The current HTTP Server for AS/400 is based on a different set of code than the HTTP servers that IBM offers for other environments in its eserver product line—such as pSeries (RS/6000) or xSeries (NetFinity). For those HTTP server implementations, IBM licensed the Apache server from The Apache Software Foundation (www.apache.org). The current HTTP Server for AS/400 product (5769-DG1) is its own proprietary animal and is not based on the open-source Apache server.
In December 2000, IBM was scheduled to release its long-awaited port of the Apache HTTP Server to OS/400 V4R5 via OS/400 PTFs. But the December 2000 OS/400 Apache implementation was targeted as a late alpha/early beta implementation of the product, and it will be followed later this year with more complete and stabilized Apache server releases. In addition, it is expected that Apache will probably be shipped with OS/400 V5R1 when the new operating system debuts later this year.
IBM’s Apache port will have an effect on your OS/400 HTTP Web serving because—once the port is complete—Apache will become IBM’s designated strategic Web serving environment for OS/400. The HTTP Server for AS/400 will still come shipped with OS/400, but it’s important for you to understand how these two products relate to each other and what the future holds for OS/400’s native Web serving environment. To clarify how the OS/400 Apache HTTP Server relates to the current HTTP Server for AS/400 and to provide for some insight for your own OS/400 Web server strategy, here is a rundown on the current situation with these native OS/400 Web servers and how things will change in the future.
Once a final stabilized version is released, Apache will become OS/400’s strategic Web serving product and all new enhancements will be applied only to the Apache server. All new development energies will be focused on Apache. Other IBM Web-based products will be built around the Apache standard, not the HTTP Server for AS/400 standard. The best guess I have for a standard final release version of Apache for OS/400 is with the next OS/400 release—OS/400 V5R1—which may be announced as early as May 2001. However, this is only a speculative date and the actual final product release date is dependent on a number of factors within IBM. Apache Installation and Execution According to IBM, Apache will eventually be distributed with the IBM HTTP Server for AS/400 (5769-DG1) Licensed Program Product (LPP), the same product that the current HTTP Server for AS/400 is distributed in. In its initial releases in OS/400 V4R5, it is being
distributed as a new group PTF for 5769-DG1, and there are no prerequisites for installing the product. Apache will only run in OS/400 V4R5 or above, and it will not be ported to earlier releases.
When OS/400 V5R1 is released, IBM plans to start distributing the server with 5769-DG1, and the Apache server and the current HTTP Server for AS/400 will both be installed when you install this LPP. In addition, you should be able to simultaneously run OS/400 Apache Web server instances alongside your existing HTTP Server for AS/400 server instances so that you can test Apache without disrupting your current OS/400-based Web-serving environment.
For IBM-specific information about installing Apache on the AS/400, consult the HTTP Server (powered by Apache) Web site at www.iseries.ibm.com/products/http/services/Apache.htm. A pointer to all Apache follow- on PTFs should be available at that site by the time you read this story. Is OS/400 Apache Open-source? IBM tells us that the OS/400 Apache HTTP Server is not an open-source product inside OS/400. Rather, it is being delivered as a compiled program, and you will not be able to modify or recompile the source code in any way. IBM is delivering Apache this way because it is enhancing the Apache source to provide the same sort of tight integration between Apache and OS/400 that currently exists between the HTTP Server for AS/400 and OS/400. All of the same hooks that exist for integrating OS/400 objects and data within the HTTP Server will also be available within Apache. Figure 1 lists many of the OS/400 integration features that IBM is porting into Apache.
HTTP Server for AS/400—The Present and Near-future
The HTTP Server for AS/400 will still be shipped with OS/400 for the foreseeable future. However, after the OS/400 Apache Web server port stabilizes, IBM will no longer be upgrading the HTTP Server for AS/400 with new capabilities and abilities. It will become a frozen environment and IBM will encourage customers to deploy applications on the Apache server rather than the HTTP Server for AS/400. The Commercial Software Effect IBM may also be developing its own WebSphere-based Web middleware products specifically for the Apache environment at final release, and these products will probably become more and more Apache-oriented as time goes on. Once that happens, it is unclear how this will affect any existing HTTP Server for AS/400 server instances you may be running. Theoretically, if IBM starts updating and writing WebSphere products to a Java specification, they should be able to interface with HTTP Server for AS/400 instances. However, if IBM enhances the OS/400 Apache HTTP server and its new products take advantage of enhancements that are not available on the HTTP Server for AS/400, well then you’ve got a problem here. If there is new functionality that you need for your e- business applications that is not available on your HTTP Server for AS/400-based Web servers, you may have to migrate to Apache or another alternative at that time.
A similar situation may occur if you’re buying third-party products for your Web serving environment. If third-party vendors write their products with Apache-specific hooks, you could be in the same situation I described in the last paragraph; you need new functionality in your OS/400 Web solution but that functionality is not being provided for your Web serving platform—the HTTP Server for AS/400. This is something to think about as you work on your business plans. The HTTP Server for AS/400 Ticking Clock In some future OS/400 release—and IBM is not specifying any dates yet—IBM plans to discontinue providing the HTTP Server for AS/400 as a feature on its operating system. If IBM releases an upgrade without the HTTP Server for AS/400 and you’re using that product for Web serving, you will have two choices when you decide to upgrade your
machine. You can either forego the upgrade release or you can migrate your Web site to another server such as OS/400 Apache or an alternative running on a different platform.
If your Web site is strategic to your company and you have custom-written Web site applications that use OS/400-specific hooks—such as e-RPG (RPG CGI), OS/400 user profile authentication, or third-party OS/400-based products that ride on top of your HTTP Server—you may need to stay with your OS/400-based Web serving environment and port to OS/400 Apache at that point. If your site is more non-OS/400-specific, you may be able to migrate to another server platform before you do your upgrade. Either way, it involves a port to a different Web serving software environment.
Sources at IBM have told me that the company will eventually discontinue the HTTP Server for AS/400 but they haven’t said when. A key point here is when IBM will do this. To help with my analysis, I’ll do a little extrapolation and see how it affects your decision-making process. IBM generally supports an OS/400 release for around two years. Given that as a starting point, you can assume that the HTTP Server for AS/400 will be available in OS/400 V5R1, which will probably be released in mid-2001 and lose support some time in early 2003. IBM has to carry the HTTP Server for AS/400 in V5R1 because there hasn’t been any advance notice of its cancellation yet and it’s still not a given fact that the Apache OS/400 HTTP server will be in its final stabilized format by the OS/400 V5R1 launch. IBM will probably not issue a second OS/400 release in 2001, so the first release that doesn’t contain the HTTP Server for AS/400 may be a major release to be issued sometime in 2002.
So, if you upgrade to OS/400 V5R1 in 2001, IBM will probably still be supporting the HTTP Server in OS/400 V5R1 and you can retain that support until sometime in 2003. Now, this doesn’t mean that the HTTP Server for AS/400 stops working in 2003. It simply means that—if the HTTP Server for AS/400 is not included in a major release in 2002—the earliest date that IBM may officially stop supporting the HTTP Server in OS/400 V5R1 (i.e., technical support, PTFs) is sometime in 2003.
Of course, if you’re running OS/400 V4R3 or V4R4, your support options are about to run out this year—OS/400 V4R3 loses official support on January 31, 2001; OS/400 V4R4 loses official support on May 31, 2001. See IBM’s OS/400 Release Support Date Web site at www.as400service.ibm.com/supporthome.nsf/Document/17623433 for details—but this 2003 date seems to be a significant date in this scenario. I also set the date at 2003 because—even if the successor release to OS/400 V5R1 is released in 2002 without the HTTP Server for AS/400—you should still be able to purchase an in-between upgrade to OS/400 V5R1 in 2002 because the product is still supported. So, if you wanted to purchase an upgrade in 2002, you wouldn’t be forced into the OS/400 V5R1 successor if you wanted to retain your HTTP Server configurations in V5R1.
Now that I’ve established early-to-mid 2003 as a safe date for continued operation and support of the HTTP Server for AS/400, you should be able to keep using it in a supported mode for the next two years. However, you should also plan for the future and start looking at Apache sometime this year after IBM reaches its final stabilized version so you don’t get caught off-guard in an upgrade withdrawal.
Of course, this date could get pushed out to 2004 if IBM includes the HTTP Server for AS/400 in the 2002 release, and it could even go as far as 2005 if IBM includes it in the major release for 2003. But I’m being conservative here and I’m betting that V5R1 will probably be the last release to include the HTTP Server for AS/400 and making my recommendations accordingly.
The point to be aware of is that you still have time to use the HTTP Server for AS/400, and you can continue developing in it for at least the next two years until you decide you need to upgrade to the first OS/400 version when IBM discontinues the product. At that point, you’ll be faced with the migration problems I’ve outlined. Of course, IBM may also help you out by providing migration tools for porting HTTP Server configurations to Apache. IBM has made no commitment to providing these tools, but Big
Blue still may announce a program in the future, and it would definitely be in the company’s interest to do so.
HTTP Server for AS/400 and Apache Recommendations
In January 2001, the Apache HTTP Server for OS/400 is in a state where system administrators need to take a wait-and-see attitude toward its deployment. Because it is still in a late alpha/early beta stage, using it to deploy production applications is pretty much out of the question unless you’re very brave, very good, or very foolish. I know that Apache is IBM’s future strategic Web server, but I don’t know yet when it will be a stable enough product to actually deploy live applications. However, I also know that the clock is ticking on current HTTP Server for AS/400 support and Apache is probably your best alternative so—if you’re running an OS/400-based Web site or considering launching one—here are my recommendations for how to approach Apache:
• Start or keep developing your OS/400-based Web sites using the HTTP Server for AS/400. If you running OS/400 V4R5, you can download IBM’s early version of the OS/400-based Apache HTTP server and start playing with it in order to get familiar with the product. However, be advised that—in January 2001—this is late alpha/early beta code. It’s unclear how stable the product is, whether the product will be significantly changed by the final version, or whether the product could conceivably have an adverse effect on your OS/400 V4R5 machine. Be careful in using it.
• Keep following the news from IBM about what’s happening with the Apache HTTP Server for OS/400. In particular, watch the HTTP Server (powered by Apache) Web site at www.iseries.ibm.com/products/http/services/Apache.htm. Also, look for any news about HTTP Server-to-Apache migration tools as they would help solve your migration problems. By doing this, you’ll be able to gauge how far along IBM is with its implementation efforts, when you may be forced to move, and the tools you’ll use to move with. Midrange Network Expert follows this type of information on a weekly basis and publishes what is found every Thursday in the Midrange Network Expert Alert (MNE Alert) email newsletter (for subscription information, go to www.midrangecomputing.com/mne/subscribe).
• If you’re not on OS/400 V4R5, you can start getting familiar with the Apache Web server by downloading and installing a version of the product on another server platform such as Windows or Linux. While this won’t be the same as running it inside OS/400 (you’ll be missing all the valuable OS/400-based hooks, such as e-RPG and AS/400 user profile validation, to name a few), it will provide experience on the product that you can use if you decide to run Apache inside OS/400 at a later date. Also, consider upgrading to V4R5 or V5R1 (when it’s available) so you can start working with the product if your business plan
calls for an eventual migration.
• As late 2001/early 2002 wears on, start loading the Apache HTTP Server onto your OS/400-based machine (if you’re on OS/400 V4R5 or above) and start working with the software—if you decide to stay on OS/400 for your Web serving platform. The software should be stabilized by this time and IBM should be in the groove of providing regular PTFs. If you don’t want to migrate to the OS/400 Apache HTTP Server, start evaluating alternatives and begin identifying a Web server platform to migrate to.
• In 2002, plan how you will migrate off the HTTP Server for AS/400 Web server should you need to do so during an upgrade. You should have a clear indication of where you are going and how to get there because your support options may be running out very soon by this time.
• If IBM extends the HTTP Server for AS/400 into the OS/400 V5R1 successor release that will probably be released in 2002, extend all dates by one year. Most of the timetables I provide here are pure speculation based on a conservative HTTP Server for AS/400 service discontinuation date. Because of customer needs, IBM may keep the product much longer than I’ve outlined but the end result will be the same. Apache will become IBM’s only strategic native Web-serving platform.
Don’t Fear Apache
Apache is coming to the AS/400 and it will affect your HTTP Server for AS/400 implementations. The good news is that you have plenty of warning and still have a lot of time to think about what to do. Evaluate all your options and make sure you come up with a concrete plan for your future OS/400-based Web site before you’re forced to.
References and Related Material
IBM’s HTTP Server for AS/400 Web site: www.iseries.ibm.com/products/http
IBM’s HTTP Server (powered by Apache) Web site: www.iseries.ibm.com/products/http/services/Apache.htm
IBM’s OS/400 Software, OS/400 Release Support Web site: www.as400service.ibm.com/supporthome.nsf/Document/17623433
Midrange Network Expert Alert (MNE Alert) email newsletter subscription page, Midrange Computing: www.midrangecomputing.com/mne/subscribe
OS/400 Apache Server Enhancement Possible Implementation and Functionality
Full-function, task-oriented, Web-based user interface IBM is modifying the Web-based Configuration and Administration Utility to allow you to modify either Apache-based or HTTP Server for AS/400- based configurations.
Authentication using LDAP, AS/400 user profiles This may be similar to the protection directives and access control list and validation lists. authentication that currently exists in HTTP server configurations.
Full native SSL support IBM is stating that this will include client authentication and association between client certificates and validation lists or AS/400 user profiles
Logging rollover and archiving of log files IBM is also stating that the Apache server will be able to store log file information in the DDS file format, the same as you can store
HTTP Server for AS/400 log files in DDS.
CGI support for RPG, COBOL, REXX, CL, and Java All of your existing OS/400-based CGI programs, including e-RPG programs, should still be able to run under an Apache Server configuration.
Persistent CGI support and support for CGI scripts Persistent CGI is used to enable your OS/400 CGI scripts to behave running in named activation groups more like normal terminal-based OS/400 programs that can be called iteratively without closing file pointers and retaining variable status when HTML output is delivered to the browser client.
Configuration, Instance, and Groupfile APIs IBM already provides these APIs for the HTTP Server in the QZHBCONF service program in the QHTTPSVR library. It’s unclear whether these same APIs will be used for Apache or whether IBM will provide a new set of APIs.
Global server and instance parameters, the Webserver This is necessary for running any Web server on the AS/400. This also Search engine support, and support for all AS/400 indicates that IBM may be retaining its current HTTP Web server file systems structure of starting an OS/400-based Web site through a server instance that may be attached to a separate configuration file that is stored inside DB2/400. It’s unclear at this point whether you will be able to create one Apache server configuration that can be attached to several Apache server instances the way you can configure your server instances under the HTTP Server setup.
CGI codepage conversion modes These are a necessity for running OS/400 CGI scripts because incoming
CGI ASCII form data must first be translated in EBCDIC before it can be processed in many OS/400 script programs.
Figure 1: Here are some of the features and functionality IBM is planning to program into the OS/400-based Apache Web server.