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Mustang Beta Blog Carnival!

After nearly eighteen months of effort within Sun, the Java Community Process, and the wider JDK Community, the Mustang Beta Release is now available.

In contrast to the source and binary snapshots that we’ve been shipping for over a year, the formal beta release has been through many weeks of intensive testing—and a tiny little bit of last-minute bug-fixing—in order to produce a release that’s somewhat more polished. If you’ve chosen to avoid the riskier snapshot builds then now is the perfect time to have a look at Mustang, make sure your existing code still compiles and runs, and try out the new features. Please do let us know what you think or—even better—get involved and help us make Mustang a great release for the entire community!

To help celebrate the beta release I’m hosting a “blog carnival” right here on this page. Over the next couple of days many members of the Java SE development community will post blog entries about the work they’ve been doing for the Mustang release. As entries are posted I’ll add them here for convenient reference; alternatively you can get the very latest blog entries via Planet JDK, which also provides RSS and Atom syndication feeds.

Step right up, ladies and gentlemen…

• Chet Haase channels Julie Andrews and waxes poetic about his favorite Mustang features.

• Brian Doherty reflects on the meaning of the word “beta” in this modern age of continuous integration and snapshot releases, and talks about some of the performance improvements—and pitfalls—in the release.

• Chris Hegarty explains how he fixed a high-vote bug in the HTTP keep-alive implementation.

• Sundar shows how to use DTrace on Solaris to generate a mixed-mode stack trace whenever an exception is thrown.

• Jaya Hangal talks about LDAP timeouts and connection pooling in JNDI.

• Scott Violet takes a break from big-picture application architecture to highlight some of the smaller UI features in Mustang.

• Peter von der Ahé talks about the compiler plugins—known more formally as annotation processors—that are enabled by the Tree API, JSR 269, and JSR 199.

• Sean Mullan summarizes the new security features in the release.

• Shannon Hickey introduces the new support for choosing drop actions in the Swing Drag and Drop API.

• Mandy Chung shows off six techniques for diagnosing memory-usage problems.

• Madhura Dudhgaonkar explains why Mustang Beta is based on the relatively ancient build 59 even though the latest snapshot release is build 71.

• David Herron posts a helpful reminder of the Mustang Regressions Challenge, in which you can win a slick new Opteron-based Ultra 20 workstation if you find a really egregious regression. (No purchase necessary, void where prohibited by law, etc.)

• Éamonn McManus summarizes the new JMX features.

• Chris Campbell argues with himself over whether or not the beta build is too passé, and also takes stock of the work that he and his team have been doing.

• Preveen Mohan talks about some of the new AWT features in Mustang from the standpoint of a QA engineer.

• Naoto Sato describes the new Locale Sensitive Services SPI.

• Danny Coward muses on how the new Compiler API is going to keep javac up and running 24/7/365.

• Penni Henry, the new Mustang Program Manager, reflects on the quality of the release from the perspective of someone relatively new to the team.

• Gauri Sharma discusses the ongoing work on the Mustang JCK (Java Compatibility Kit).

• Jon Masamitsu wonders whether those who want a truly “pauseless” garbage collector would be willing to pay for it in the currency of time and space.

• Andreas Sterbenz shows how to plug NSS into the Java PKCS#11 crypto provider in order to improve performance on Linux and Windows.

• Finally, in my other blog you can find a description of the new class-path wildcard feature.

That’s it for now!

Questions and answers

To answer a few of the questions that’ve been asked in the comments below:

• The beta release is based on weekly build 59 from way back in November 2005. Madhura talks a bit more about why it’s so “old.”

• Every bug fixed in a later snapshot build will stay fixed for the final release unless a problem with the fix is found in the interim and no alternative solution can be devised.

• The evaluation license is a bit, well… baroque. We’re talking to our legal team to see if the part about having to notify Sun can be removed.

Mustang Release Contents (JSR 270): Early Draft Review

Just in time for the holidays!

The Early Draft Review version of the JSR 270 specification, which governs the content of the Java SE 6 “Mustang” release, is now available.

JSR 270 is an “Umbrella” JSR, so it doesn’t define specific features itself—instead it lists features defined in other JSRs, or in the concurrent maintenance review of the Java SE platform specification. As an improvement over past umbrella specifications, this time around we’ve augmented each feature description with non-normative links to the relevant draft Mustang javadoc as well as any associated JSRs or other material.

When reviewing this draft please keep in mind that the Umbrella JSR only covers the component JSRs and other big-ticket or highly-visible items in Mustang. Most smaller enhancements aren’t listed in the Umbrella JSR, though of course they will be covered in the maintenance review of the platform specification that’ll start around the time that the beta release of the reference implementation ships.

Mustang is still under development. The JSR 270 Expert Group has approved all of the features listed in the draft, and we expect to see all those features in the final release. It’s still possible, however, for a feature to be dropped if, for example, it turns out to be too difficult to implement. It’s also possible for new features to be added, given sufficient justification, though at this stage big changes to the overall shape of the release are pretty unlikely.

Comments on this draft are most welcome! The formal EDR period ends in sixty days, but you can send feedback to the e-mail address listed in the draft at any time.

Sneak Preview

Here’s a summary of the approved feature list sorted by area, component, and feature name. For more details please see the EDR specification.

You can check out the initial implementations of many—though not all—of these new features in the weekly snapshot builds of the reference implementation.

Mustang Component JSRs

The JSR 270 Expert Group recently decided upon the set of component JSRs that will appear in Mustang, a.k.a. Java SE 6. Here they are, grouped together by area:

There are a few differences between this set and the set originally proposed in JSR 270:

• JSR 173, the Streaming API for XML, was added; it's a prerequisite for both JAXB 2.0 and JAX-WS 2.0.
• JSRs 181 (WS Metadata), and 250 (Common Annotations) were added; these are prerequisites for JAX-WS 2.0.
• There is no JSR for "JAXP.next"; instead a minor maintenance revision of JAXP will be proposed for Mustang.
• JSR 268, the Java Smart Card I/O API, was dropped. Platform implementors are of course free to deliver an implementation of this JSR alongside their Java SE 6 implementations, which is what Sun intends to do, but JSR 268 won't be a required part of the platform.

Mustang's final release is slated for the third quarter of 2006. A lot could change between now and then, but unless something truly surprising happens then these are the JSRs that will appear in Mustang.

Mustang: Experts Wanted

JSR 270, the umbrella JSR for J2SE 6.0 ("Mustang"), was resoundingly approved by the JCP Executive Committee for J2SE/J2EE earlier this week.

The expert group already has some initial members; we'll be accepting additional applications through Monday, 14 March. We won't be able to accept every application, of course, since we'll need to strike a balance between having broad representation from the community and having a manageable group that can make decisions in real time. If you'd like to help guide the future direction of the platform, please consider applying to join.

Mustang Snapshots: Another experiment in openness

Way back when I was an undergrad I had a professor who was a stickler for experimental method. She was also, however, always anxious to see what you had learned. As soon as she understood your experimental setup -- which was usually before the end of your explanation of it -- she'd insistently ask, "What were your results?" Between her enthusiasm for the question and her eastern-European native tongue the last word would always come out as "RHEE-zults". That question, and her unique pronunciation, have stuck in my head ever since...

Last June we did a first "experiment in openness" with the Tiger Snapshots. We posted each weekly Tiger build, in binary form, from the Beta 2 release right up to the Release Candidate. The results were positive: About ten thousand brave souls downloaded the builds and filed several dozen bugs, and the most critical handful of those bugs was fixed in time for the RC build.

Inspired by the success of the Tiger snapshots, today we posted the first of the Mustang Snapshots. We've made some significant changes this time around:

• We've started earlier. You can get build twelve today. Yes, that's twelve as in 12. There aren't a whole lot of changes in this build, mainly just bug fixes and a few small enhancements here and there, but you'll see more change going forward as new features are integrated.

  As usual, snapshot builds are not for the timid. They receive only limited testing -- just a few hours' worth to make sure that they're warm and breathing. If you want stability then you'd best wait for the Mustang beta release, but if you enjoy living on the bleeding edge then these builds are for you.

• We're shipping source bundles. For the first time ever we're shipping source bundles for a J2SE release while it's under active development (gulp). This should make it easier for interested developers to contribute to the release as it evolves. In past releases the only ways to do that were to be lucky and know someone at Sun, or be lucky and have your suggestion survive the labyrinthine gauntlet of the bug-submission process.

  Posting source bundles will also make it easier for us to be embarrassed by our mistakes, but we're quite happy to be arbitrarily embarrassed in exchange for higher quality.

• We're using java.net. One of the big goals here is to engage better with the developer community, and java.net provides excellent infrastructure for that. The bundles are being hosted in the overall j2se project, which will shortly acquire the other usual project accoutrements such as mailing lists and forums. We're also working on a streamlined process for patch submission so that you can send code directly to real live JDK engineers rather than paste it into a bug report, cross your fingers, and hope for the best.

• We're using a new license. The source bundles are covered by the Java Research License. The JRL is, to my non-lawyerly brain, a big improvement over the old SCSL license -- for one thing, I can understand it! The JRL also gives developers and researchers more flexibility than SCSL did, though it's still not an actual open source license in OSI terms (sorry).

Taken together these changes obviously entail a much bigger, and longer, experiment than the Tiger Snapshots. We certainly don't want to wait until the end to learn from the experience and make adjustments. If you have ideas on how we could do any of this better, please let us know!

Tigers and Mustangs and Dolphins, Oh My!

Tiger is done.

Whew! I can just about hear the collective sigh of relief from everyone, both inside and outside of Sun, who contributed to this amazing product. We hope you enjoy working with it. As I've said before, I think Tiger is the highest-quality JDK that we've ever built -- and I've been helping to build these things since JDK 1.1.

This seems an appropriate time to look forward, and in particular at some changes that we're making to the J2SE release model.

The current model has three kinds of releases:

• Feature releases are the big ones (1.3, 1.4, 1.5 5.0), with tons of bug fixes and lots of new features. These have generally been about 24-36 months apart.
• Maintenance releases, the so-called "dot-dot" releases (1.4.1, 1.4.2, etc.), have lots of bug fixes but no new API features. Lately these have been about 8-10 months apart.
• Update releases, the so-called "underscore" releases (1.4.2_01, 1.5.0_01 5.0 update 1), which contain a very small number of bug fixes (typically around 100) carefully chosen to meet urgent customer needs. Sun has shipped these about every 3-4 months.

• Feature releases will ship every 18-24 months. This will allow the platform to evolve more rapidly so as to better meet the needs of the developer community and compete with .NET.
• There won't be any more maintenance releases. Starting with Tiger (5.0) there won't be any more releases the size of 1.4.1 and 1.4.2, i.e., with 1500-2000 bug fixes. There still might be a release called "5.1", but it will just be a special update release.
• Update releases will ship every 2-3 months. This will make it possible for critical bug fixes to be delivered to customers in a more timely manner.

• Releases will more likely ship on time. Within the J2SE engineering organization we've long wrestled with the difficult choice of making the current maintenance release as perfect as possible versus working on great new features for the next big feature release. This conflict has been the proximate cause of many schedule slips over the years. The new release model finally resolves this fundamental tension: J2SE engineers will, by default, always be working on the next feature release. There will be times when they're asked to fix a critical bug in an update release, and even rarer times when some nontrivial work (e.g., to improve performance) will be done in an update release, but these will be the exceptions rather than the rule.
• Release adoption will improve. The existing medium-sized maintenance releases have long been a big adoption barrier. Due to the level of change in these releases many users have only been confident enough to adopt them after requalifying all of their applications -- in other words, by treating them much like feature releases in terms of testing. Most users are confident enough in the update releases to just "drop them in" without doing a lot of testing; now they'll be able to do so for a longer time in between feature releases.

Tough and Trustworthy Tigers

The Tiger Release Candidate shipped earlier today.

Even more amazingly, our QA team is happy with it!

Our hard-working QA team recently presented a summary of their results based on the near-final builds of Tiger. Overall this is looking to be the most stable and reliable JDK that we've ever shipped. Here are the highlights of their report:

• Applet compatibility     We test a set of over 400 applets, nearly all of which are external, to make sure that they run as well on Tiger as they do on any other popular VM, most especially the old and somewhat quirky VM from Microsoft. 97% of these tests pass, which is a much higher fraction than for any previous JDK release. The few failures are mostly due to applets that are relying on behavior that's outside the scope of the J2SE specification.
• Reliability     We run a set of five large server-class applications, including Sun's own application server, another well-known application server, and Tomcat, on some big iron under heavy load to see how long they stay up. As of this writing they've been up and running continuously for 28 days -- at some point we'll have to decide when to shut them off. This is a much longer uptime than we've achieved in previous releases.
• Conformance     The 1.5 JCK (Java Compatibility Kit) contains a whopping 45,194 tests (for comparison, the 1.4.2 JCK had a mere 27,309 tests). Tiger passes all of them.
• Regression tests     These are tests written by development engineers to make sure that a bug gets fixed and stays fixed. 99.7% of the tests in the regression-test suite pass. We've carefully reviewed the few failures, and in all cases we decided that the risk of fixing them at this late stage outweighs their relatively small end-user impact.
• Functional tests     These are tests written by quality engineers to test the overall functionality of the JDK. 99.7% of the tests in the functional-test suite pass. As with the failing regression tests, fixing the few remaining failures is just not worth the risk right now.

A total of 8,002 features, enhancements, and bug fixes were integrated into Tiger, so when I step back and think about it this way I'm fairly amazed that it's working so well.

Tiger is the highest-quality JDK that we've ever built. Is it perfect? No, of course not. There are no doubt still some bugs lurking, but hopefully none is too serious. If Tiger quality is important to you then please download and test the release candidate and let us know right away if something's wrong. The next couple of weeks are our last chance to fix any thermonuclear, hair-on-fire, sky-is-falling showstopper bugs.

Tiger Snapshots: An experiment in openness

Last Friday we posted the first of the Tiger Snapshot releases to the web. Build 55 is available right now, and the plan is to post each weekly build until we reach the Release Candidate (RC) build. Unlike our milestone releases these builds receive only limited testing, so they're not for the feint of heart. If you'd like to live on the bleeding edge, though, then these builds are for you.

Our main motivation for doing the snapshot releases is to ensure that the FCS release of J2SE 1.5.0 is of the highest possible quality. The end-game of a big software release, as anyone who's survived one knows, is a particularly tense time during which every change is closely scrutinized, lots of hard decisions must be made, and there's never enough testing. By posting each weekly build on the web we're hoping to increase the level of external testing and thereby improve the quality of the final result.

A second motivation for doing the snapshot releases is to gain some more experience with the "release early, release often" development style that's been so successful in the Open Source community. The Tiger Snapshot model isn't exactly "release early", since these are post-Beta 2 builds, and it's not quite as "often" (i.e., nightly) as some projects, but it's a more aggressive one than we've ever tried before. If this experiment goes well then we'll consider releasing even earlier and oftener in future releases.

This work is licensed under a Creative Commons License.