. Thank you for the informative points about CGI, Duncan. Could you also bring us up to date on how CGI is implemented now on the AS/400? I have worked with another third party AS/400 web server in the past and they handled web pages within the webserver job space to get millisecond response. My understanding at the time was that the CGI process as used under Unix did not translate well under OS/400, perhaps even a job was launched per web page as I dimly recall. This went further to a generic product like Apache not scaling well to OS/400 because of that process per web page perhaps, but who knows, because IBM wouldn't make Apache available because it competed with their cash cow Websphere. In any event, what is the technical story now on CGI under OS/400 in regards to web page processes and do you have to do something special in an AS/400 specific product to overcome what something like Apache would suffer from? rd

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              • #22
                The iSeries: The Once and Future King

                Duncan, the dicussion is purely RPG-CGI vs. JSP. In that vein, here's a simple way JSP is superior: the web portion can be offloaded to a non-iSeries box. With RPG-CGI it cannot. Fair enough? Joe

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                • #23
                  The iSeries: The Once and Future King

                  I am going to respond to one point. 1. Security. You can offload the web access to a cheap PC in the DMZ, thus preventing DoS attacks on your primary machine. To do this with RPG-CGI would require a second iSeries. Response. Not accurate. You can set up a firewall to allow access to standard port 80, and test inside the firewall on the same iSeries with a different port and web server instance. FACT- we do this ALL the time. DoS attacks occur on port 80. I'm really done arguing here. You disagree, and people can read your posts and balance them against mine. Thanks for your input. Joe

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                  • #24
                    The iSeries: The Once and Future King

                    The whole cheap PC thing is really dumb. There, I'm done too. rd

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                    • #25
                      The iSeries: The Once and Future King

                      Joe said back to Duncan Kenzie: "I'm really done arguing here. You disagree, and people can read your posts and balance them against mine. Thanks for your input." Help me understand. When it was just us schmoes who don't know about the underpinnings of how CGI and JSP works the flames were a flying. Your keyboard must have been on fire! Now that an expert opinion based upon real world testing is presented, not theoretical knowledge, the heat in the kitchen is too hot? And, silly me, I was conceding to your views. chuck Opinions expressed are not necessarily those of my employer.

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                      • #26
                        The iSeries: The Once and Future King

                        This sort of provocation is why I chose to leave the conversation. However, Duncan raises some points which I was unable to address, as I had a sick baby on my hands. Now that he's down hopefully for a bit of a nap, I can respond. After this latest personal attack, however, I shall ignore your posts, Chuck. Joe

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                        • #27
                          The iSeries: The Once and Future King

                          Why is a cheap PC dumb? Offloading web serving tasks to a PC is exactly equivalent to offloading I/O tasks to an IOP. Since all it is doing is presenting the web interface, and not serving any critical data, it's a perfect solution for some situations. Personally, I dno't think its optimal, but I have one client using a FreeBSD box to serve pages using data from an AS/400 and they're quite happy. Joe

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                          • #28
                            The iSeries: The Once and Future King

                            Okay, I have an opportunity to respond, and hopefully I can do it as professionally as you, Duncan. First off, though, I want to be sure what we're takling about here. We're talking about RPG-CGI out of the box vs. JSP Model II to an RPG bakc end. In no way am I implying anything about BCD WebSmart. I submit that there are vendors who have managed to get RPG-CGI to work quite well; Nathan Andelin does some stuff that's just incredible. At the same time, people like Paul Holm have done incredible things with the JSP Model II approach. I was trying to compare technologies, and the conversation kept getting dragged to WebSmart, which is NOT a technology, it is a vendor tool. If you disagree on that point, please stop reading here, because i guarantee we will be unable to reach consensus on anything else. If, however, you are willing to grant that comparing JSP Model II and RPG-CGI is an exercise worth further discussion, then please continue. Security: I hope I've explained that point above. With a dedicated web appliance front end, be it Unix or Windows, you open ZERO potrs from your iSeries to the Internet. This is better from a security purist standpoint because even one open port can be sbujected to a DoS attack, thereby affecting the operation of your production machine. There are ways to limit this, of course, but it's simply one less hole. Does that make sense? If you wanted to get REALLY twisted about it, you could write your own SNA routines and not have any TCP/IP connectivity at all, but that's probably overkill . Scalability: Each RPG-CGI session requires a job. Each Java thread does not. Now, if you create a sufficiently thin RPG-CGI layer, much like the way I talk about a JSP Model II veneer, then you can conceivably avoid many of the issues. However, most CGI deployments I've seen basically have a big old program responding to each HTTP request. This is another reason I avoid the discussion of tools like WebSmart. Since I don't know the tool that well, I don't know how they've engineered their infrastructure. But even if they've done it well, the fact that one vendor has such an infrastructure doesn't mean that RPG-CGI programs in general are scalable. So in the end, all I'm saying is that I think threads are more scalable than jobs, and the folks I've talked to at IBM tend to agree. Flexibility: I wasn't rigorous enough here. There are three ways to create CGI output. You can format and write your stream yourself, you can use a template language such as CGIDEV2 or you can use a vendor tool. Leaving the vendor tool out, that means that you must either build your own infrastructure for doing things like includes, or you have to rely on the tags in the CGIDEV library. Either one is more than what is required with JSP Model II. JSP Model II already has all of those features in place in a standard, well-known format. There are even external tag libraries that can simplify many tasks, although I personally don't like them (but that definitely is a presonal bias). In any event, the point is that there is no standard tag language for RPG-CGI to perform standard UI generation tasks such as server side includes and dynamic data access. Is that clear? Cost: A cheap Unix box is an excellent choice for people with small AS/400s (not iSeries!) who either cannot afford 1GB of AS/400 memory or who are simply running on older machines that don't handle Java well. In these cases, RPG-CGI may run better, I don't know. But I have no problem offloading web serving to a dedicated machine, especially when security is an issue (see above). People always complain about how Java runs better on their PC than on the iSeries; here's a way to take advantage of that! Anyway, I hope I've made my position clear. This is simpyl RPG-CGI vs JSP Model II, and completely divorced from vendor tools, mine or anyone else's. It's quite possible that WebSmart has addressed these and many other issues, but frankly I cannot in good conscience get into that discussion. At the fringes we compete (really we don't; my clients and BCDs have clearly different requirements sets), but more importantly BCD advertises with MCPress and I'd rather not try to find fault with an advertiser. Thanks again for a cogent and reasoned discussion, Duncan! Joe

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                            • #29
                              The iSeries: The Once and Future King

                              Joe said: "Why is a cheap PC dumb? Offloading web serving tasks to a PC is exactly equivalent to offloading I/O tasks to an IOP." Not exactly, I've never had an IOP fail in 30 years of using IBM midrange. Can't say that about a PC. However on the Power 6 this will be a moot point as Frank Soltis claimed at Spring COMMON that IOPs will go away in the Power 6 version of iSeries. chuck Opinions expressed are not necessarily those of my employer.

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                              • #30
                                The iSeries: The Once and Future King

                                Joe, I only respond in kind. It's a little late to jab and then walk out of the room claiming you don't like return jabs. chuck Opinions expressed are not necessarily those of my employer. "Joe Pluta" wrote in message news:6b229b3b.61@WebX.WawyahGHajS... > This sort of provocation is why I chose to leave the conversation. > However, Duncan raises some points which I was unable to address, as I had > a sick baby on my hands. Now that he's down hopefully for a bit of a nap, > I can respond. > > After this latest personal attack, however, I shall ignore your posts, > Chuck. > > Joe

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