An exciting week in the land of web server – if you’ve visited our Java One booth or been following the blog you already know that a preview of Sun’s JES Web Server 7.0 is now available for you to download.
7.0 is a new Major release and there is quite a bit new and improved indeed. If you are used to operating through the admin GUI the major change you will notice very quickly is the all-new admin.
On the other hand, if you’re the type to go looking at the actual installation, the major change you’ll notice right away is that the file layout is quite a bit different from previous releases.
Let me digress for a moment… One of my jobs here at Sun is as a member of Sun’s ARC (Architecture Review Committee). John Plocher has written to some length about Sun’s ARC process so I won’t repeat too much of that. One of the many goals of the ARC process is to make sure there is clarity as to which interfaces customers can rely on.
As long as you rely only on public Stable interfaces you will be assured that your code will continue to work in future releases (this is why you can take binaries you might’ve compiled on Solaris over 10 years ago and they still run on Solaris 10!). If, however, you build a dependency on any undocumented (private) interface, you must assume your code will break at any time without warning (usually at the worst possible time). Clearly, not a good idea.
(Please note that the word interface is used in a very broad sense. Anything you might depend on is an interface. APIs are interfaces, but so are CLI names and options, file locations, some output and so forth. Anything you might be able to build a dependency on can be an interface. Note also that Stable interfaces may in some cases also change – but only in Major releases with advance notice, so you’d have plenty of time to adjust.)
Why do I bring this up? Well, I’ll give a quick view of the file layout changes in 7.0 and I’ll also say a bit about where things fall with respect to their interface classification.
The web server file layout up to 6.1 harks back to the old iPlanet days and it had grown a bit messy over the years. In 7.0 things have been reorganized and cleaned up. Also, the layout makes it a bit easier for you to identify what you can rely on and what is off-limits.
If you look at the top-level installation directory here are a few important areas to note:
||This contains public binaries you can rely on. You can build
shell or other scripts using the commands you find here.
||This is a public directory containing include files you may need
when compiling code for use with the server.
||This is also a public directory, containing plugins you may
interact with directly.
||Here are code samples that demonstrate use of various features.
While this is (of course!) public for you to use, note that samples
are Unstable (which makes sense – the purpose of samples is to
showcase features, not to be relied on as-is).
||Unlike 6.1 where the admin server instance was named with the same pattern as regular instances, in 7.0 the admin server is always under this directory. Within admin-server, you can access the scripts in bin and the files in logs. Other subdirectories contain private implementation detail only.
||These are the server instances. As with admin-server, the bin and logs subdirectories are public. Unlike 6.1, the docs (default docroot) is unique to each instance and can be found here. Another major cleanup from 6.1 is that all the instance configuration lives in one place within the config directory – no more hunting for instance configuration among many top-level directories!
An important note about configuration files: while you may edit these manually with emacs (or lesser editors ;-), do not establish programmatic dependencies (e.g. sed scripts) on these. For scripting changes, go through wadm, the all-new CLI included in 7.0. By doing this you will isolate your scripts from any future config file format changes.
||This is a private directory. Its contents are not available for direct consumption, it only contains private implementation detail.
That’s the quick tour of the 7.0 file layout (I didn’t cover every detail here, but enough to get you started). Download the bits and play with them to see what else is new.
I should point out that while the interface details I’ve given here are unlikely to change significantly from now until the product is released, they may of course change. The current preview build is just a preview, after all, still subject to change. For the same reason, I didn’t write down precise interface levels, just a general description of each area. The formal product documentation which will be available when the production releasecomes out will contain the authoritative interface information.