IBM’s licensing agreement with the Apache Software Foundation prohibits IBM from referring to its OS/400 implementation of the Apache Web server as Apache, because IBM is not distributing the Apache source code with the OS/400-based server; hence the name HTTP Server (powered by Apache). However, we here at Midrange Computing really dislike typing long product names (we’re lazy), so—just as we call AS/400 Client Access Express for Windows the “Express client”—we have similarly decided to call the HTTP Server (powered by Apache) product by a new generally accepted version of the feature name, “OS/400 Apache.” So from now on, if you see the term “OS/400 Apache,” you’ll know that we’re talking about IBM’s new HTTP Server (powered by Apache) feature. Got it? Okay, let’s go on.
IBM’s OS/400 Apache implementation is a compiled, OS/400-specific version of the server based on the Apache 2.0 alpha source code, which was tested and released last year, and the code is optimized to interact with OS/400 features and run on iSeries and AS/400 hardware. It’s not a true open-source product, because it’s being delivered as a set of compiled objects.
Although the Apache Software Foundation has recently released a beta version of the Apache 2.0 source code, IBM will not be implementing the new beta source code in OS/400 Apache until its next major refresh of that program, which is scheduled for the third quarter, 2001. It should be noted, however, that the iSeries is the first IBM eServer product to support Apache 2.0 (most other IBM HTTP Server implementations are based on the Apache 1.3.x release).
The iSeries should, in theory, be ahead of the curve when the final version of the Apache 2.0 code is released.
The Apache server delivered with OS/400 V5R1, inside the HTTP Server for iSeries (5769-DG1) feature, is pretty much the same implementation that is available with OS/400 V4R5 via PTF. Significant changes in the initial release of OS/400 Apache V5R1 this May include the addition of a triggered cache manager for better performance and WebCrawler support. Also, the Apache Administration and Configuration GUI—which configures both OS/400 Apache server and the original HTTP Server for AS/400, will now be the default ADMIN server—and this GUI runs on an OS/400 Apache-based server instance. (In the OS/400 V4R5 implementation, you have to explicitly ask for the new Apache-based administration GUI; the default ADMIN server in that release ran on an instance of the original HTTP Server.)
As far as plug-in modules go, IBM will add Apache Portable Runtime (APR) support in the third-quarter update of OS/400 Apache. The Apache Portable Runtime allows Apache modules to be written independently of the target deployment platform, with only a recompile required to run on iSeries. This theoretically means that modules that were developed for Apache servers running in other environments can be ported to the OS/400 Apache environment, giving iSeries-AS/400 users a large library of extended features they can use in their Apache Web server instances. With APR, OS/400 Web serving should be able to plug in to the open-source movement and participate in the benefits of an open- source product (something that is impossible with the original HTTP Server for AS/400, which does not contain this feature).
Also, since OS/400 Apache is still an early-release product, you should expect some cleanup in the third-quarter refresh as IBM provides items that were either incomplete or missing from the original implementation, such as logging and CGI capabilities. The refresh may also contain an updated version of WebSphere-OS/400 Apache integration. Released earlier this year as a technical preview, IBM stated at the time of this writing that WebSphere-OS/400 Apache integration is only appropriate for development, testing, and education. IBM expects that an upcoming version of this support (presumably the third- quarter refresh) will contain enough changes such that any previous WebSphere-OS/400 Apache configurations may be incompatible with the next version, possibly to the point of having to reconfigure applications that are using the technical preview support. For more information on WebSphere-Apache OS/400 integration, go to IBM’s WebSphere and IBM HTTP Server (powered by Apache) Web page at www-1.ibm.com/servers/eserver/iseries/ software/websphere/wsappserver/docs/apacheWebServerSupport35.html. For many shops, WebSphere integration is an important feature in OS/400 Apache server deployment, so stay tuned for more information. Finally, the server is scheduled to contain some additional enhancements in the third-quarter release that will make OS/400 Apache more equivalent to the original HTTP Server for AS/400, which has been available inside OS/400 since V4R3.
IBM says that the Apache-based server is available for production use and has the full level of IBM support behind it; you can call for service, write APARs, and expect PTFs. So, even though a major release of the product is scheduled for the third quarter, you could start prototyping and developing using OS/400 Apache right now. Just be aware that future changes to the OS/400 Apache server might have an adverse effect on your implementation, so I’m not sure I would use it for production deployment just yet. iSeries and AS/400 customers who experience problems using the OS/400 Apache server should report those problems to IBM for formal tracking and resolution.